046
046
To cite this article: Denis P. Wood, Colin Glynn, Conor O’Dea & Darren Walsh (2014) Physical and empirical
models for motorcycle speed estimation from crush, International Journal of Crashworthiness, 19:5, 540-554, DOI:
10.1080/13588265.2014.918300
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                                                                                   International Journal of Crashworthiness, 2014
                                                                                   Vol. 19, No. 5, 540554, http://dx.doi.org/10.1080/13588265.2014.918300
                                                                                                    Physical and empirical models for motorcycle speed estimation from crush
                                                                                                                  Denis P. Wooda, Colin Glynna*, Conor O’Deaa,b and Darren Walshc
                                                                                   a
                                                                                       Denis Wood Associates, Isoldes Tower, Dublin, Ireland; bSchool of Engineering, Trinity College Dublin, Ireland; cDr JH Burgoyne &
                                                                                                                                       Partners LLP, Hertfordshire, UK
                                                                                                                             (Received 1 November 2013; accepted 23 April 2014)
                                                                                           This paper presents a new physical model for estimating motorcycle speed in motorcycle to car collisions from the
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                                                                                           motorcycle wheelbase reduction and car deformation depth. This model combines previously published specific energy
                                                                                           characteristics of motorcycles and scooters derived from barrier tests with a motorcycle to car interface ForceBalance
                                                                                           approach to estimate the collision energy absorbed by the car. This ForceBalance approach and three previously
                                                                                           published models for motorcycle speed estimation are compared using a data-set of 107 published staged collisions, over a
                                                                                           collision speed range of 30122 kph. The ForceBalance model and a previously published empirical model were shown
                                                                                           to compare well with the available staged tests, with statistically insignificant mean residuals of 0.8 and 0.7 kph for the
                                                                                           predicated speed when compared with actual speeds. The corresponding standard errors were 10.3 and 11.2 kph,
                                                                                           respectively. Two other previously published physical models were shown to significantly under-predict speed, with mean
                                                                                           residuals of 5.6 and 19.5 kph, respectively, with corresponding standard errors of 9.5 and 11.8 kph. An analysis of impacts
                                                                                           into hard and soft areas of the car sides show that the presented ForceBalance model is robust when applied to both soft
                                                                                           and hard impact locations, while the empirical approach is shown to be robust for soft impact locations but under-predicts
                                                                                           collision speed by a mean of 3 kph for hard impact locations.
                                                                                           Keywords: motorcycle/scooter collisions; speed estimation; car deformation; motorcycle; wheelbase deformation; wheel-
                                                                                           base shortening
                                                                                   And Moa is the overall equivalent mass of the colliding              types in Table A2. The scooter specific energy character-
                                                                                   pair as detailed in the following:                                   istics bounded those of the motorcycles. Statistical cross-
                                                                                                                                                        comparison between the scooter and motorcycle data
                                                                                                               Mm=c Mcar                                showed that they could be treated as a common
                                                                                                      Moa ¼               :                     ð3Þ
                                                                                                              Mm=c þ Mcar                               population.
                                                                                                                                                             By comparison, Searle [18] obtained the relation for
                                                                                       For impacts offset from the centre of gravity of the car         specific energy of
                                                                                   the effective mass of the car, derived from the offset of
                                                                                   the line of action of the motorcycle velocity vector, is                                   SE ¼ 703dw2 :                    ð8Þ
                                                                                   used.
                                                                                                                                                            This is based on a linear forcedeflection model for
                                                                                                                                   
                                                                                                                             k2                         motorcycle wheelbase deformation and is derived from a
                                                                                                  Mcar;eff ¼ Mcar                    ;          ð4Þ     combination of barrier (N ¼ 13) and motorcycle to car
                                                                                                                        ðk 2 þ h2 Þ
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                                                                                                                                                        3. Alternative models
                                                                                                   SE ¼ 641:7ðdw þ 0:1Þ1:89 ;                   ð7Þ
                                                                                                                                                        3.1.   Wood original model [25]
                                                                                   where dw ¼ average residual wheelbase shortening of                  This approach uses Equations (1)(4) in combination
                                                                                   motorcycle/scooter, obtained from the average residual               with the specific energy relation for motorcycles and
                                                                                   wheelbase of the deformed motorcycle/scooter and                     scooters derived from barrier test data, Equation (7) and
                                                                                   knowledge of the un-deformed wheelbase length.                       the empirical equation for car energy, Equation (9), to
                                                                                       The barrier test data used by Wood [25] to derive the            estimate collision closing speed.
                                                                                   population specific energy characteristics includes eight
                                                                                   types of scooter and six types of motorcycle, produced
                                                                                   between the early 1980s and the present day. The motor-              3.2.   Searle model [18]
                                                                                   cycles and scooters used are detailed in Table A2 of                 The Searle model is based on linear force deformation of
                                                                                   Appendix 2.                                                          the motorcycle fork assembly, Equation (8) and a
                                                                                       Individual specific energy characteristics were derived          ‘forcebalance’ approach for car energy estimation. In
                                                                                   for the first four scooter types and the first two motorcycle        conjunction with Equations (1)(4) this yields a collision
                                                                                   542                                                     D.P. Wood et al.
                                                                                                                                  12               4. Comparison
                                                                                                       Mm=c
                                                                                              Vccs   ¼      ð1406Þðdw þ dcar Þðdw Þ :         ð11Þ
                                                                                                                                                     The different models can be compared in two ways. First,
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                                                                                                       Moa
                                                                                                                                                     each approach can be applied to all independent staged
                                                                                                                                                     test data available for the respective models from the
                                                                                   3.3. Schmidt Empirical model [17]                                 available set of 107 staged tests, with those staged tests
                                                                                   The empirical model for estimation of collision closing           used for model development excluded. The 107 staged
                                                                                   speed derived by Schmidt [17] is                                  tests were carried out and published by various research-
                                                                                                                                                     ers, see Table A4 of Appendix 4 for details. The second
                                                                                                Vccs ¼ 7:02 þ 35:52dw þ 15:5dcar :            ð12Þ   approach is to use a common subset of independent staged
                                                                                                                                                     tests. The common subsets are those tests which were not
                                                                                                                                                     used in the development of any of the compared models.
                                                                                   3.4. ForceBalance model                                          This approach is used to compare the Searle, Schmidt and
                                                                                   From Equations (1)(7) and (10), including offset, the            ‘ForceBalance’ models. The available data-sets are
                                                                                   ‘ForceBalance’ model yields the estimation for collision         detailed in Table 1 while Table 2 sets out the range of
Independent data for each model Wood Original Schmidt Empirical Searle ForceBalance
                                                                                   N                                                   76                          87               63                 107
                                                                                   Mean residual                                        4.95                        0.65            19.17                0.77
                                                                                   SE of residual                                       9.49                       11.22            11.79               10.25
                                                                                   t                                                    4.55                        0.54            12.91                0.78
                                                                                   Regression of residuals        Intercept            11.22                        0.68            24.75                4.15
                                                                                                                  Slope                0.09                        0.00            0.10              0.05
                                                                                                                  r2                    0.030                       0.000            0.028               0.007
                                                                                   parameter values (motorcycle mass, impact speed, etc.)              distribution of collisions classified as hard or soft is
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                                                                                   for each of the four models.                                        64%69% soft and 31%36% hard, and provide a fair
                                                                                       It is apparent from Table 2 that a majority of the              comparison between each of the models in this regard.
                                                                                   parameters listed show relatively similar values across the         The percentage of staged tests in each of the data-sets
                                                                                   respective data-sets. The mean mass of the motorcycles              involving scooters instead of motorcycles is varied, rang-
                                                                                   ranges from 186209 kg with an overall minimum and                  ing from 3% to 14%. However, it was shown in [25] that
                                                                                   maximum of 74.5 and 329 kg, respectively. The mean                  motorcycles and scooters can be regarded as a common
                                                                                   mass of the cars ranges from 11101181 kg with an over-             population when considered in specific energy terms.
                                                                                   all minimum and maximum of 594 and 1769 kg, respec-
                                                                                   tively. This results in similar mean ratio of the mass of the
                                                                                   motorcycle to the mass of the car at 1:5.3 to 1:6.2. The            4.1.   Independent data-sets
                                                                                   mean wheelbase reductions are the same for each subset              Table 3 shows the results for each model where all inde-
                                                                                   at 0.25 m with an overall minimum and maximum of 0.08               pendent staged data available for each model are used, i.e.
                                                                                   and 0.48 m, respectively. The mean car deformation is in            all data from the 107 staged tests, which were not used in
                                                                                   a comparably tight range of 0.290.31 m with an overall             the particular model development. Figures 14 show the
                                                                                   minimum and maximum of 0.038 and 0.9 m, respectively.               comparison between actual collision closing speed, Va ,
                                                                                   The range of closing speed, Vccs , varies from an overall           and predicted collision closing speed, Vp . Note that the
                                                                                   minimum of 30 kph to a maximum of 122 kph. The                      speeds shown in all the figures are in kph.
                                                                                       Regression of the residuals, Va  Vp , against Vp,                   both approaches under-predict the actual collision closing
                                                                                   shows that the distributions are independent of speed. The               speed (in almost all cases for the Searle model). For both
                                                                                   range of standard error values is 9.511.8 kph. Chi-square               the Schmidt Empirical model and the ‘ForceBalance’
                                                                                   tests show no significant difference between standard                    model, the mean residuals of 0.65 and 0.77 kph are not
                                                                                   errors. The mean residuals for the Searle model, 19.1 kph,               statistically significant with t values of 0.54 (P ¼ 59%)
                                                                                   and Wood Original model, 5 kph, show that on average                     and 0.78 (P ¼ 44%), respectively.
                                                                                   Table 4. Searle, Schmidt Empirical and ForceBalance mod-           Table 5. Schmidt Empirical and ForceBalance models, 87
                                                                                   els, 63 common data results.                                        common data results.
                                                                                   N                                   63        63       63           N                                      87         87
                                                                                   Mean residual                       19.17      0.77     0.29        Mean residual                           0.65       1.1
                                                                                   SE of residual                      11.79     12.26    11.18        SE of residual                         11.22      10.46
                                                                                   t                                   12.91      0.50     0.21        t                                       0.54       0.98
                                                                                   Regression of residuals Intercept   24.75      0.02     4.56        Regression of residuals   Intercept     0.68       4.32
                                                                                                           Slope       0.10      0.01    0.06                                  Slope         0.00      0.04
                                                                                                           r2           0.028     0.000    0.010                                 r2            0.000      0.007
                                                                                   546                                                      D.P. Wood et al.
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Figure 5. Schmidt Empirical model, 63 independent Searle data, V actual vs. V predicted.
                                                                                   under-predictions of 0.65 and 0.77 kph, respectively.                compared to their available staged tests, with mean under-
                                                                                   Their corresponding t-values are 0.54 (P ¼ 59%) and 0.78             predictions of 19.2 and 5 kph, respectively. The Wood
                                                                                   (P ¼ 44%) which are not statistically different from zero.           Original model [25] was originally validated using 13
                                                                                      However, the Searle and Wood Original approaches                  independent staged tests with a mean residual of 2.5 kph,
                                                                                   have been shown to under-predict collision speed when                a standard deviation of 11.5 kph and a statistically
Independent soft/hard data Schmidt Empirical soft ForceBalance soft Schmidt Empirical hard ForceBalance hard
                                                                                   N                                             60                      73                    27                      34
                                                                                   Mean residual                                 0.40                    0.62                  3.00                    1.09
                                                                                   SE of residual                                10.18                    9.73                 13.17                   11.33
                                                                                   t                                             0.30                    0.54                  1.18                    0.56
                                                                                   Regression of residuals   Intercept           4.47                   0.43                  9.09                   10.45
                                                                                                             Slope                0.05                    0.01                 0.08                   0.13
                                                                                                             r2                   0.01                    0.00                  0.018                   0.062
                                                                                   insignificant t-value of 0.77 (P ¼ 46%). When the Wood               and shows that the distribution is ‘normal’. In all of the
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                                                                                   Original model is applied to the larger independent 76               comparisons, the standard error for the ‘ForceBalance’
                                                                                   data-set the mean residual increases to 5 kph while the              approach is less than that obtained for the Schmidt model
                                                                                   standard error shows a decrease to 9.5 kph, with a statisti-         (11.2 kph versus 12.3 kph for the 63 Searle data-sets, and
                                                                                   cally significant t-value of 4.55 (P ¼ 0%).                          10.5 kph versus 11.2 kph for the 87 Schmidt data-sets).
                                                                                        Comparison between actual collision closing speed,              An explanation for the difference is that the Schmidt
                                                                                   Va , and predicted collision closing speed, Vp , for all four        model does not take into account the influence of variation
                                                                                   approaches shows that the trend of Va against Vp can be              in the motorcycle/scooter and car masses. When the
                                                                                   considered to be 1:1. This is confirmed by the regression            ‘ForceBalance’ model is applied to the data-sets with
                                                                                   of residuals Va  Vp against Vp with the extremely low               the mass component excluded from Equation (13) the
                                                                                   regression coefficients, r2 , detailed in Table 2. This shows        standard error increases (12.5 kph for the 63 Searle data-
                                                                                   that the distributions of residuals for all four approaches          sets, and 11.5 kph for the 87 Schmidt data-sets) when
                                                                                   can be considered to be independent of speed over the pre-           compared to Equation (13) where the mass effect is
                                                                                   dicted Vp range for the Va range of 30122 kph.                      included. The scatter in the data reflects the range of vari-
                                                                                        The standard errors for all four approaches are similar,        ation in the structural characteristics of the motorcycle/
                                                                                   with the Wood Original and ‘ForceBalance’ approaches                scooter and car populations with structurally ‘soft’
                                                                                   having the lowest values. Figure 7 shows the cumulative              vehicles resulting in over-prediction of collision speed
                                                                                   distribution of residuals for the ‘ForceBalance’ model              and under-prediction for structurally ‘hard’ vehicles.
                                                                                   Figure 7. Cumulative distribution of ForceBalance using 107 independent data compared with normality.
                                                                                   548                                                      D.P. Wood et al.
                                                                                   5.1.     Car ‘hard’ and ‘soft’ structures                            However, this is within the 95% confidence range of
                                                                                   It is common case that the structural characteristics of the         9.813.2 kph for the standard error of 11.2 kph. The
                                                                                   sides of cars vary along the length of the cars. The struc-          ‘hard’ data yields a mean residual of 3 kph with a corre-
                                                                                   turally ‘hard’ areas are typically:                                  sponding t ¼ 1.18 (P ¼ 24%). These results indicate that
                                                                                                                                                        the Schmidt Empirical model is very robust when applied
                                                                                          (1) the wheels;                                               to soft data but when applied to ‘hard’ data, i.e., ‘hard’
                                                                                          (2) the A, B or C pillar;                                     impact locations on the sides of cars, results in a mean
                                                                                          (3) the firewall-front bulkhead.                              under-prediction of the collision speed of 3 kph.
                                                                                                                                                            For the ‘ForceBalance’ model the ‘soft’ data yields a
                                                                                       Wood [24] using the Wood Original [25] approach                  mean residual of 0.6 kph, with a t ¼ 0.54 (P ¼ 59%) while
                                                                                   found that impacts against the ‘hard’ portions of the car            the ‘hard’ data yields a mean residual of 1.1 kph with t ¼
                                                                                   sides resulted in significant under-prediction of collision          0.56 (P ¼ 58%). The standard errors of 9.7 and 11.3 kph
                                                                                   speed by 10%.                                                        are close to the overall data-set value of 10.3 kph and
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                                                                                       For the available data-sets of staged collisions (87 for         within the 95% confidence range of 9.011.8 kph. The
                                                                                   Schmidt Empirical and 107 for ForceBalance) the distri-             similarity in the mean residual, standard error and t-values
                                                                                   bution of collisions classified as hard or soft is 68%69%           for the ‘ForceBalance’ model when applied to either the
                                                                                   soft and 31%32% hard, and provide a fair comparison                 soft or hard data indicates that this model provides a
                                                                                   between these two models in this regard.                             robust prediction of collision speed regardless of whether
                                                                                       Table 6 shows the results for both the Schmidt Empiri-           the impact is at a structurally soft or hard location on the
                                                                                   cal and ‘ForceBalance’ models when applied to their                 car. This is explained by the manner of the physical model
                                                                                   independent hard/soft data while Figures 8 and 9 show the            used where an increase in motorcycle wheelbase deforma-
                                                                                   comparison between actual collision closing speed, Va ,              tion due to impacting a ‘hard’ area of a car yields an
                                                                                   and predicted collision closing speed, Vp , for Schmidt              increase in the contribution of motorcycle deformation to
                                                                                   ‘hard’ and ‘ForceBalance’ ‘soft’ impact areas, respec-              the speed estimation, refer to Equation (13).
                                                                                   tively. For the Schmidt Empirical model, the ‘soft’ data
                                                                                   yields mean residual of 0.4 kph, which shows a slight
                                                                                   over-prediction when compared to both the 63 Searle and              5.2. Angled collisions
                                                                                   87 independent results.                                              The database of 107 published staged collisions includes 9
                                                                                       For the Schmidt Empirical model with the ‘hard’ data             angled collisions and 98 broadside (90 ) collisions, see
                                                                                   the standard error is seen to increase to 13.2 kph.                  Table A4 of Appendix 4. The angled collisions were
                                                                                   Figure 8. Schmidt Empirical model, 27 independent hard data, V actual vs. V predicted.
                                                                                                                              International Journal of Crashworthiness                                           549
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                                                                                   within 45 of the broadside collision, i.e. a collision angle        with 1.47 kph) or standard error (10.3 kph compared with
                                                                                   range of 45 135 , as shown in Figure A4 of Appendix 4.            11.1 kph) with a t-test value of 0.21 (t-critical ¼ 2.26) and
                                                                                       A comparison of the 90 and angled collisions for the            an F-value of 0.05 (F-critical ¼ 3.93).
                                                                                   ForceBalance model shows no statistically significant                   Figure 10 shows the comparison between actual colli-
                                                                                   difference in either the mean residual (0.66 kph compared            sion closing speed, Va , and predicted collision closing
                                                                                   Figure 10. ForceBalance model, nine angled collisions, V actual vs. V predicted.
                                                                                   550                                                  D.P. Wood et al.
                                                                                   speed, Vp , for the nine angled collisions using the Force-    locations but to have under-predicted by a mean value of
                                                                                   Balance model together with the 1:1 line.                     3 kph for hard impact locations.
                                                                                                                                                      In conclusion, both the ‘ForceBalance’ and Schmidt
                                                                                                                                                  Empirical approaches are shown to predict collision clos-
                                                                                   6. Conclusion                                                  ing speed from motorcycle/scooter wheelbase deforma-
                                                                                   This paper compares four approaches to the estimation of       tion and car body deformation over the speed range of
                                                                                   motorcycle collision speed from motorcycle/scooter and         30122 kph with standard errors of 10.3 and 11.2 kph,
                                                                                   car deformation. Three approaches, Wood [25], Schmidt          respectively. The Schmidt empirical model has the merit
                                                                                   [17] and Searle [18], have been previously published but       of being simple in application. The ‘ForceBalance’
                                                                                   either without comparison with independent data, Searle        model has the merit of being based on a physical represen-
                                                                                   [18], or comparison with small data-sets, Wood [25] (N ¼       tation and being able to accommodate variation in vehicle
                                                                                   13) and Schmidt [17] by Bartlett [2] (N ¼ 25). Here, a         masses.
                                                                                   database of up to 107 published staged tests is used.              When applying the ForceBalance approach to indi-
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                                                                                       The new model set out in this paper applies the princi-    vidual collisions a number of factors need to be taken into
                                                                                   ple of ‘ForceBalance’ at the interface between the            account. There must be clear penetration of the front
                                                                                   motorcycle/scooter and car to estimate the collision           wheel of the motorcycle/scooter into the side of the car.
                                                                                   energy absorbed by the car. This ‘ForceBalance’ is com-       The collision angle of the motorcycle/scooter into the car
                                                                                   bined with previously published (Wood [25]) specific           must be within 45 of a broadside impact. The front forks
                                                                                   energy characteristics for motorcycles and scooters. This      and assembly, while deformed, must be intact and not
                                                                                   model is compared against the 107 staged test database.        fractured or broken away.
                                                                                       A comparison of each of the models with the available
                                                                                   staged tests show that the ‘ForceBalance’ model and the       References
                                                                                   Schmidt [17] empirical model both demonstrate a good            [1] K.S. Adamson, P. Alexander, E.L. Robinson, G.M.
                                                                                   comparison with the data. Wood Original [25] and Searle             Johnson, C.I. Burkehead, J. McManus, G.C. Anderson,
                                                                                   [18] are shown to significantly under-predict impact speed          R. Aronberg, J.R. Kinney, and D.W. Sallmann, 17 motor-
                                                                                   when compared with the available data. The                          cycle crash tests into vehicles and barriers, SAE paper
                                                                                   ‘ForceBalance’ model and the Schmidt Empirical model               2002-01-055, 2002.
                                                                                                                                                   [2] W. Bartlett, B. Focha, and C. Kauderer, 25 moving motor-
                                                                                   have mean residuals of 0.8 and 0.7 kph and standard errors          cycle into stationary car tests: CA2RS 2009 data, July/
                                                                                   of 10.3 and 11.2 kph, respectively. With t-values of 0.78           August 2013, test carried out in Sonomoma County Air-
                                                                                   and 0.54 the mean residuals are shown to be statistically           port, Santa Rosa, CA, 2009.
                                                                                   insignificant. The Wood Original [25] and Searle [18] had       [3] V. Craig, Compiles for motorcycle/auto crash test results,
                                                                                   mean residuals of 5.0 and 19.2 kph and reflect the signifi-         November/December, 2012, tests conducted by the Uni-
                                                                                                                                                       versity of Tulsa Consortium, hosted by New York State-
                                                                                   cant under-prediction of collision speed.                           wide Traffic Accident Reconstruction Society, 2012.
                                                                                       A common subset of 63 staged tests from the total 107       [4] V. Craig, Motorcycle/van high-speed crash test, Accident
                                                                                   database not used in the development of any of the                  Investigation Q, 51(summer) (2008), pp. 2627.
                                                                                   ‘ForceBalance’, Schmidt, and Searle models were used           [5] CTS crashtest-service.com, Test 10402, 1994. Available at
                                                                                   to compare the three. The mean residuals of 0.8, 0.3 and            http://www.crashtest-service.com/WEB_GB/start.asp.
                                                                                                                                                   [6] CTS crashtest-service.com, Test 11374, 1995. Available at
                                                                                   19.2 kph, respectively, highlight the degree of under-pre-          http://www.crashtest-service.com/WEB_GB/start.asp.
                                                                                   diction in the Searle model relative to the other               [7] CTS crashtest-service.com, Test 11382, 1995. Available at
                                                                                   approaches. The t-values are 0.21 (P ¼ 83%), 0.51 (P ¼              http://www.crashtest-service.com/WEB_GB/start.asp.
                                                                                   61%) and 12.91 (P ¼ 0%), respectively. This shows that          [8] CTS crashtest-service.com, Test 14613 (test carried out by
                                                                                   while mean residual of the ‘ForceBalance’ and Schmidt              J. Priester and M. Weyde), 2005. Available at http://www.
                                                                                                                                                       crashtest-service.com/WEB_GB/start.asp.
                                                                                   model are statistically insignificant, the mean residual of     [9] CTS crashtest-service.com, Test 16225 (test carried out by
                                                                                   the Searle model is not so.                                         J. Priester and M. Weyde), 2008. Available at http://www.
                                                                                       A common subset of 87 staged tests was used to fur-             crashtest-service.com/WEB_GB/start.asp.
                                                                                   ther compare the ‘ForceBalance’ and Schmidt                   [10] CTS crashtest-service.com, Test 16226 (test carried out by
                                                                                   approaches. The mean residuals are 1.1 and 0.7 kph,                 J. Priester and M. Weyde), 2008. Available at http://www.
                                                                                                                                                       crashtest-service.com/WEB_GB/start.asp.
                                                                                   respectively, which with t-values of 0.98 (P ¼ 33%) and        [11] G.K. Kasanicky, P. Kohut, and J. Priester, Analysis of Sin-
                                                                                   0.54 (P ¼ 59%) are statistically insignificant. However,            gle-Track Vehicle Accidents, Zilina University Publishers,
                                                                                   the under-prediction by the ‘ForceBalance’ model is                Zilina, 2003.
                                                                                   higher, on average, than the Schmidt model by 0.4 kph.         [12] R. Limpert, Motor Vehicle Accident Reconstruction and
                                                                                       The sides of cars have structurally ‘hard’ and ‘soft’           Cause Analysis, 5th ed., Michie Pub, Charlottesville,
                                                                                                                                                       VA, 1994.
                                                                                   areas. The ‘ForceBalance’ model is robust for both hard       [13] J. Priester and M. Weyde, Tests carried out in 2005. CD-
                                                                                   and soft impact locations while the Schmidt [17] empiri-            ROM, Ingenieur- und Kfz Sachverstandigenburo Priester
                                                                                   cal model is shown to have been robust for soft impact              und Weyde, Saarbr€  ucken, Berlin, 2005.
                                                                                                                               International Journal of Crashworthiness                                           551
                                                                                   [14] J. Priester and M. Weyde, Tests carried out in Berlin in      SE    ¼    specific energy (Nm/kg)
                                                                                        July and September 2000. CD-ROM, Ingenieur-und Kfz-             t   ¼    t-test value
                                                                                        Sachverstandigenburo Priester und Weyde, Saarbr€     ucken,    V    ¼    speed (m/s)
                                                                                        Berlin, 2000.                                                  w    ¼    width of car (m)
                                                                                   [15] J. Priester and M. Weyde, Tests carried out in May 2004,
                                                                                        Eindhoven. CD-ROM, Ingenieur- und Kfz-Sachversta¨
                                                                                        ndigenb€uro Priester und Weyde, Saarbr€ucken, Berlin,         Subscripts
                                                                                        2004.                                                            a ¼ actual
                                                                                   [16] A. Pugsley and M. Macaulay, The large scale crumpling of      car ¼ car
                                                                                        thin cylindrical columns. Qt. J. Mechanics Appl. Math. 13     ccs ¼ collision closing speed
                                                                                        (1) (1960), pp. 19.
                                                                                                                                                       eff ¼ effective
                                                                                   [17] B. Schmidt, CAARS, Reconstruction Specialists, Confer-
                                                                                        ence on Motorcycle Crash Investigation and Reconstruc-        m/c ¼ motorcycle or scooter
                                                                                        tion, Santa Rosa, CA. 2004.                                    oa ¼ overall
                                                                                   [18] J. Searle, The Reconstruction of Speed in Motorcycle Colli-      p ¼ predicted
                                                                                        sions for the Extent of Damage, Road Accident Analysis,          t ¼ total
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                                                                                   Appendix 1.
                                                                                                                                                                                Et ¼ Em=c þ Ecar :                A2
                                                                                   Notation
                                                                                     d ¼ deformation (m)                                              But
                                                                                     E ¼ energy (Nm)                                                                           Ecar ¼ Em=c
                                                                                                                                                                                             dcar
                                                                                                                                                                                                  :               A3
                                                                                     h ¼ offset of the line of action of the motorcycle/                                                     dw
                                                                                           scooter velocity vector (m)
                                                                                     k ¼ radius of gyration (m)                                       Therefore, combining Equations (A2) and (A3):
                                                                                   kph ¼ kilometres per hour
                                                                                      l ¼ length of car (m)                                                                       Em=c ðdw þ dcar Þ
                                                                                    M ¼ mass (kg)                                                                          Et ¼                     :             A4
                                                                                                                                                                                         dw
                                                                                     P ¼ two-tailed p-test value
                                                                                    r2 ¼ coefficient of determination
                                                                                   552                                                          D.P. Wood et al.
                                                                                                                Em=c ðdw þ dcar þ 0:15Þ                                 Et ¼ Mm=c 641:7ðdw þ 0:1Þ0:89 ðdw þ dcar þ 0:15Þ:     A8
                                                                                                         Et ¼                           :          A5
                                                                                                                       dw þ 0:1
                                                                                                                                                                     Combining Equations (A1) and (A8) yields
                                                                                   As                                                                                                                                    12
                                                                                                                                                                                   Mm=c            0:89
                                                                                                                                                                 Vccs   ¼   1283:4      ðdw þ 0:1Þ        ðdw þ dcar þ 0:15Þ :
                                                                                                                                                                                   Moa
                                                                                                                Em=c ¼ SE  Mm=c                   A6
                                                                                                                                                                                                                                A9
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                                                                                                                                               Speed                              Speed
                                                                                   Test                                                        of M/C                             of car
                                                                                   no.             Reference            Motorcycle type        (kph)            Car type          (kph)            Point of contact         Angle
                                                                                                                                                                                                                      (continued)
                                                                                                                                     International Journal of Crashworthiness                                                  553
                                                                                                                                               Speed                         Speed
                                                                                   Test                                                        of M/C                        of car
                                                                                   no.            Reference            Motorcycle type         (kph)            Car type     (kph)               Point of contact             Angle
                                                                                   41     Priester and Weyde 04 [15]   Peugeot Buxy              63      Opel Kadett          0       Right front door                         90
                                                                                   42     Priester and Weyde 04 [15]   Piaggio NRG               30      Opel Kadett          0       Right front wheel                        90
                                                                                   43     Priester and Weyde 04 [15]   Gilera Runner             52      Opel Kadett          0       Left front wheel                         90
                                                                                   44     Priester and Weyde 04 [15]   Sukuki GT 1100            75      Opel Kadett          0       Left front door                          90
                                                                                   45     CTS, test 10402 [5]          Yamaha XZ 550             55.7    Ford Escort III      0       Left side, rear door                     90
                                                                                   46     CTS, test 14613 [8]          Kawasaki GPZ550          110.9    Nissan Sunny         0       Offside front door, near hinge           90
                                                                                   47     Craig [4]                    Yamaha Virago            108.63   Dodge B 100 Van      0       Nearside centre                          90
                                                                                   48     CTS, test 16225 [9]          Yamaha XJ550              88      VW Golf             10       Nearside rear door                       90
                                                                                   49     CTS, test 16226 [10]         Kawasaki GPZ550           87      Saab 9000            8       Nearside front door, near hinge          90
                                                                                   50     Prester and Weyde 08 [20]    Kawasaki GPZ 400          80      VW Polo             15       Nearside rear door                       90
                                                                                   51     CTS, test 11382 [7]          Yamaha XS 750             72      VW Polo              0       Nearside front door centre               80
                                                                                   52     CTS, test 11374 [6]          Yamaha XS 850             72      VW Polo              0       Nearside front door centre              100
                                                                                   53     Searle - CAARS [18]          Not specified             48      Not specified        0       C-pillar/axle                            90
                                                                                   54     Searle - CAARS [18]          Not specified             64      Not specified        0       Driver’s door                            90
                                                                                   55     Searle - CAARS [18]          Not specified             50      Not specified        0       A-pillar                                 90
                                                                                   56     Searle - CAARS [18]          Not specified             74      Not specified        0       Passenger door                           90
                                                                                   57     Searle - CAARS [18]          Not specified             83      Not specified        0       Passenger door                           90
                                                                                   58     Searle - CAARS [18]          Not specified             83      Not specified        0       Side of front fender                     90
                                                                                   59     Searle - CAARS [18]          Not specified             60      Not specified        0       C-pillar                                 90
                                                                                   60     Searle - CAARS [22]          Not specified             74      Not specified        0       A-pillar                                 90
                                                                                   61     Searle - CAARS [18]          Not specified             84      Not specified        0       Side of front fender                     90
                                                                                   62     Searle - CAARS [18]          Not specified             72      Not specified        0       Passenger door                           90
                                                                                   63     Searle - CAARS [18]          Not specified             64      Not specified        0       Rear panel                               90
                                                                                   64     Searle - CAARS [18]          Not specified             72      Not specified        0       Rear door                                90
                                                                                   65     Searle - CAARS [18]          Not specified             56      Not specified        0       Side of front door                       90
                                                                                   66     Searle - CAARS [18]          Not specified             51      Not specified        0       Driver’s door                            90
                                                                                   67     Searle - CAARS [18]          Not specified             61      Not specified        0       B-pillar                                 90
                                                                                   68     Searle - CAARS [18]          Not specified             64      Not specified        0       A-pillar                                 90
                                                                                   69     Searle - CAARS [18]          Not specified            106      Not specified        0       Rear door                                90
                                                                                   70     Searle - CAARS [18]          Not specified             50      Not specified        0       Rear panel                               90
                                                                                   71     Searle - CAARS [18]          Not specified             60      Not specified        0       A-pillar                                 90
                                                                                   72     Searle - CAARS [18]          Not specified             80      Not specified        0       Frontal                                  90
                                                                                   73     Searle - Grandel [18]        Not specified             60      Not specified        0       Front door                               90
                                                                                   74     Searle - Priester 02 [18]    Not specified            100      Not specified        0       Front door                               90
                                                                                   75     Searle - Priester 02 [18]    Not specified             95      Not specified        0       Front door                               90
                                                                                   76     Searle - Priester 02 [18]    Not specified             96      Not specified        0       A-pillar/wheel well                      90
                                                                                   77     Searle - Priester 02 [18]    Not specified             96      Not specified        0       Front wheel/overhang                     90
                                                                                   78     Searle - Priester 02 [18]    Not specified             99      Not specified        0       Front door                               90
                                                                                   79     Searle - Priester 02 [18]    Not specified             97      Not specified        0       Front door/A-pillar                      90
                                                                                   80     Searle - Zilina [18]         Gilera RX 125             39      Opel Rekord          0       Rear impact                              90
                                                                                   81     Bartlett 13 - CAARS 09 [2]   1979 Suzuki GS 550E       73.2    1986 Honda Accord    0       208 cm behind front axle                 90
                                                                                   82     Bartlett 13 - CAARS 09 [2]   1983 Yamaha XJ750M        64.5    1986 Honda Accord    0       43 cm forward of front axle, big         90
                                                                                                                                                                                         rotation
                                                                                   83     Bartlett 13 - CAARS 09 [2] 1983 Honda VT 750C          57.8 1986 Honda Accord        0      137.16 forward of rear axle (near CG)    90
                                                                                                                                                                                                                      (continued)
                                                                                   554                                                              D.P. Wood et al.
                                                                                                                                                   Speed                          Speed
                                                                                   Test                                                            of M/C                         of car
                                                                                   no.            Reference            Motorcycle type             (kph)            Car type      (kph)                Point of contact              Angle
                                                                                   84     Bartlett 13 - CAARS 09 [2] 1981 Kawasaki KZ440D           61.0 1986 Honda Accord          0      Just ahead of RR axle                      90
                                                                                   85     Bartlett 13 - CAARS 09 [2] ‘83 Honda CB550                73.2 1989 VW Golf               0      Just rear of F axle                        90
                                                                                                                        Nighthawk
                                                                                   86     Bartlett 13 - CAARS 09 [2] 1982 Honda CM450C              75.6    1989 VW Golf            0      B-pillar                                   90
                                                                                   87     Bartlett 13 - CAARS 09 [2] 1981 Kawasaki KZ440D           66.5    1989 VW Golf            0      LR axle                                    90
                                                                                   88     Bartlett 13 - CAARS 09 [2] 1980 Kawasaki KZ440 B          86.9    1989 Nissan Maxima      0      43 cm rearward of LR axle                  90
                                                                                   89     Bartlett 13 - CAARS 09 [2] 1986 Suzuki LS650 Savage       88.5    1989 Nissan Maxima      0      86 cm rearward of RF axle                  90
                                                                                   90     Bartlett 13 - CAARS 09 [2] 2004 Kawasaki EX250]F          87.9    1989 Nissan Maxima      0      RR axle                                    90
                                                                                   91     Bartlett 13 - CAARS 09 [2] ‘88 Honda CBR600F Hurr.        90.0    1989 Nissan Maxima      0      96.5 cm forward of RR axle                 90
                                                                                   92     Bartlett 13 - CAARS 09 [2] 1979 Suzuki GS550              90.6    1989 Honda Civic        0      58 cm forward of RR axle                   90
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                                                                                   93     Bartlett 13 - CAARS 09 [2] 1981 Yamaha Seca 750           92.2    1989 Honda Civic        0      left A-pillar, 58 cm rearward of LF        90
                                                                                                                                                                                               axle
                                                                                   94     Bartlett 13 - CAARS 09 [2]   1982 YarL XV920 Virago       90.8    1989 Honda Civic        0      LR axle                                    90
                                                                                   95     Bartlett 13 - CAARS 09 [2]   1990 Kawasaki EX500A         98.0    1992 Mercury Tracer     0      91 cm rear of RF axle                      90
                                                                                   96     Bartlett 13 - CAARS 09 [2]   1982 Si.id GS750             96.2    1992 Mercury Tracer     0      LR axle                                    90
                                                                                   97     Bartlett 13 - CAARS 09 [2]   1980 Sim.id GS750            95.4    1992 Mercury Tracer     0      48 cm rear of RR axle                      90
                                                                                   98     Bartlett 13 - CAARS 09 [2]   ‘86 Suzuki VS700GL           71.3    1986 Mercedes 300E      0      RF axle                                    90
                                                                                                                          Intruder
                                                                                   99     Bartlett 13 - CAARS 09 [2]   ‘85 Honda CB650              77.9 1986 Mercedes 300E         0      99 cm rear of LF axle                      90
                                                                                                                          Nighthawk
                                                                                   100    Bartlett 13 - CAARS 09 [2]   1987 Suzuki GSXR750          76.8    1986 Mercedes 300E      0      30 cm rear of RR axle                      90
                                                                                   101    Bartlett 13 - CAARS 09 [2]   1983 Suzuki GS1100ES         79.0    1986 Mercedes 300E      0      71 cm rear of LR axle                      90
                                                                                   102    Bartlett 13 - CAARS 09 [2]   1978 Honda CB750 H-matic     48.0    1988 Honda Prelude      0      119 cm rear of LF axle                     90
                                                                                   103    Bartlett 13 - CAARS 09 [2]   ‘90 Honda Pac. Cst. PC800    52.9    1988 Honda Prelude      0      RR axle                                    90
                                                                                   104    Bartlett 13 - CAARS 09 [2]   1984 Honda Goldwing 1200     94.6    1988 Honda Prelude      0      89 cm rear of front axle, near F pillar    90
                                                                                   105    Bartlett 13 - CAARS 09 [2]   1978 Suzuki GS1000           97.0    1988 Honda Prelude      0      RR                                         90
                                                                                   106    Craig 12 [3]                 1993 Kawasaki ZX600-C        44.1    2006 Chev. Impala       0      Passenger door                             90
                                                                                   107    Craig 12 [3]                 1978 Honda CX-500            48      2006 Chev. Impala       0      Left rear door                             90
Appendix 4.