TTE 5204 TEST #1 NAME kb-?RRRx QQFf?

jr~pKL~J
SPRING '03 (75 minutes)
Essarn Radwan Exam Date is Februarv 11,2003

Read the follow in^ instructions:

Students are allowed to .use one single sheet (8.5~11inches) as a cheat sheet and they
may use both sides. No other material is admitted except a regular pocket
calculator. FEEDS students that are taking this test off-campus should follow the
same rules, and may take this test no later than 5:00 pm, Friday February 14.
Problem #1 (50 Points) 9
Select the phrase that correctly completes the following statements.

1. When designing a crest vertical curve for desirable stopping sight distance, if the
assumed value of the driver's eye height is reduced, the length of the curve will:

d. Insufficient data given to complete the statement

2. The braking distance of an automobile is a function of:

a. Vehicle speed
b. The coefficient of friction between the vehicle tires and the roadway
c. None of the above
g / ~ l of
l the above

3. If the space mean speed of a traffic sample is 50 mph, and the traffic stream density is
48 vpm, the flow rate is:

a. 48 vph
b. 800 vph
,p' 2400 vph
d. None of the above

4. From the information in part 3 above, the average vehicle headway is:

a. 2.5 sec.
b. 5.0 sec.
c . 1 sec.
&sec.
5. The speed at which 15% of the drivers travel at speeds higher than this speed is called:

a. m e 15th percentile
e minimum speed
85th percentile
d. The median speed

6 . If 8,000 vehicles pass a point during a 4-hour period, the average daily traffic is:

a. 48,000 vpd
b. 32,000 vpd

>.8:2:8nt data given to answer

7. Theoretically speaking, for a pretimed traffic signal, when the cycle length increases
the intersection overall capacity will:

Acreme
b. Remain the same
c. Decrease
d. Insufficient data given to answer

8. Speed data on highways usually fit:

a. Bernoulli Distribution
b. Radwan Distribution
egative Exponential Distribution
Distribution

9. Studies have shown that peripheral vision is a critical factor in drivers:

of speed
eeing better at nigh6
of sign shapes
d. None of the above.

10. Traffic composition of a two-lane road in a mountainous terrain has a significant

impact on:

a. The facility capacity

ap distribution on the road

d. None of the above

 11. For roadways with uninterrupted flow conditions, the peak hour factor is defined as:

a. The ratio of the peak hour traffic volume to four times the highest 5-minute

of the highest 15-minute volume to the peak hour traffic volume

c. The ratio of the peak hour traffic volume to 12 times the highest 15-minute
volume
@) None of the above
12. The 30th highest hourly volume has been suggested as:

he design hourly volume for rural facilities

'I.
The Peak-Hour volume for urban facilities
c. ')?he capacity for rural facilities
d. None of the above

13. Pavement super-elevation is provided on horizontal curves at high-speed facilities

primarily to:

a. Provide better drainage

Prevent vehicles from losing control
better friction between road surface and tires

14. The field of peripheral vision for most drivers extends around the centerline of the eye
at a range of:

a. 3 to 5 degrees
b. 10 to 12degrees
/ 120 to 180 degrees
d. None of the above

15. The capacity of a two-lane rural road is around:

a. -2,000vph per lane

b. 1,800 vph per lane
$/2,800 vph total both directions
d. None of the above

16. The capacity of a one lane freeway is around:

k 1,000 pcph
6b. 2,200 pcph
 >;::: $e;: above

17. The capacity of a one lane of through traffic without parking at a signalized
intersection is around:

1,600 pcph
,000 pcph

18. The capacity of a two-lane rural road is around:

e. 2,000 vph per lane

2 ,800 vph per lane

2,800 vph total both directions
h. None of the above

19. The Chi-Square statistical test is used to:

a. Test the equality of mean of two distributions

(h Test the equality of variance of two distributions

b& a
Q _ ~ ~ e sthe
t skewness of a statistical distribution
None of the above

20. Flex-time is used by employers to:

&y educe the annual VMT in the region

Reduce the average trip length
lncreke highway capacity
None of the above

21. For freeway operation, the peak of the speed-flow and density-flow relationships that
typically describe its operation (usually parabolic) is:

a. The maximum possible speed

y he jam density
The maximum possible flow (capacity)
d. None of the above

22. The moving vehicle method is applied to record the following data:

a. Traffic volumes
b. Travel times
 Speed
All of the above

23. The AASHTO recommended brake reaction time is:

c. 3.5 seconds
d. None of the above

24. The recommended deceleration rate to determine the amber period (clearance
3-
duration) at a signalized intersection is: ,ofl\et\ \ vc

a. 15.0 feet per second square

b. 20 feet per second square
c. 18 feet per second square
Y ~ o n ofethe above

25. The k Factor (Proportion of daily traffic occurring during the eak hour expressed as a
decimal) for an urban area is: \ p a q -\d"f C@ U L b@

yk 0.12-0.15
d. None of the above
 Problem #2 (20 Points) 13
A two-mile section of a rural, two-lane, two-way highway has a posted speed of 45 mph.
The Traffic Engineer in-charge of this highway is interested in studying the speed
characteristics of vehicles using this section of highway. A spot speed study was
conducted at a location where traffic flow was thought to be characteristics of the entire
two-mile section. The Traffic Engineer started tabulating the statistics of this study,
however, he stopped short of completing the whole process. The following is the
frequency table.

Group Middle (v) Frequency (f) % Freq. % cumul. (f)(v) (f)(v)(v)

32-34 33 I 0.51 0.51 33 1089
34-36 35 4 2.04 2.55 140 4900
36-38 37 8 4.08 6.63 296 10952
38-40 39 14 7.14 13.78 546 21294
40-42 41 22 t\.@ 2a-.* 902 36982
42-44 43 29 14.80 39.80 1247 53621
44-46 45 33 16.84 56.63 1485 66825
46-48 47 3I 15.82 72.45 ia~? 68479
48-50 49 21 10.71 83.16 1029 50421
50-52 51 15 7.65 90.82 765 340l55
52-54 53 9 4.59 95.41 477 25281
54-56 55 4 2.04 97.45 220 12100
56-58 57 3 1.53 98.98 171 9747
58-60 59 2 1.02 100 , 118 6962
Total 196 100 8886 407668,

You are asked to:

1. Fill in the four blank cells in the table above

- .

2. Calculate the arithmetic mean

3. Calculate the sample Variance

 % Freq.

Show on the above graphs:

1. Median Speed

( 2. 8sthpercentile speed
/ J #"?
3. Mode ,:wh

4. IOMPHPace ,e\
Problem #3 (20 Points) f
A traffic engineer is attempting to learn whether there are speed differences associated
with different days of the week for the same spot location. One set of data obtained for a
typical week indicates that a sample of 21 speeds obtained on a Wednesday had a mean
value of 32.0 MPH k d a variance of 26.9. A second sample of 27 speeds taken Friday,
indicated a mean value of 36.7 MPH and a variance of 29.1. If it is assumed that the
speeds are sampled fiom normal populations with the s k e variance, are the populations
equal at the 5 percent level of significance?' ,

The Cumulative Normal Distribution Table values are:

 /
Problem #4 (10 Points) 5
A four-legged intersection controlled by a pretimed traffic signal has been observed to
have the following parameters:

Saturation headway = 2.0 seconds ( h 3

Lost time per start = Lost time per stop = 2 seconds
Cycle length = 60 seconds
Signal Split = 50-50
Peak Hour demand per . .lane = 900 vehicles per hour

a. Calculate the capacity per lane

1
- Cop85 [(a,, -- ?+JA&&@ &%J\-
[g&,
(

m f (ma 2 F ?BOV~R~&/~

b. The average number of vehicles that do not clear the intersection during the green
period
 TTE 5204 TEST #1
SPRING '02 (75 minutes)
Essam Radwan

Read the follow in^ instructions:

Students are allowed to use one single sheet (8.5~11inches) as a cheat sheet and they
may use both sides. No other material is admitted except a regular pocket
calculator. FEEDS students that are taking this test off-campus should follow the
n same rules, and may take this test no later than 5:00 pm, Wednesday February 13.

Problem # l (20 Points)

List Only d-wdy

1. Two main benefits of deploying ITS technologies //23 e- $h~beuJi-JQk&=-

C - E-
2. Three

3. Four major variables that influence the safe stopping sight distance ~1

4. Three performance measured for access management

5. Three main factors that affects drivers' perception-reaction time

6 . Three applications of AASHTO design vehicles and their dimensions

,
7. Two important federal or state programs that influence traffic safety
 Problem #2 (20 points)

Explain Why

1. Statistical distributions and testing of hypotheses are commonly used in traffic

engineering

2. One lane capacity on a two lane rural road is much smaller than one lane capacity on a
freeway

bp 4%"??as$ pr NO- p a ~ < ' = p , m

& k~
aLaW
, .--rds3,-&-
<
""3
iYUhdm% -4-a t D s k w Q $

3. The 30th highest hourly volume has been suggested as the design hourly volume for

%s++d P1*hhq4+.
4. Space mean speed and density are negatively correlated

5. The 10 mph pace has been used in speed studies as a reliable safety measure on

6. Although statistics showed that the number of deaths on US highways has increased
steadily over the last 50 years, the deaths rate per 100,000,000 vehicles-miles decreased.

-tR, ~ ~ S ~ f Y w d A&
4 L L l 4
7. Ramp metering is used on freeways

8. Flex working hours help with reducing road congestion

9. Crash cushons are used in gore areas

10. Truck traffic reduces road capacity

.
.

b+'-(*w )upoue*(4A&,,
Problem #3 (20 Points)
Select the phrase that correctly completes the following statements.

1. If the space mean speed of a traffic sample is 40 mph, and the flow rate is 2,000 vph,
the traffic stream density is:

@SO vpm
b. 800vpm A
c. 500 vpm
d. None of the above
2. From the information in part 1 above, the average vehicle headway is:

a. 2.5 sec.

C
d. 0.50 sec.

3. The speed at which 15% of the drivers travel at speeds higher than this speed is called:

a. The 15 th percentile
b. The minimum speed
Q ~ h 85e th percentile C
d. The median speed

4. If 8,000 vehicles pass a point during a 4-hour period, what is the average daily traffic:

a. 48,000 vpd
b. 32,000 vpd
3
(5 2n:z;nt data ,en to answer

5. Theoretically speaking, for a pretimed traffic signal, when the cycle length increases
the intersection overall capacity will:

Qincrease A
b. remain the same
c. decrease
d. Insufficient data given to answer

6. Speed data on highways usually fit:

a. Bernoulli Distribution
b. Radwan Distribution
3
c. Negative Exponential Distribution
@normal Distribution
 7. The field of peripheral vision for most people extends around the center of the eye at a
range of:
a. 3 to 5 degrees.
b. 10 to 12 degrees.
Q120 to 180 degrees.
d. None of the above.
C
8. The Speed at which half of all the vehicles travel faster than this speed and the other
half travel slower is called:

a. The mode speed..

b. The minimum speed.
@ The median Speed. C
d. The 85thpercentile speed.

> 9. The sensation that gets affected most for a drunk driver is:

3
stimulus.
L'
10. Saturation flow rate at signalized intersections is the maximum flow rate achieved
when:
/ a. Signal is green for few seconds and queue exists.
Signal is red and queue exists.
Signal is green for a long period and queue exists.
3
Signal is green for a long period and no queue exists.
Problem #4 (20 Points)

A large rock became visible to a driver on a horizontal curve at a distance of 300 feet.
Assuming a perception-reaction time of 2.0 seconds, an initial speed of 50 mph, a
coefficient of hction equal to 0.50, and a level roadway, calculate the speed at impact.

Given that the curve radius is 350 feet, and the curve was not superelevated, what is the
coefficient of side hction the vehicle encountered at the initial speed? Is that high?
 Problem #5 (10 Points)

'@
3400 vph
4aD

600 vph 300 v p h ? ~ ~ Ba *ph 400%

44m
3m~*
'fm 4515 *Q@* 330

>

The capacity of the five sections are provided as following:

Section #1 Section #2 Section #3 Section #4 Section #5

4400 vph 3800 vph 3400 vph 4400 vph 4400 vph

Is there a bottleneck at this freeway section?

'!% c4- 3 4 - s,3b~
Redo calculations if the capacity of section 2 and 3 were improved to 4400 vph.
Problem #6 (10 Points)

A line of vehicles at a signalized intersection begins to move with the initiation of the
green signal. If the time to clear the first five cars was recorded to be 11.0 seconds, and
the time needed to clear the first nine cars was recorded to be 18.6 seconds, determine:

1. Saturation headway (Sh)

2. Lost time per start. (1)

Extra Information:
J
SSD = 1.47Vot+ v2130(f+or - g)

v, = Sum(v)ln

v, = L I Sum(t)

R=5730/D

T, = n S h + 1

Where:

T, = Time to clear the nth vehicle