TT rin ee UNIT IV TRAFFIC SAFETY AND ENVIRONMENT Road Accidents Street Lighting 4.3. Traffic and Environment Hazards 4.4, Promotion and Integration of Public Transportation 4.5. Promotion of Non-Motorized ‘Transport (NMT)Unit Synopsis Road accidents ~ Causes, effect, prevention, and cost — Street lighting — Air and Noise Pollution, ‘measures — Promotion and integration of ‘public transportation — Promotion of) non-motorized transport Traffic and environment hazards — causes, abatement 4.4. ROAD ACCIDENTS ‘sign and control of the road system, Annual rate of deaths, castaway Steed’s Rule as follows: Annual Road Death, D = 0.0003 (nP)(43) Traffic Engineering and Management| Where, n — Number of Registered Motor Vehicles P — Population 4.1.1. CAUSES OF ACCIDENTS 3 V ‘The major factors involved in the road accidents are as follows: (a) Vehicle (b) Roads and Road Conditions (c) Road Users (d) Road Users other than driver (e) Environmental Factors (f) Other Factors |. Vehicle Vehicle is an important reason for most of the road accidents and the vehicle defects due to the following various reasons: (i) Defects due to lack of maintenance (ii) Failure of important components (a) Failure of Brakes (b) Failure of Headlight (c) Failure of Tyres etc. (@) Steering Defects (e) Low Seating Defects () Other Manufacturing Defects (g) Over loadings etc.(4.3) and Environment the rate of accidents, due to the vehicle defects can easily be controlled by maintenance and replacement of spares etc. However, the sudden ore akdowns (of failure) of important components cause accidents, in most of the be |, Roads and Road Conditions The road characteristics and road conditions are having a great impact on the accidents, The important duty of the Highway Engineer and a Traffic Engineer is to ensure the standards of the road to build the road with correct specifications and to ‘maintain properly. The following factors are considered as the reasons for the road accidents and these factors are to be maintained Properly in order to reduce the accident rates. 1. Poor vertical and horizontal alignment XN Inadequate Sight distances . Super-elevation problems on curves - . Carriageway width Defective Pavements (pots, ruts etc.) Dw . Slippery and Skidding of surface x . Inadequate Shoulders 2 . Improper Road-Junction Designs Ry . Narrow Bridges and Culverts 10. Reduced Width of Medians 1. Deficient Road Signs and Road Markings + Inadequate Highway Lighting - Ribbon Development etc.Traffic Engineering and Managemen Ill. Road Users The various causes of road accidents due to road user’s failure are, (a) Physical Disability (b) Mental and Emotional factors (c) High-Speed temptations (d) Intoxication (e) Disobedience of Traffic Rules and Regulations The driver is the key factor in most of the accidents. The detailed study of driver’s behaviour in road is an essential study, which will help to reduce under control the rate of road accidents. His behaviour influences and controls the vehicle, while behaviour itself is controlled by his personality, training and attitudes. Alcohol and drugs affect his driving capability. The following aspects of a driver influence the road accidents. () Driver's Skill (ii) Age of the drivers (iii) Sex of the drivers (iv) Training of the drivers (v) Alcohol and Drugs consumption during driving (vi) Fatigue, ete. IV. Road Users other than Driver The various persons, other than driver, who may lead to an accident are, | (a) Pedestrians (5) Passengersy and Environment Safety ani traffic {@) Pedestrians Pedestrian characteristics which may cause accidents are, ( Carelessness (i) Mliteracy regarding not knowing of signals (iii) Crossing at places other than. cross-walks Pedestrian’s actions are less Predictable than those o} assume that they can reach the opposite lane before th: isa wrong decision taken by the pedestrians and most the accident situation, f drivers, Many pedestrians © vehicle reaches them. This of the time, this will lead to (0) Passengers The passengers may, © Cause trouble to the driver (8) Make noise, diverti Git) Project their body (i) Getting down the ing the attention of the driver Outside the vehicle vehicle from the wrong side (c) Motor-Cyelists and Scooterists (©) Restriction of Number of Riders (@) Restriction of Speed of the vehicle "Environmental Factors ) Unfavorable Weather Co, @) Rain nditionsTraffic Engineering and Managemen (iii) Summer glare, etc. (iv) Snow, Wind, etc. Vi. Other Factors (i) Animais (ii) Attraction of driver’s attention 4.1.2. CLASSIFICATION OF ACCIDENTS Accidents can be classified as follows: (i) Based on the nature of injury Traffic accidents can be classified based on the nature of injury, are as follows: (a) Little or Small Injury: Minor Injury, not requiring hospital detention. (b) Serious Injury: Injury, requiring hospital detention. (c) Fatal Injury: Resulting in death (i) Based on Collision (a) Collision Accidents 1. Collision with pedestrians | 2. Collision with another motor vehicle fei 3. Collision with a fixed object () Non-Collision Accidents 1. Overturning on the roadway 2. Running off the Roadway 3. Any Other non-collision (iii) Damage-Only Accidents (@) Material Damage (b) Physical Damage beraffic Safety and Environment 40410 190/40 poxy —oj2)y0ns0}0u —suryysopog ym soyrour yy aie oso, 1U0)s 109 woysog uo/s1J02-40N —Aumpvos oy kempeos uo Ho buyjuuny — Guyywinuoag syuopjoay swopjooy oBeweg pe9jshua l uosij09-uoN obeueg ono uosyjo9 Aunfuy Aunfuy Aanfuy soBeweg uosy1o9 Aunfuy jo amen uo poseg uo poseg uo paseg sjuapjooyTraffic Engineering and Management 4.1.3. EFFECTS OF ACCIDENTS Various effects of accidents are grouped as, a) Effects on Individual ©) Effects on National b) Effects on Community a) Individual Effects of Accidents |. Physical Effects Y Death Y Permanent loss of mobility/functioning Y Fractures Y Bruising Y Bums Il. Psychological Effects Y Feelings of guilt Y Post-traumatic stress Y Depression , Y Anxiety/fear Ill. Economic Effects Y Loss of earnings Y Medical bills ¥ Damage to property b) Community Effects of Accidents |. Psychological Effects ¥ Loss of trust Y Loss of family structure-afety and Environment 1. Economic Effects Y Loss of family income Y Loss of community cohesion Y Damage to property ) National Effects of Accidents |. Economic Effects 4 Loss of productivity Y Cost to taxpayers: Medical, legal, increase ‘d insurance premiums, istrative costs, Counselling, Damage to Property 44.4. PREVENTIVE MEASuREs oF ACCIDENTS In order to improve the safe ( Engineering Measures i) Enforcement Measures (iil) Education Measures I Engineering Measures 1. Road Design Efficient and w) Segregation of Traffic A traffic engineering principle of over-riding importance Segregation of traffic ¢ is the ‘ategories by function and in space and time, Example: The segregation of. vehicle and pedestrian of different Classes of Vehicles and of different types and purpose of vehicu! foot paths lar movement, Raiseg for pedestrians. Guara With vertical kerbs should be provided ‘ailing should be installed at hazard erossings.Traffic Engineering and Managemen (ii) Lighting System Visual Observation is marked poorer at night and the driver requires additional reaction and perception time even under good street lighting, Considerable reduction in accident rates can be achieved after the installation of ective street lighting, particularly at intersections, bridges and at other places where there are Tr ictions to traffic movements. ‘Whether a street light should be installed or not can be found out from the following relation. Ic = CAN Where, Ic — The Annual installation cost C — The fractional reduction in accidents expected after the installation of lighting (0.25 to 0.45) N — The average number of injury accident before the installation of| light A.— Average Cost of the injury accident Similarly, a volume warrant for the lighting cost (Ig) 365 Dy V,RCACS Io Where, Dy — Annual Average Daily Volume V,, — The fraction of the annual average daily volume carried at night R — The general night injury accident rate S — The length of the installation On well-lit roads, the vehicles can use the dim dipper lighting syste™- Reflectorized and illuminated signals and street lighting should be wel! maintained, if they are to be effective. (iii) Speed A general expression relating accident rate and speed is given by r = 3.3-0.027S[4.11] Safety and Environment a Where, r — Allinjury accidents per million vehicle km on rural roads S — Mean speed over the length of road in knvhr (iv) Double White Lines and The prohibition to overtake at bends anc id summits can be indicated by double white line marking. Double White Lines may be marke d either on the certain for safe stopping D=123 Vye+ 0.0173 V5, ~ Average speed of the vehicle (in kin/h) (v) Alignment Horizontal alignments lik affect the rate of accid diver, while driving, La distance should be satis! vehicle types, Where, V,., © road width, curvature and si lents because they psycholo, ine width, horizontal and ver factory for the design spec: ight distance highly ically affected the tical curves and sight d, traffic Volumes and (vi) Road Surface Skidding should be avoided as much as possible and Selection of correct asi Toad materials to suit traffic needs is important, — skidding resistance should be Provided, wh ere braking an frequent, Example: At intersections, at curves, Toundabouts on ‘adients ay ; : . approaches to bus stops and pedestrian crossin - High por 7 at : 5 2 ish; Tesistance materials such as Calcined Bauxite ABEregates a Shing locations.Traffic Engineering and Ma (vi) Margins All important roads should have the clear margins, free from vehicles and vertical obstructions such as bridge parapets, piers, y abutments and street furniture such as telegraph posts, street columns. These should be back from the pavement edges by at lez and where, it is not feasible, special precautions in the form of def rails etc., should be taken. Trees must be planted well clear of edges. Obstructions, close to the road margins, decreases the p clearance distances and capacity and causes greater accident pot and severity. (vi) Warning and Control Devices (sequence of raised strips). Jiggle bars may be 10 to 15 mm in hei 50 to 20 rm in width. : ead 10] a impacts on high, suspension and tyres can be damaged and | subsequent failure. Adequate warning signs should be installed to i their existence ahead. Waring homs, bells and light can also be used at dangerous sites but their use is not very common. Il Enforcement Measures (a) Speed Control Tachometers should invariably be installed in the trucks and check the drivers to accelerate their vehicle beyond a cel4.13 fety and Environment traffic Saf vehicles. Find should be imposed and illegal action instituted against those who violate speed limits. (b) Traffic Control Devices Traffic Control Devices, for example, signs, markings, channelizing islands and signals, pedestrian control at turns, parking, pedestrian crosswalks, etc., should be provided for Proper segregation and direction of the traffic. (©) Training and Supervision Strict tests should be conducted for the issue of licenses to the drivers, especially in the case of taxi and heavy commercial vehicle drivers, eee ey Comme;rcial ” Driver’s collection centres for accident repeaters should be set up. (d) Medical Check Drivers should be tested for Vision and reaction time, —iSion and reaction tim at least once in every three years, (©) Helmet Usage Use of crash helmets and seat belts should = LS be made compulsory, Mh, Education ltis Very important that all citizens are tr “sets, The education may be imparted either tules of the road should ‘ained and educated to be good road at home or in the school or in the field. be taught, for example, pedestrians should know the tossing the road, the drivers of Cars, motorcycles, etc., Should be Conversant with the signal system ete, Posters may be exhibited showing the serious Tesults of careless driving. Traffic Safety Week may be on ffic police to impress upon the lms may be shown to the public. ganized by the transport auth ‘orities and the Toad users “Do’s and Don'ts”, DocumentaryTrafic Engineering and Manag (\{(aO STREET UGHTING \ tem is required for the sac and: eff A proper highway: lighting c movenrent of the velicle and pedestrian traffic, throughout the roadway highway lighting, the driver ean see the presence and movements of any objeg (or) adjacent to the roadway, which may be a potential hazard, sunset, Therefore, street lighting has become a Very important part of the work of trafic engineer, 4.2.1. BAsic DEFINITIONS IN HIGHWAY (OR STREET) LIGHTING Mumination Mlumination is the measure of the amount of light flux, which falls o surface and illumination is same if surfaces white or black, It is independent of the following: @ Directions, from which the light comes from Gi) Size and type of the light source Gii) Position of light source (iv) Type of surface Brightness (Luminance) Brightness or Luminance is a measure of the amount and concentration / “ss light flux which leaves some surfaces and it is, by this light that the object ‘seen, Brightness generally depends on the factors that which the illuminationTraffic Safety and Environment independent and listed above. Brightness is the opposite of illumination and it is to It te noted that where the illumination is highest, the brightness may be minimum and vice versa. Lumen Lumen is the unit of luminous flux radiated and equal to the amount of flux received on an area of one square metre and is the same as that on the surface of a sphere having an intensity of one candle power placed at its centre. Metre Candle Meter Candle is the normal incident illumination produced by the unit candle Power at a distance of one meter. Night Vision In order to locate an object on the road, it is essential that, there is sufficient Contrast of colour between the object and its background (or) the difference between the parts of the object. The principal method of discernment is by, @ Silhouette (6) Reverse-Silhouette (c) Surface Detail (@) Discernment by Shadow () Discernment by glint ®) Sithouette When a unit object on the roadway Is a saihouett. darker than the background discernment is by Sil ‘iscerned, due to the object appears (b) Reverse-silhouette When the object is brighter Reverse silhouette. than its background, discernment is given by anTraffic Engineering and Managemen) (c) Discernment by Surface details = Where the variations in brightness and colour of the object’s surface, without regard to its background, contrast help in discernment, it is called discernment by surface details. (d) Discernment by Shadow The presence and the movement of an object is inferred from its shadow. | (e) Discernment by glint The objects (or) details of the object are being perceived through specular 1 reflection of light from some of its polished surface. ility Bak The night visibility depends on the following factors. Factors affecting Night Visi (@) Size, Colour and Brightness of the object (b) Brightness of the Background (c) Light reflecting characteristics of the road surface (@ Driver's Eye Glare (e) Time available to see the object. 4.2.2, FACTORS AFFECTING THE STREET LIGHTING Following factors affect the efficiency of the Street lighting: GB + Distibution of Light 2. Position of Posts ee 3. Types of Power of sources 4, Spacing of lamps 5. Overhang 6. Avoidance of glare 2. Mounting height etc.ic Safety and Environment trafic Safer 2.3. LIGHT DISTRIBUTION ON THE CARRIAGEWAY Ado The source of light should have the Proper distribution of light, in order to frighten the entire road surface. It is very difficult to have a uniform distribution of sit throughout the carriageway at a distance, but a fair distribution of light can aways be obtained. The light source should be located in such a way produces the maximum uniformity of Pavement bri; distributions are used to distribute the light in various 1, Two-way Lateral Distribution that, it ightness, Following luminaire situations. Type-l Distribution is also called as Two-W; suitable for narrow roads, This system is shown 2 ‘ay Lateral Distribution and it is in figure 4.1.(a) Narrow-Asymmetrical Lateral Distribution Type-Il_ Distribution is also called as Narrow-, Asymmetrical Lateral Distribution and it is also suitable for narrow toads. The distribution of light Of this system is shown in figure 4.1.(b). Narrow-Width-Asymmetrical Lateral Distribution Type-IT Distribution is also known as’ Medium Width Asymmetrica} Lateral Distribution and suitable (©) explains the distribution of light. Wide. for roads with medium Width. Figure 4.1. > -Asymmetrical Lateral Distribution Type-IV Distribution is also termed as Wide Asymmetrical Distribution and it is Suitable for wide ro: Width as shown in figure 4.1. (d) Lateral ads and highway with the larger a Normal-Symmetrical Distribution Type-V Distribution is also known as Ne lormal-Symmetrical Distribution and itis suitable for placing at the centre of the hi; ighways and at intersections, This System can be explained in figure 4.1. (c)Traffic Engineering and Managemen Fig. 4.1.(a) Two-Way Lateral (Type-I) Distribution 90° 180° 90° 25° 0° Fig. 4.1. (b) Narrow-Asymmetrical Lateral (Type-I) Distribution 90° 180° 90° o Fig. 4.1. (d) Wide Asymmetrical Lateral (Type-IV) Distributiony and Environment Safety am afc 180° ‘90° 90° o Fig. 4.1. (¢) Normal Symmetrical (Type-V) Distribution The bright area in the road depends on the following factors: 1. Reflection Properties of the toad Distribution of Light Power of the Lamp Height of the Light Source Height of the observer surface ' ae Fen Distance of the observer from the Light Source 4.2.4, Position oF Posts The distribution Post and there an 1 of light and visibility of object highly depends on the location four system of location of. the light posts. + Opposite Arrangement 2 Staggered Arrangement 3. One-Side Arrangement a 4. Central Arrangement \ Opposite Arrangement Figure 4.2. shows the arrangement of highway lights. In this arrangement, the lights = ar Just opposite to each other on either side of the road, In this S¥stem the road is well-defined and is suitable for roads with the larger widths,Fig. 4.2. Opposite Arrangement 2. Staggered Arrangement either side of the road. This arrangement is not suitable for the roads with curves. This arrangement is shown in figure 4.3. Fig. 4.3. Staggered Arrangement 3. One Side Arrangement (Single Side Arrangement) Figure 4.4, shows the single side arrangement of lighting layout. In this arrangement, the highway lights are located at an equal interval only on an} side of the road. This arrangement is adopted for narrow streets, Fig. 44. One Side Arrangement 4. Central Arrangementjervand Environment Road ——ae= Median Vig. 4.5. Central Arrangement Mm provi ides an effective lighting at less cost because of luminaire supports and electrical conductor saving in - It gives the impression of continuous well lighted road without any obstruction, ‘The disadvantage of this systentis that the foot paths and cycle paths remain comparatively dark, 4.2.5, TYPES AND THE Power oF Sources Theroad lighting lamps ate of following major four types 1. Tungsten Filament lamps 2. Sodium Vapour lamps 3. Tubular FI uorescent lamps. 4, High-Pressure Mereury-Fluorescent lamps The choice of different types of lamps, its size and colour of the lamp depends onthe following two factors, ® Spacing of Lamps (i) Distribution of tight flux The tungsten. lamps have low initial co: “Tsieney and life is low. ‘The fluorescent lamp ing to the drivers. It has a good durabilit Reva, But the number of la Utpat per lamp. st. At the same time, its lighting Provides visibility and itis the Least and relatively high lighting " ly lative! y high lighting Power} imps required for a fixed length is high due to the low High pressure mercury lamp light has a bluish white colour which makes the ‘Oundings more pleasing to the eye and the low of the sodium vapour lamp,1. Spacing of Lamps It is better to provide the closer spacing of lights, because it gives bette, brightness. The spacing of light depends on the importance of the road. mounting heights with high power-output lighting units. 35 m to 55 m for good visibility and suitable for all types of roads. Il, Mounting Height height is applied for important urban roads. Itis important from the following two points of view (a) The distribution of light point of view (b) The glare point of view From the law of Inverse-Squares, the intensity of illumination produced by light from a small source varies inversely as the square of the distance from the source, By this, greater mounting heights give a better light distribution and if the ih is mounted at lowest height, the light rays reach the driver’s eyes directly 28 ashe approaches it and may lead to accidents. . a Ml. Overhang Al the kerb and will produce the long shadows of the moving traffic. The problem Traffic Engincering and Managemen) The spacing between the lamps on the sprite roads is about 3 to 5 times of the] mounting height of the lamp. The spacing for sharp curves, is closer for better visibility conditions. The spacing between Jamps can be increased, by using higher Experiments prove that spacing between the lighting units may vary from ‘The Mounting height plays an important role in deciding the design of layout of] | If the lamp is provided just above the kerb, the light will be more effective 9") r highway lighting. Generally the mounting height varies from 6 m to 10 m and 10m] a more i ii i i z Predominant in the case of roads with the lights only on one side, #5)Mounting height Ree Length of shadow | 4.6. (b) Overhang in Highway Lighting 426, AVOIDANCE OF GLARE Fig. Slave is defined as the disturbi ing influence when viewing a difficult visual task nder low brightness conditions.Traffic Engineering and Manageme] Glare may be produced in different ways, but the effect of each one is to Teduce the visibility. Glare has two important effects on the vehicle and road users, (i) Discomfort (ii) Blinding Effects The amount of glare is negligible, if the mounting height is about 9 m, jf increases sharply with reduced mounting heights. The relative blinding effect from a light, mounted a height of 3 m is, 13 times more than the blinding effect from a light mounted the height of 9 m and above, Followi Wo types of glare have a critical influence on the visual performance ofa driver. (a) Disability (or Physiological) Glare (6) Discomfort (or Psychological) Glare (a) Disability (or Physiological) Glare This glare occurs from stray light, which reduces contrast sensitivity and thus producing a loss of visual efficiency. It can be reduced by increasing the mounting height and increasing background brightness, (b) Discomfort (or Psychological) Glare It occurs due to the ocular discomfort from a bright light source. It can be minimized by reducing the brightness of the light, increasing the mounting height and by increasing the background brightness, From the above, for any type of glare, the mounting height of a lighting unit is an essential factor to reduce the glare. 4.2.7, ARRANGEMENT OF LAMPS AT JUNCTIONS t is something different that the arrangement of lamps in a junction from the} | arrangement of lamps in a straight path.Trae Safety and Environment The following figures show the Arrangement of lamps in various road junctions, Fig. 4.7. Lamp Arrangement in a Junction Not more than Fig. 4.8. Lamp Arrangement in a Square JunctionAbout 3/4S About 3/4S Fig. 4.9, Lamp Arrangement in *Y? Junctionsafety and Environment in TP? Jun ction of Pedestrian Crossing ees I I 1 1 | ) of tod Fig. 4.11. Lamp Arrangement in Square Junction of Pedestrian Crossing ‘28, SPACING OF LAMPS AND LATERAL PLACEMENT The spacing between the lamps can be determined by the following relation, i ilization x Maintenance Factor Spaci, Lamp lumen x Co-efficient of Utilizat Pacing = =Smp lumen x Coefficient of Vilzation x Maintenance Factor Average Flux x Width of the road © maintenance factor is generally taken as a aa echatien of ‘tlization can be calculated by using co-efficient of utilization chart as given in Neto da,Co-efficient of Utilization ong a 6 Width Mounting Height Fig. 4.12. Co-efficient of Utilization Chart Lateral Placement As per IRC recommendation, the street light posts should be installed at the following horizontal clearance from the pavement edge. (a) Roads with raised kerbs: 0.3 mo 0.6 m. (6) Roads without raised kerbs : 1.5 m from the edge of the carriageway .3. TRAFFIC AND ENVIRONMENT HAZARDS Following are the hazardous effects of traffic on the environment. v Safety i Noise i Air Pollution Vibration Visual intrusion and Degradation of Aesthetics ooh oe Severance 4.3.1, Noise Noise is defined as an unwanted sound, Traffic Noise is an important outdoot noise. If the noise is created from the nearby streets, it is called as outdoor noise)” and the largest source of outdoor noise is generally the automobile traffic on roads. automobile traffic on 10°Frafe Safety and Environment 4.29 ‘The increasing_urbanization in cities and growth of automobiles increase the ¢ NN OF automobiles Jume of noise. Noise in cities is created by vol Y Toad traffic, aircraft, railways and industrial and constructional works, LEffect of Noise Y Subjective Effects Y Behaviour Effects x Physiological Effects The following table 4.1 shows the various effects of noise on humans, Table 4.1, Various Effects of noise on humans a No| Noise Level oe _ (in aBy ( 1. lb Threshold of Audibitit 2, 80 Annoyance 3 90 Hearing Damage 4. [95 High Annoyance 5. 110 Stimulation of reception in Skin 6. 120 Pain Threshold 2. 130-135 Nausea, Vomitin; 8. 140 Pain in Ears 9. 150 Burning of Skin 10. 160 Minor Damage Start 1, Major Permanent DamageThe intensity of noise produced by the traffic is depending on the following factors, v eS 4. Wind effects a Traffic Engineering and Managemen | | | Type of the traffic Volume of the traffic . Distance of the traffic 5. Other disturbances The following points are to be considered in the traffic noise. Noise levels produced by different types of trafti 1, A petrol car produces lesser noise than the diesel jeep. 2. In general, a new automobile produces lesser noise than the old-poorly maintained vehicles. 3. A propeller type aircraft produces lesser noise than a jet type aircraft. 4. Appetrol car produces lesser noise than the diesel jeep or truck. 5. An electric train produces lesser noise than the diesel and steam locomotives, a ic are given in the following table. Table 42. Noise levels produced by different types of traffic Sl ise lev Sourees of noise Nols lre No ) (in dB) | Air traffic 1. | 1. Jet aircraft at take off stage at about 300 m 100-110 2. Propeller aircraft at take off stage at about 300 m 90 - 100 - 2.__| Rail Traffic (at about 30 m) 90-110- 3._| Heavy road traffic (Highway) 80-90- (4. _| Medium road traffic (Main Streets) 70-80 Light road traffic (Side Streets) 60-70 6Traffic Safety and Environment = ir 4) Subjective Effects (ai) Subjective Effects of noise are Caused by various noise level described in the above table, and various symptoms are disturbances, dissatisfaction, annoyance and discomfortness, b) Behaviour Effects longer time to fall off to sleep Noise can cause interfer programmes, It can cause disturbances jn studi considerable distraction Can result in the student’ 'S mind due to Continuous high level of traffic noise. The efficiency i activity can be impaired by noise, 9) Physiological Effects U Acceptable Noise Levels Noise levels are very high in all places especially in big cities nowadays due to the tremendous increase in automobiles and vehicles. In order to prevent the Problems due to excessive noise, Government of India - Unlog Environment Ministry recommended that the noise standards for diferent kinds of vehicles, as Pie ary follows, 1. Two wheelers - 80 dB 2 Cars “82 dB i icles 3 Passenger and commercial vehic!Traffic Engineering and Mana; (a) Upto4MT- 85 4B (6) Between 4m to 12 MT- 89dB (©) More than 12 MT - 91 dB The owners of the vehicles will have to secure the certificates that their vehi will meet the prescribed noise pollution norms. Ill. Control of Traffic Noise reated by the traffic can be controlled by the following ways. The noise c1 Y Changing the Design of Vehicle Changing the Tyres or Road Surfaces Removal of Noiser Vehicles Modification in Traffic Operation Designing strects for less noise production Y Green belt Development a) Changing the Design of Vehicle for the Govt. to frame rules to control the noise created by automobiles. Changing the Tyres or Road Surfaces while designing.get and Environment gemoval of Noiser Vehicles i) ld vehicles can produce higher noises and hence, older and noiser vehicles an be replaced by a newer one to reduce the noise pollution. « ) Modification in Traffic Operation By doing the following modification in traffi ic operation, the noise can be reduced. Re-routing the commercial vehicles and lorries away from the important residential areas, Prohibiting blowing horns by proper signing and enforcement measures, Providing bye Passes and Ring roads Providing synchronized traffic signals at crossings Designing Streets, Buildings for less noise Production > a situation commonly known as Canyon Effect. ‘When Planning new Streets, it is desirable to plan for wider streets, A Tequirement is the hei Telated developed, ‘ght of buildings and environmental standards has been Sreen Belt Development Green belts teduce the effect of noise pollution and are Very good absorbers of noise especially of high frequencies, ‘urban areas, the vegetation belt with appropriate height and width can t ‘orb acoustic energy, by transferring ‘sed for noise reduction. Plant leaves abs the kinetic energy of vibrating air molec ule in a sound field to th Pattern of the leaves. ie Vibration,4.34 4.3.2. AIR POLLUTION increase the air pollution. The exhaust fumes from the automobiles cause pollution of atmospheric air in cities. Air pollution created by the automobiles is] _ called as disease of wealth. |. Major Pollutants The following are the important pollutants causing 90% of the global air pollution. Y Sulphur-di-Oxides (SO2 etc.) Carbon Monoxide, CO Carbon di-oxides "Oxides of Nitrogen (NO, NO,, generally NOX) Lead Compounds Water Vapour il ¥ v ¥ Hydrocarbons (HC) and Organic Compounds v v a Smoke Particles Il. Effects of Air Pollution a) Effects of SO, man-made sources, causes very serious effects on human beings, 1. It increases the breathing rate and creates the 02 deficiency in blood ——_ : : —__* circulation. 2, Asthma patients are affected very worst due to this pollutant.Traffic Safety: and Environment ») Effects of Carbon monoxide Carbon monoxide has a Sreater blood-affinity property and which has been fected by blood haemoglobin 200 times more than O2. This CO, replaces the O2 present in the haemoglobin ‘and forms Carboxy-haemoglobin, (CO.Hb). If the quantity of Carboxy-haemoglobin is less, then it produces the little headache, ‘eduction in reaction time etc. on human beings. If the quantity of CO.Hb concentration is high, it creates difficulty in breathing, heart problems ete. Also, if COHb.quantity is about 50% of Hb, it makes death of human being. Other harmful effects of CO are, 1. Cardio-Vascular diseases (due to the reduction of 02 in ti ssues). 2. Visual perception, Manual dexterity, Mental disability 3. Creates headaches ¢) Effects of Nitrogen Oxides NO, is a harmful gas, which irritates the human eyes and nose and creates ciscomfort in respiration system. 1. Formation of ozone 2. NO, creates the irritation in nose and lungs. 3. Increases the possibility for viral attacks. 4) Effects of Carbon-Dioxide (CO2) 1. Climatic changes + 1 2. Global warming 7 3. Green house effect/~ ®) Effects of Lead 1. Mental retardation 2. Behavioural disorders3. Increases blood pressure 4, Heart diseases Ill. Control of Air Pollution Following are the some of the air pollution control methods caused by automobiles, 1, Replacement of burning fuel by electricity or solar energy. Replacement of old machineries with the new one. By installing mechanical air pollution controlling devices. 3 Installations of three ways in all automobiles to reduce-the concentration of emissions. By reducing the use of vehicles either by resorting to public trans D switching over from vehicles to other means such as cycling or wall king manufacturer, turning the engine off on red light and paying attention to the overall maintenance of the vehicle 4 ee is also an option to reduce the poll a level = a Resort to alternative energy sources, like solar power and wind pow whenever possible. : Following are some of the measures that can be adopted for air pollution control : 7 a) Green belt development Implementation of the En b) Implementation of the Enforcement and Regulations c) Traffic control d) Prohibition of volatile fuels usage etc. e) Usage of smokeless fuels 4.3.3. VIBRATION When a vehicle is moving on a road surface, vibrations are created. These are grouped as, 4 1. Surface Vibrationsty and Environment rate Safety 2. Underground Vibrations 3. Vibrations in the surrounding air, preventive Measures Following are the some of the P; wavehicle moving on a road surfai v Teventive measures taken against vibrations due ce, Improving the surface finish of the road Providing high width or streets Enforcing the minimum distance between the buildings Reducing the highly vibrated motors in the restricted zones SNS Improving the suspension system of the motor vehicle. 4.3.4, VISUAL, INTRUSION AND DEGRADATION OF AESTHETICS tis possible to safeguas rd the Surroundings from the ill effect by collaborative planning amongst traffi ‘The needs of traffic and the buildings 1 idered, The Visual ileffects of parking can be got aver by decides Parking and enforcing regulations for on-street parking, Itis possible to control unsi; ighty bill boards by suitable regulative Some of the tecommended meas Measures, ures are, Y Acquisition of adequate right-of-way Y Control of Access Y Construction of bypasses around congested cities Y Provision of parallel service roads to meet the needs of local traffic v Prevention and removal of encroachments. 4.3.5, SEVERANCE AND LAND CONSUMPTION Severance is the psychological, cultural and “affic facility. When compared with other count physical disturbances created by in India are at low level. tries, the traffic Problem Condit; ionsTraffic Engineering and Manag 4.4. PROMOTION AND INTEGRATION OF PUBLIC TRANSPORTA’ In order to overcome the problem created by motor traffic, public transpo: ‘ies are encouraged. In Indian cities, the in buses or mass transit rail faciliti reated problems of congestion, accidents, increase in Car ownership has cI and pollution. Yi trips on buses, trains and minibuses etc. Bus-fransport has many advantages that it can carry a lot people for the space it occupies. By using public buses, the fuel consumption will highl reduced and thus the air pollution. Public transport is labour intensive and « ‘can j —_—_—_— ———_____ provide jobs for unemployed. In India, the Central_Government_have been| providing loan assistance to the local authorities fo. augmenting and strength alte i the public transport. An efficient public transport can be done only after proper planning the selection of bus routes must be based on detailed travel surveys. The| routes should be as far as practical direct respect to Origins and Destinations of| passengers. The bus stops and routes should be planned that the walking distance of the passengers from the place of residence to the bus stop should not normally be high. (Say 0.5 km to 1.0 km or involving not more than 5 to 10 minutes walking). The frequency of service is not an important consideration. The buses 4 themselves must be built and maintained for comfort and safety. The entry and exit e ways should be designed carefully and emergency exit ways must be installed. Larger and comfortable seats with windows increase the pleasure of the trp. For i the convenience of standing passengers, hand holds must be in adequate quantity: — I Int adequate qua Na4.39 Fie Safety and Environment trafic at street must be planned for bus traffic and bus stops are to be located ‘The les Ghana nient and safe places. Bus shelters of good design to protect the passengers aver as cal Tight and heat of sun and rain, 0 ee Exclusive bus lanes have been tried at a number of cities to speed up bus ‘ransport. In congested localities, mini-buses are schemed, ‘ample, a structure which favours long distance tip-makers will facilitate the dispersal of tesidences, while at the same time twork. increasing the load on the existing ne Modes, is extremely popular even in metropolitan cities, TyPes of IPT vehicles in India 1. Cycle Rickshaw - Speed is about 10 kmph 2. Motor Cycle Rickshaw ~ Speed is about 15 kmph 3. Three wheeler Auto Rickshaw - Speed is about 25 kmph 4. Six Seated Auto Rickshaw —- Six persons can be Stated, excluding driver S, Matador Van Diesel operated with 8 or 15 Seating capacity,\.. Advantages of IPT Vehicles 1, Less fuel consumption Greater maneuverability in congested streets Point to Point service capacity Lowest cost Provision of job for the weaker sections of the society, j These modes oo both recreation tion and transportation, and are eps i important for short travels up to 10 kms, which take up the largest share of tipsia 4 urban areas. It can be stimulated by a policy package consisting of investments i facilities, awareness campaigns, sma art urban planning, improved public and disincentives for the use of motorised private vehicles. Specific ways to improve non-motorised transportation are, v Public bicycle systems (automated bicycle rental systems designed provide efficient mobility for short, utilitarian urban trips) Develop ) pedestrian vorented lend sea and building design. shortcuts Traffic calmingfic Safety and Environment ri Streetscape improvements Congestion Pricing Vehicle Parking Policies —_—_ ain policies Fuel taxes 4 SA'S oe — < . on many Country-specific fact culture, H © climate, 8eography, > Political commitment ublic awareness, polic: Y effort a Sonsistency, long-term vision and the attractiveness of the alternatives and most of these facto; awe pene ee The main barriers towards implementing a Successful NMT Policy are, sport Planning Public Perception and Status: Walking, is perceived as the transportation mode f Private Vehicle Oriented tran: . cycling (ang Public. rt) for the poor. The Ticher part of the population often has a disproportionate decision Power, whi ch Makes : d policy risky. NMT-focuse policy . Safety: Pedestrians and particularly cyclist are -Yulnerable, and need separate road Space, or at least be resp. ected and taken Vehicle users. Lack of social safety, especially for females barrier, therefore Note of by £20 also beaLack of convenient public transport, which is required to make NMTq| good option for multi-modal trip (ie. the combination of cycling rapid bus or rail systems). Chicken-and-Egg problem: cycle lanes, cycling. Lack of overall long-term, integrated vision and planning. People don’t start cycling if there are fe and planners don’t build these when there is no interes High costs for bicycles, including taxes. 4.5.3. STATUS AND FUTURE MARKET POTENTIAL OF NMT taking pl: ing place, there may be opportunities to choose a Jower-carbon path developed countries have done. 4.5.4. BENEFITS OF NMT Good walking and cycling opportunities are a key part of any st i : transport and planning strategy, and provide an overall improvement of the 4 of life. In addition to this, the Environmental benefits of NMT are, @e Air quality improvement @* Emission reduction Non-motorized transport does not emit greenhouse gas emissions, oFTrafic Safety and Environment The Social benefits of NMT are, ¢ Congestion reduction rn ¢ Health benefits due to exercise, For example, cycling for 30 minutes a eee day reduces the chance of cardiovascular diseases and diabetes by 50% ¢ Gender benefits: Cycling can be particularly suitable for the many short trips women in developing countries take social equality and ¢ Poverty reduction: Cheap, fast and reliable transport opportunities and ee ers public space development directed towards all segments of society. * Safety: Increase in bicycle use is often accom anied by a reduction in iP My cycling accidents and an increase in safety in public areas, ¢ Noise reduction The Economic benefits of NMT are, . NMI, particularly cycling is easy flexible, cheap and fast © More attractive cities for tourists and residents, Particularly if car-free Sd zones are included : © Reduced travel times due to improved traffic flow © Energy security due to lower vehicle energy use. ~Traffic Engineering and Manag 44 arate two or more traffic strea zi ds are used to sep: Y Channelizing Islan ed to divert the traffic into defini intersections, the channelization is us' travel paths. Y-Aroundabout (or a rotary) are special islands provided for the protection of| is a specialized form of at-grade intersection, Y Loading Islands / i passengers and pedestrians located at regular bus stop (or) train stoppin, highway. F , Y Conflicts are classified as Crossing, Diverging and Managing Conflicts. the intersecting streets. v If the angle of intersection departs significantly (approximately more 20°) from right angles, the intersection is called Skewed Intersection. called a refuge area. ¥ Road junctions (or) Intersections are the areas in the highway, at which tv or more roads meet (or) cross each other at the same (or) different levels. Y The intersections are to be provided with Proper signal system with propet separation and control of the traffic, § Y The type and design of road condition. Junction can be selected based on the oie F Itis desirable to avoid change of gradient at the road intersections. Y The design is mainly base le two fi ind Efficienc; ly based on the two factors, j y i net TS. i.¢., Safety ai iciel v i i Intersection (or) Crossing of roads in the same level is called at oe intersection and this is the common type of. intersection. Y Channelized Intersections or simy the intersection and areas and the ply achieved by introducing islands int®) {otal conflict area will be reduced.Trafic Safety and Environment rac Safer Y The channels are to be constructed about 200 mm higher than the road level no additional pavement Provided and these are the most economical Y Plain intersections are the intersections, in which width for turning movement is form of intersections, ¥ Flared intersections are the i roadways at the Junction p width, intersections in which the widths of intersecting oints are higher than the ordinary carriageway ‘ary is an enlarged road inter Converging vehicles are forced to move round the large o direction (clockwise direction), section where all entral island in one Y Grade Separated Intersections are also called flyover junction. In this Srengement, there is no physical connection between the separated roadways in a grade separation, Y The interchange is used to indicate a grade Separation having facility for traffic to pass from one intersecting Toad to the other, v Half cloverleaf interchanges are located when a major road crosses e a minor road (of less than 3 lanes) Y Roundabout (or) a rotary is a specialized enlarged intersection, in which Vehicles from various lanes are forced to Move around a large central i ie + 5 4 . : in clockwise direction, a A totary (traffic) island is located in the centre of the intersection to & the movement in a clockwise direction and thus substitute Weaving of t i : i : iF ; tray around the island instead of direct crossing of vehicle Pathways, e Weaving is the combined movement of a merging and diverging of tp fj - . + + S Streams moving in the same direction, 7 Weaving length is defined as the length of a section of a rotary in which . IC] Weaving occurs, v The shape and Position of the rota ry island depends on as number and the direction of int Various fact ors, Such fersecting roads and traffic flow Pattern,Traffic Engineering and Manogene] The different types of rotary are circular, elliptical, turbine type and the tangent type etc. The selection of shape of the rotary is based on the number of traffic lanes and the intersecting angle between the roads Circular Road trees are adopted in most of the intersections. The IRC has recommended that the design speed of 40 km/h for rotaries in tural areas and about 30 km/h (generally 32 km/h) for rotaries in urban and the restricted areas. In general, Radius of Curve at exit is 1.5 to 20 times the radius of curve at entry. Radius of the curve at exit_= 1.5 to 2_ x Radius of the curve at entrance In curves of a rotary at the exit point, P Centrifugal Ratio, W 7 0:2 100.4 Radius of Central Island is kept larger than the radius of curve at the entrance. Radius of Central Island = 1.33 x Radius of the curve at entrance The entry and should be 60°, if possible. The exit angle should be less than the entry angle and even tangential. Weaving angle is measured along the centre of the one-way road between the noses of the channelizing islands The width of the varriageway at entrance and exit of a rotary is governed by the movement of traffic entering and leaving the rotary. At the edge of the control island, one light post per island should be provided. An additional lighting arrangement may be provided for circular islands having diameter more than 60 m.: 447 traffic Safety and Environment TWO MARKS QUESTIONS AND ANSWERS j. What are the various causes of accidents? (Nov /Dec 2014) Y Vehicle Roads and Road Conditions Road Users Road Users other than driver Environmental Factors Other Factors =~ 5 Ss SS 2. How pedestrian cause road accidents? Pedestrian characteristics which may cause accidents are, Y Carelessness v Illiteracy regarding not knowing of signals Y Crossing at Places other than cross-walks Classify the accidents based on injury, Y Little or Smalt Injury: Minor Injury, not Tequiring hospital d, Y Serious Injury: Injury, requiting hospital detention, Fatal Injury: Resulting in death etention. What are the major effects of accidents? Y Effects on Individual Y Effects onNational Y Effects onCommunity Differentiate between the “silhonette and reverse silhouette” in Street "ghting. (May /June 2013) When a unit object on the roadway is discemed, due to the object appears 'e. When the object is brighter than its background, discernment is given by Reverse silhouette, darker than the background discernment is by SilhouettTraffic Engineering and Managemen State the factors affecting night visibility. The night visibility depends on the following factors. Y Size, Colour and Brightness of the object v Brightness of the Background Y Light reflecting characteristics of the road surface Y Driver’s Eye Glare ¥ Time available to see the object 7. Draw the sketch for lamp arrangement in ‘Y’ junction, with salient features, 8 How the glare is reduced? Y By increasing the mounting height and increasing background brightness. Y By reducing the brightness of the light, increasing the mounting height and by increasing the background brightness 9. How the spacing between the lamps is determined? The spacing between the lamps on the sprite roads is about 3 to 5 times of the mounting height of the lamp. Experiments prove that spacing between the lighting units may vary {0 35 m to 55 m for good visibility. The spacing between the lamps ca0 b¢ determined by the following relation.Frafe Safety and Environment ZS ing = Lamp lumen xCo-efficient of Utilization Maintenance Factor Spacing = Average Flux x Width of the road The maintenance factor is Generally taken a: utilization can be calculated by using co-effic suitable for all types of roads, Ss 0.8 and the co-efficient of ient of utilization chart y and 10, What are the different metho, 1S by which street light arrangeme done? (Nov Dec 2011) nt can be e Opposite Arrangement 2. Staggered Arrangement 3. One-Side Arrangement 4. Central Arrangement (Nov Dec 2012) Me Distribution of Light Y Position of Posts : Types of Power of sources Me Overhang Avoidance of glare ¥\ Mounting height etc, 12. What is meant by “Speed Change Lanes "?(Now/Dec 2015) Deceleration ane Fig. Acceleration-Deceleration LanesTraffic Engineering and Manager 4.50 13. If. 2: 4. 5. r acceleration and deceleration of vehicles ing lanes are provi In inflared intersections, fo (or leaving) to the traffic, these lanes are called Decel shown in the above figure. What is IPT? Intermediate Public Transport (IPT) is a sub set of pul 1 and deals with low technology vehicles that occupy less space and provide for an additional speed chang eration (or Acceleration) lanes. These iblic transportation | short distance travel. What are the Advantages of IPT Vehicles? Y Less fuel consumption Greater manoeuvrability in congested streets Point to Point service capacity Lowest cost Provision of job for the weaker sections of the society. REVIEW QUESTIONS. Write briefly the different factors cause accidents in traffic enginee! in ICRC standards. (Nov/Dec 2012) Refer Article 4.1.1. Page 4.2 Explain the effects of. accidents, in detail. Refer Article 4.1.3, Page 4.8 Refer Article 4.2.3, Page 4.17 What are the effects of air pollution Refer Article 4.3.2, (1) Page 4.34 State the benefits of NMT. Refer Article 4.5.4, Page 4,42 caused by various transports? LCR