Traffic Engineering-MODULE-1 vtu syllabus.pptx

Traffic Engineering-MODULE-1

1. TRAFFIC ENGINEERING

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5. MODULE 1 Traffic Planning and Characteristics: Road Characteristics-Road user characteristics, PIEV theory, Vehicle Performance characteristics, Fundamentals of Traffic Flow, Urban Traffic problems in India, Integrated planning of town, country, regional and all urban infrastructures, Sustainable approach- land use & transport and modal integration.

6. The Hindu Hrudaysamrat Balasaheb Thackeray Maharashtra Samruddhi Mahamarg

7. Expansion of infrastructure is important to accelerate the process of overall development of the country. The contribution of this, in the journey of Maharashtra to date, is huge. To speed up the development process, the state government is planning to connect Nagpur and Mumbai with a length of 701 km. The Hindu Hrudaysamrat Balasaheb Thackeray Maharashtra Samruddhi Mahamarg is an ambitious project of the people of the state as well as the government.

8. " Samruddhi Mahamarg Package-13 Progress _ Nagpur Mumbai Expressway Phase-3 Update.mp4"

9. R ole of T r anspo r t a t i on Transportation c o nt r i bu t e s to the Economic , Industrial , Socia l and Cultural development of any country. The adequacy of transportation system of a country indicates its economic and social development. 5

10. Di f f e r ent modes of t r anspo r t a t i on The f o ur m o d e s o f t r ansp o r t a t i o n are R oadw a ys or Highways Railways iii. W a t e r w a ys i v. A ir w ays 6

11. Scop e of Highw a y Eng i neer i ng T r ansp o r t a t i o n e ng i n e e ri n g c an be b r o a d l y c o ns i st i ng of the four major topics: 1. T r a n sp o r ta t i o n P l a n n i ng 2. G eo m e tr i c D e s i gn 3. P a v e m e nt D e s i gn 4. T r a f fic Engi n ee r i n g 7

12. T r anspo r t a t i on Pl a nning A ct i o n p l a n f o r the d e s i g n. C o nst r uct i o n a nd o p e r a t i o n of transportation facilities. C urr e nt a s w e ll a s future transportation system. 8

13. Geom e tr i c Des i gn C r o ss se c t i o nal fea t u r e s . Horizontal alignment. V e r t i c al a l i gnm e nt and intersection. 9

14. P a v em e nt Desi g n S t r uc t u r al d e sign o f roads. D e si g n o f p a v i ng materials. De t e r m i nat i o n o f l a y e r thickness. C o nst r u c t i o n and maintenance. 10

15. T r a f fic Eng i neer i ng Application of scientific principles, tools, techniques for Safe, Rapid and Economic Movement of people and goods. Objectives of traffic engineering is to achieve Efficient, Free and Rapid flow of traffic with least n u mber o f acci d en t . 11

16. Objectives of Traffic Engineering The basic objective of traffic engineering is to achieve efficient, free and rapid flow of traffic with least number o f t r a f fic a c ciden t s . To study the operational characteristics of highway transportation. To study the need for better geometric design, capacity, intersections, traffic regulations, signals, traffic signs, roadway markings, parking facilities, design of bus stands and truck terminals, street lighting etc. 12

17. Scop e of T r a f fic E ngin e ering The study of traffic engineering is divided into seven major sections T r a f fic c ha r a c te r istics T r a f fic st u d i e s and a nal y sis T r a f fic o p e r a ti o n T r a f fic plan n i n g and anal y sis Geom e tric design A d m i n ist r a ti o n and M an a ge m ent 13

18. Functions of Traffic Engineer Collection, Analysis and Interpretation of data pe r t a i n i ng to t r a f fi c. T r a f fi c and T r ansp o r t a t i on p l an n i n g . T r a f fi c des i g n . T r a f fi c mea s u r e s . Administration 14

19. T R AF F IC CHAR A C T E R IS T I C S 15 Traffic characteristics involves the study of road user characteristics and vehicular characteristics Road user characteristics : The factors which affect r o ad u s e r c ha r a c t e rist i c s are Physical Mental Psychological Environmental

20. 1. P h ysic a l cha r ac t eris t ics: 16 It may be either permanent or temporary. The permanent physical characteristics are the vision, hearing, strength and general reaction to traffic situations. Temporary physical characteristics of the road users affecting their efficiency are fatigue, alcohol or drugs and illness. Vision : Hearing: P I EV Th e o r y :

21. Visi o n: Visual The test is a standard chart-reading exercise that measures static visual acuity - that is, the ability to see small stationary details clearly. 17

22. PI E V Th e o r y : 18 The re a c ti o n t i m e o f the dr i v e r i s the t i me t aken f r om the instant the object is visible to the driver to the i n s tant t h e b r ak e s a r e e f f ect i v ely app l ie d . The stopping distance increases with increase in reaction time of the driver. The psychological characteristics of road user concerns Perception , Intellection , Emotion , and Volition . The time taken for these processes is known as PIEV time.

23. PI E V Th e o r y : Perception time: It is the time required for the sensations received by the eyes or ears to be transmitted to the brain a nd s p i n a l c ho r d . It through the nervous system is the time required to perceive an object or situation. I n t e l l e c t i on t i m e : I t i s the t i m e required for understanding the situation. 19

24. PI E V Th e o r y : Emo t i on t i m e : I t i s t he t i me elapsed s e nsa t i o ns d uri n g and e m o t i o n a l di st u r b a nc e s su c h a s f e a r , a n g e r o r a n y e m o tion a l g o v e r ns the f e e li n g s d e c i s i o n other which m a ki n g p r o c e ss o f an individual. V o l i t i on t i m e : I t i s t he t i m e taken for the final action . 20

25. 2. Men t al cha r ac t eris t ic s : Kn o wl e d g e , sk i l l , intelligence, experience and literacy can affect r o ad us e r c ha r a c t e ris t i c s . Understanding the traffic regulation, i nst r u c ti o ns a n d s p e c ial t i m e l y a c t i o n d e p e nds on intelligence and literacy. 21

26. 3. Ps y cholog i cal f ac t ors : Some road users do not pay due regard to the traffic regulations and do not have right attitude towards the traffic. The reaction of a road user (PIEV time) to traffic situation affects to a great extent. Th e e m otional a ttenti v ene s s , f actors s u c h as f e a r , a n g e r , impatience, general attitude towards traffic & regulations and maturity also come under psychological factors. Distractions by non-traffic events and worries reduce attentiveness to traffic situations. 22

27. 4. Environment a l f ac t ors : The factors which affect the road user under this are traffic stream, traffic facilities, atmospheric conditions and the locality. Th e adap t ab ilit y to d i f f e r e nt t r a ff ic stream characteristics depends on the driver's characteristics as well a s the m oti v a t io n . The weather, visibility etc are the env i r on m ental f acto r s . The locality may be shopping centre or a place with other distractions to the road user, thus affecting their behaviour. 23

28. VEHI C ULAR C HAR A C T E R IS T I C S 24 Th e y are i) St a t i c c h a r ac t eris t i cs ii ) D ynamic c h a r ac t eris t i c s .

29. i) S t a t i c cha r ac t eris t ics: 25 Static characteristics of vehicles affecting road design are the dimensions, weight and power of a vehicle. The height of the vehicle, height of driver seat, height of head light, clearance below the chassis, length of vehicle, turning radius all these affects the design of overtaking sight distance, curves, humps, sight distance etc. The gross weight, axle load and wheel loads of vehicle govern the structural design of pavements and c r o ss d r a i na g e st r uc t u r e s .

30. a. V eh i cle d i mensions V eh i c l e dime n s io n s a r e the o v e r all length, width and height of different vehicles. The width of vehicle affects the width of traffic lane, shoulders and parking facilities, capacity of the road etc. Height of the vehicle affects the clearance to be provided under bridges, electric lines etc. Length of vehicle affects the design of horizontal curves, extra widening of pavement, turning radius, overtaking distance and parking facilities.  26

31. b . W e i ght of v eh i cl e : This affects the design of pavement thickness and gradients. As per IRC the axle load should n o t e x c ee d 1 t o n s . The gross weight of the v e h icl e i n k g s i s g i v e n by W = 1525(L+7.3) – 14.7 L 2 where L ( in mts) = distance between the extreme axles.  27

32. c. P o wer of v eh i cle The power performance of vehicle determines the g r a d i e nt o n r o a d s . F o r the v e h i c l e to mo v e at desired speed, the following forces have to be overcome. Rolling resistance, Air Grade and I n e r t i a resista n c e , resistance force. 28

33. i i ) Dyn am i c cha r ac t eris t ics Dynamic characteristics of vehicles effecting road design are Speed Acceleration Breaking characteristics. 29

34. a. Spee d of v eh i cl e : The design speed controls most of the geometric features of highways. Th e s p eed of v ehi c le s e f f ects Sight di s ta n c e Supe r ele v a tion L ength of t r an s itio n c u r v e R ad iu s of ho r izo n ta l c u r v e Wi d th of pa v ement & s ho u ld e r s Gradient Design of intersection, traffic c ont r ol m ea s ures et c . 30

35. b . Acc e l e r a t i on 31

36. c. B r a k ing cha r ac t eris t ics The stopping distance, spacing between two consecutive vehicles in a traffic stream are affected by the braking capacity, highway capacity and overtaking sight distance are also get effected. Braking tests are conducted to measure the skid resistance of the road at the desired running speed. B r ak i n g di s t ance i s gi v e n b y , where d=braking distance, V = s p e e d i n k m ph  f=coefficient of friction between tyre & pavement 32

37. Fun d a m ental pa r a m et e rs of t r a ffi c flow T r a ffi c St r eam P a r am e t e r s Speed v=(d/t) in m/sec. Spo t Speed R unn i ng Speed J ou r n e y Speed T i m e M ean Speed and Sp a c e M ean Speed 33

38. F l o w . Th e n the fl o w q e x pres s e d i n v e h i c l e s/h o ur i s g i v e n b y q =nt/ t F l o w i s e x pres s e d i n p l ann i ng and d e sign fi e l d tak i ng a d a y as the m e asu r e m e nt o f time.  34

39. T ypes of V olume Me a su r em e nts A v e r a ge A n n ual D a ily T r a ffi c (AADT) A v e r a ge A n n ual W eek d ay T r a ffi c (AAWT) A v e r a ge D a ily T r a ffi c ( A D T A v e r a ge W ee k day T r a ffi c ( A W T ) 35

40. Density Density is defined as the number of vehicles occupying a given length of highway or lane and is generally expressed as vehicles per km/mile.  36

41. Deri v ed cha r ac t eris t ics 37 From the fundamental traffic flow characteristics like flow, density, and speed, a few other parameters of traffic flow can be derived. Significant among them are the time headway, distance headway and t r a v e l t i m e . Th e y are d i scus s e d o ne b y o ne b e l o w .

42. 38 Time he a dw a y The microscopic character related to volume is the time headway or simply headway. Time headway is defined as the time difference between any two successive vehicles when they cross a given point.  D ista nce he a dw ay Distance headway Another related parameter is the distance headway. It is defined as the distance between corresponding points of two successive vehicles at any given time.  T r a v el tim e Travel time is defined as the time taken to complete a journey.

43. T i m e - space di a g r am T i m e s p a ce dia g r am i s a c o n v e n i e n t t oo l i n un d e r s t a n d i n g t h e m o v e m e n t o f v e h ic l e s . I t s h o w s t h e t r a j e c t o r y o f v e h ic l e s i n t h e f o r m o f a t w o d i m e n s i o n a l p l o t . T i m e s pa ce dia g r am can be pl o tt e d f o r a s i n gle vehicle as well as multiple vehicles. T h e y a r e d iscus s e d b e l o w . S i ng l e v e h i c l e Taking one vehicle at a time, analysis can be ca r r i e d o u t o n t h e p o s i t i o n o f t h e v e h ic l e w i t h r e s p e ct t o t i m e . T h i s a n aly s is will generate a graph which gives the relation of its position on a road stretch relative to time. 39

44. Miu l t i ple V eh i cl e s Time-space diagram can also be used to d e t e r m in e t h e fundamental parameters of traffic flow like speed, density and volume. It can also be used to find the derived characteristics like space headway and time headway. 40

45. G r eenshie l d ’ s m a c ros c o p ic s tr eam model 41 Macroscopic stream models represent how the behaviour of one parameter of traffic flow changes with respect to another. Most important among them is the relation between speed and density. The first and most simple relation between them is proposed by Greenshield. Greenshield assumed a linear speed-density relationship as illustrated in figure 33:1 to derive the model. The equation for this re l at i o n s h i p i s s h o wn b e l o w .

46. 42 Where v i s the m e an spe e d at d e n s i ty k , vf i s the fr e e sp e e d and kj i s the j am d e nsi t y . Th i s e qua t i o n i s o ften r e fer r e d to as the Greenshields’ model. It indicates that when density b e c o m e s z e r o , sp e e d a pp r o a c h e s fr e e fl o w s p e e d ( i e . v → v f wh e n k → 0).

47. R el a t i on between speed and de n s i ty 43

48. R e l a t i on be twe e n speed and fl o w 44

49. R el a t i on between fl o w and de n s i ty 45

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