Advance transportation engineering

1. F-29, Omaxe City, Phase-II, Jaipur 302026
ADVANCE TRANSPORTATION ENGINEERING
(7CE6.1A)
PREPARED BY
MR. SUNIL KUMAR
(ASST. PROFESSOR)
CIVIL DEPARTMENT

2. 2
Traffic Studies

3. UNIT – IV
BLOWN UP
RTU SYLLABUS BLOWN UP TOPICS
Elementary Traffic
Engineering: Significance
of different Traffic
Engineering Studies viz.
Speed, Volume, O & D,
Accident’s and Parking
Study. Importance and
types of Traffic Signs,
Signals, Road Markings
and Road Intersections.
4.0 Important Definitions
4.1.Traffic Engineering Studies
4.1.1 Traffic Speed Studies
4.1.1.1 Significance of Spot Speed
4.1.1.2 Method of recording spot speed
4.1.2 Traffic Volume Study
4.1.2.1 Significance of Traffic Volume Studies
4.1.2.2 Traffic Volume Counting
4.1.2.3 Presentation of Traffic Volume Data
4.1.3 Origin and Destination Studies
4.1.3.1 Significance of Origin and Destination Studies
4.1.3.2 Application of O&D Studies
4.1.3.3 Method of data collection of O&D studies
4.1.3.4 Presentation of O&D data
4.1.4 Accidental Studies
4.1.4.1 Significance of Accidental Studies
4.1.4.2 Causes of Accidents
4.1.4.3 Accidental Studies and Records
4.1.5.Parking Studies
4.1.5.1 Definitions
4.1.5.2 Types of Parking Surveys
4.1.5.3 Common Method of On-Street Parking
3

4. BLOWN UP
BLOWN UP TOPICS
4.1.6 Traffic Control Device
4.1.6.1 Traffic Sign
4.1.6.2 Traffic Signal
4.1.6.2.1 Importance of Traffic Signals
4.1.6.2.2 Types of Traffic Signal
4.1.6.3 Road Marking
4.1.6.3.1 Classification of Road Marking
Conclusion
RTU Questions
4

5. 4.0 Important Definitions
Spot Speed
Instantaneous speed of a vehicle at specified section or location is termed as spot speed.
Time Mean Speed
Average speed of vehicle in at a certain road length at any time.
Running Speed
Average speed maintained by a vehicle over a particular stretch of road.
Overall Speed or Travel Speed
Effective speed with while a vehicle transverse a particular route between two
terminals.
Traffic Volume
Traffic volume is the number of vehicles crossing a section of road per unit time at a
selected period.
Origin and Destination
Origin is the starting point of any trip and destination is the end point of trip after its
travelling complete.
Traffic Sign
It is a mechanisms which is used by the traffic engineer to communicate with the road
users.
5

6. Desire Line
These lines are straight lines used in data presentation, connecting origin points with
destination. The width of line are proportional to the number of trips on both direction.
Parking Volume
The number of vehicles parking in a particular area over a given period of time. The
unit of parking volume is vehicle per day.
Parking Duration
The time spent in a parking space by vehicle.
Parking Index
The percentage of parking bays actually occupied by parked vehicles as compared to
the theoretical number available.
Parking Turnover
The rate of usage of the available parking space is called parking turnover.
No passing zones
No passing zones are established on summit curves, horizontal curves, and on two lane
and three lane highways where overtaking maneuvers are prohibited because of low
sight distance. 6

7. 4.1 Traffic Engineering Studies
4.1.1 Traffic Speed Studies
Traffic speed varies with geometric features traffic condition, time place, environment
and driver.
(a) Spot Speed
Instantaneous speed of a vehicle at specified section or location is termed as spot speed.
The spot speed can be measured by two ways
 Space Mean Speed
 Time Mean Speed
Space Mean Speed
Average speed of vehicle in at a certain road length at any time.
Where, Vs = Space mean speed (km/h)
d = road length (m)
n = no. of individual observed vehicle
t1 = observed travel time (sec) for the ith vehicle to travel distance (m)

 n
i
t
dn
Vs
1 1
6
.
3
7

8. Time Mean Speed
Average speed of vehicle in at a certain road length at any time.
Where, Vt = Time mean speed (km/h)
vi = observed instantaneous speed of ith vehicle (km/h)
n = no. of observed vehicle
(b) Running Speed
Average speed maintained by a vehicle over a particular stretch of road.
(c) Overall Speed or Travel Speed
Effective speed with while a vehicle transverse a particular route between two
terminals.
n
v
Vt
n
i i

 1
stopping
and
delays
all
including
time
Total
vehicle
by
travelled
ce
dis
Total
speed
Overall
tan

Time
ce
Dis
Speed
Running
tan

8

9. 4.1.1.1 Significance of Spot Speed
 It is useful in planning, traffic control and traffic regulations.
 It is useful in geometric design of road.
 It is useful in accidental studies.
 It is used to study the traffic capacity.
 The spot speed is affected by physical features of roads like pavement width, curve,
sight distance, gradient, pavement unevenness condition, intersections and road side
developments.
 Other factors; environmental condition like weather, traffic condition, driver, vehicle
and motion of vehicle.
4.1.1.2 Method of recording spot speed
 The spot speed is recorded by “Enoscope”.
 The enoscope is a mirror box, supported on a tripod stand.
 The observed stand is fixed at a point and enoscope is kept a certain distance of
about 30m; so that the observer can easily see the mirror image of vehicle on
emoscope.
 When the vehicle passes through the point observed stopwatch start and when it
passed the enoscope stopwatch get stopped.
9

10. 4.1.2 Traffic Volume Study
Introduction
Traffic volume is the number of vehicles crossing a section of road per unit time at a
selected period. Unit of measurement vehicle per day or vehicle per hour. The traffic
volume survey deals with recording of traffic data. It includes,
 The various types and classes of traffic
 The distribution of traffic by direction
 Turning movements of traffic
 The distribution of traffic on different lanes per unit time.
Fig: Principle of Enoscope
10

11. 4.1.2.1 Significance of Traffic Volume Studies:
 It gives relative importance of the roads and helps to decide the priority for
importance and expansion.
 It is useful for planning, traffic operation and controlling of existing facilities.
 It is useful to analyze traffic pattern and trends.
 Useful to plan one-way street or other regulatory measures.
 Turning measurement study is useful for design of intersection, in signal timing,
channelization and other control.
 Pedestrian traffic volume study is useful for planning side works, cross works, sub
 ways and pedestrian signal.
4.1.2.2 Traffic Volume Counting
Traffic volume can be counting by two ways:
1. Mechanical Counting
2. Manual Counts
1. Mechanical Counting
These may be fixed or portable type. They can automatically record the total number of
vehicle crossing a section of the road in a desired period. They can record the impulses
or stimuli, caused by traffic movements. It can work for 24 hours.
11

12. 2. Manual Counts
A field team made to record the traffic volume on the prescribed sheets. It is possible to
record vehicle classification, turning movements, loading condition etc. It is usually
difficult to count 24 hours.
4.1.2.3 Presentation of Traffic Volume Data
Annual Average Daily Traffic (AADT)
It helps to decide the relative importance of a rout and in phasing the road development
program.
Trend Charts
The volume trend over period of years are
prepared. They can show data for planning,
future expansion, design and regulation.
Variation Chart
It shows hourly daily and seasonal variations.
They help to decide facilities and regulations
during peak traffic hours.
30th Highest hourly volume or design hourly
volume
It is a plot between hourly volume and the
numbers of hours in a year in which traffic
volume exceeded.
Fig: Traffic Flow Diagram at
Intersection
12

13. 4.1.3 Origin and Destination Studies
Introduction
The origin and destination (O&D) survey determines the directional distribution of
traffic in an area.
4.1.3.1 Significance of Origin and Destination Studies
• It provides the plan for road network and other facilities for vehicular traffic.
• It provides the plan of schedules for different modes of transportation for the trip
demand.
• The O&D studies of vehicular traffic determines their number, their origin and
destination in each zone.
• These data also give the number of passengers in each vehicle, purpose of trip, and
intermediates stops made etc.
• The O&D studies can give information like actual direction of travel, route section
and trip length.
• These studies are most essential in planning new highway facilities and improving
the existing system.
• The O&D study provides the basic data determining the desired directions of flow or
the desire lines.
13

14. 4.1.3.2 Application of O&D Studies
• To plan transportation system and mass transit facilities in cities including route and
schedule of operation.
• To locate expressway or major route along the desired lines.
• To locate new bridge as per traffic demand.
• To locate intermediate stops of public transport.
• To establish design standard for the road, bridge and culverts along the route.
• To locate the terminal and plan terminal facilities.
4.1.3.3 Method of data collection of O&D studies
a) Road side interview
b) License plate method
c) Return post card methods
d) Tag on car method
e) Home interview method
a) Road Side Interview
• The vehicles are stopped at preciously decided interview station.
• They are ask a set of questions by some persons.
• The collected information included ; route, location of stoppages, the trip purpose,
vehicle type and passenger number in each vehicle.
• The percentage of sample out of the total traffic in each selected period should also
be noted from appropriate traffic volume study taken simultaneously.
14

15. b) License Plate Method
• The Study area is identified and the observer are present at all points of entry and
exit on all the route.
• Each observer party is given synchronized time places and they note the license plate
numbers (registration number).
• Separate recording sheets are maintained for each direction of movement for a
specified time interval.
c) Return Post Card Method
• A questionnaire is printed on a prepaid business reply post cards with return address.
• This method is suitable traffic is heavy.
d) Tag on Car Method
• In this method, a pre-coded card is stuck on the vehicle as it enters the area under
study.
• When the car leaves the identified area other observations are the recorded on the
tag.
e) Home Interview Method
• A random sample of 0.5 to 10% of the population is selected and detailed
information are collected by residents.
• The collected data is useful for planning the transportation requirements of the
passengers.
15

16. 4.1.3.4 Presentation of O&D data
The O&D data may be present by any of following method:
Origin and Destination Table
These are prepared showing the number of trips between different zones.
Desire Line
These line are plotted which is a graphical representation.
These lines are straight lines connecting origin points with destination.
The width of line are proportional to the number of trips on both direction.
Counter Line
The shape of the counter lines indicates the general traffic need of the area.
Pie Chart
To find the relationship between generated traffic and geometrical relationship, pie
chart are drawn.
Fig: Desire line Plan Fig: Contour Line Map
16

17. 4.1.4 Accidental Studies
4.1.4.1 Significance of Accidental Studies
1. To study the causes of accidents and to suggest corrective treatment.
2. To evaluate existing design.
3. To support proposed design.
4.1.4.2 Causes of Accidents
• Driver-Speed, carelessness, violation of rules and regulations, sleep, alcohol.
• Pedestrian
• Passengers
• Vehicle defects
• Road design
• Weather
• Road condition
• Animals
4.1.4.3 Accidental Studies and Records
a) Collection of accidental data
• General data
Date, time, person, involved in the accidents, classification of accidents like fatal,
serious, minors etc.
• Location
• Detail of vehicle involved
• Nature of accidents
17

18. • Road and Traffic Condition
Detail of road geometrics, surface condition, dry, wet or slippery.
• Primary causes of accidents
• Accidental Cost
b) Accidental report
The accident should be reported to the police authorities who would take legal action.
c) Accident Record
Location Files
Files are useful to keep a check on the location of accidents and to identify points of
high accidents.
Spot Maps
Accident location can shown by spots, pins or symbols on the map having scale 1in
4000 to 1 in 6000.
Condition Diagram
Drawing to scale showing all important physical conditions of an accident location
studies e.g. curves, kerbs lines, bridge etc.
Collision Diagram
It shows the approximate path of vehicles and pedestrian involved in the accidents.
18

19. 4.1.5.Parking Studies
4.1.5.1 Definitions
Parking survey conducted to collect the required information about the capacity and use
of existing parking facilities. In addition, information about the demand for parking is
needed.
a) Parking Volume
The number of vehicles parking in a particular area over a given period of time. The
unit of parking volume is vehicle per day.
b) Parking Duration
The time spent in a parking space by vehicle.
c) Parking Index
The percentage of parking bays actually occupied by parked vehicles as compared to
the theoretical number available.
d) Parking Turnover
The rate of usage of the available parking space is called parking turnover.
100
.
.
x
available
bays
of
no
l
Theoritica
occupied
bays
of
No
Index
Parking 
19

20. 4.1.5.2 Types of Parking Surveys
 Parking Space Inventory
 Parking Usage survey by petrol
 Questionnaire Type Parking
(a) Parking Space Inventory
The first step is to collect data on the, location of actually available space. Then the
area is identified usually is the surrounding the Control Business District (CBM) is
placed. Then this area is sub divided on a street by street basic and these are marked on
a map.
(b) Parking Usage Survey by Petrol
This type of survey includes counts of parked vehicle at regular intervals through a
period covering morning and evening peak hours, parking accumulation and turnover.
In this method, a map is prepared for indentified street system. The recording is carried
out on the both direction on the road.
(c) Questionnaire Type Parking
This type of survey include direct question to parking users or shopkeepers near the
parking area. 20

21. 4.1.5.3 Common Method of On-Street Parking
Parallel Parking
It consumes maximum curb length which deceases as the angle of parking increases.
The minimum curb length is consumed by right angle parking.
Angle Parking
The parking may be by making a angle with curb line like 30°, 45°, 60° etc. The traffic
delay is minimum with angle parking.
Fig: Parallel Parking
Fig: Angle Parking
21

22. 90° Angle Parking
This type of parking can be used where width of road is sufficient. No. of vehicle is
more per running length of road but more width of road is required.
Generally parallel parking is preferred, where width of curb parking space and the
width of street are limited.
Fig: 90° Angle Parking
22

23. 4.1.6 Traffic Control Device
Traffic control device is the medium used for communicating between traffic engineer
and road users. Unlike other modes of transportation, there is no control on the drivers
using the road. Here traffic control devices comes to the help of the traffic engineer.
There are mainly three types of traffic control device as follow:
Traffic Sign
Traffic Signals
Road Markings
4.1.6.1 Traffic Sign
It is a mechanisms which is used by the traffic engineer to communicate with the road
user with the help of some signs.
Types of traffic signs
They can be classified into three main categories.
1. Regulatory signs: These signs require the driver to obey the signs for the safety of
other road users.
2. Warning signs: These sigs are for the safety of on self who is driving and advice the
drivers to obey these signs.
3. Informative signs: These signs provide information to the driver about the facilities
available ahead, and the route and distance to reach the specific destinations.
23

24. a) Regulatory Signs
These signs are also called mandatory signs because it is mandatory that the drivers
must obey these signs. If the driver fails to obey them, the control agency has the right
to take legal action against the driver. These signs have generally black legend on a
white background. They are circular in shape with red borders. The regulatory signs
can be further classified into :
1. Right of Way Series: These include two unique signs that assign the right of way to
the selected approaches of an intersection. They are the STOP sign and GIVE WAY
sign.
2. Speed Series: Number of speed signs may be used to limit the speed of the vehicle
on the road. They include typical speed limit signs, truck speed, minimum speed
signs etc. Speed limit signs are placed to limit the speed of the vehicle to a particular
speed for many reasons. Minimum speed limits are applied on high speed roads like
expressways, freeways etc. where safety is again a predominant reason.
3. Movement Series: These include turn signs, alignment signs, exclusion signs, one
way signs etc. Turn signs include turn prohibitions and lane use control signs. Lane
use signs make use of arrows to specify the movements which all vehicles in the
lane must take. Turn signs are used to safely accommodate turns in un-signalized
intersections. 24

25. Cont…
4. Parking Series: They include parking signs which indicate not only parking
prohibitions or restrictions, but also indicate places where parking is permitted, the
type of vehicle to be parked, duration for parking etc.
5. Pedestrian series: They include both legend and symbol signs. These signs are
meant for the safety of pedestrians and include signs indicating pedestrian only
roads, pedestrian crossing sites etc.
6. Miscellaneous: Wide variety of signs that are included in this category are: a
"KEEP OF MEDIAN” sign, signs indicating road closures, signs restricting vehicles
carrying hazardous cargo or substances, signs indicating vehicle weight limitations
etc.
Fig: Examples of regulatory signs ( stop sign, give way sign, signs for no
entry, sign indicating prohibition for right turn, vehicle width limit sign,
speed limit sign)
25

26. b) Warning signs
Warning signs give information to the driver about the impending road condition. They
advice the driver to obey the rules. These signs are meant for the own safety of drivers.
They call for extra vigilance from the part of drivers. The colour convention used for
his type of signs is that the legend will be black in colour with a white background. The
shape used is upward triangular or diamond shape with red borders.
c) Informative signs
Informative signs also called guide signs, are provided to assist the drivers to reach
their desired destinations. These are predominantly meant for the drivers who are
unfamiliar to the place. The guide signs are redundant for the users who are familiar to
the location.
Fig: Examples of warning signs ( right hand curve sign board,
signs for narrow road, sign indicating railway track ahead)
26

27. Cont…
Some of the examples for these type of signs are route markers, destination signs, mile
posts, service information, recreational and cultural interest area signing etc. Route
markers are used to identify numbered highways. They are written black letters on
yellow background. Destination signs are used to indicate the direction to the critical
destination points, and to mark important intersections. Distance in kilometers are
sometimes marked to the right side of the destination. They are, in general, rectangular
with the long dimension in the horizontal direction. They are colour coded as white
letters with green background.
Fig: Examples of informative signs (route markers, destination
signs, mile posts, service centre information etc)
27

28. 4.1.6.2 Traffic Signal
Traffic signals are automatic traffic control devices which could alternately direct the
traffic to stop and proceed at intersections using red and green traffic light signals as
per the pre-determined time settings.
4.1.6.2.1 Importance of Traffic Signals
 Provide orderly traffic movement of traffic at intersection.
 The quality of traffic flow is improved by forming compact platoons of vehicles,
provided all the vehicle move at approximately the same speed.
 Reduction in accidents due to crossing conflict, notably the right angled collisions.
 Traffic handling capacity is highest among the different types of intersections at
grade.
 Provide a chance to traffic of minor road to cross the continuous traffic flow of the
main road at reasonable intervals of time.
 Pedestrian can cross the roads safely at the signalized intersection.
 When the signal system is properly coordinated, there is a reasonable speed along the
major road traffic.
 Automatic traffic signal may work out to be more economical when compared to
manual control.
28

29. 4.1.6.2.2 Types of Traffic Signal
The signals are classified into the following types:
Traffic control signals
Pedestrian signals
Special traffic signals
Traffic Control Signals
The traffic control signals have three coloured lights which glow facing each direction
of traffic flow namely, red, amber and green. Red light is meant for ‘Stop’, Green light
for ‘Go’ and Amber or yellow light allows the ‘clearance time’ for the vehicle which
enter the intersection area by the end of green time to clear off the intersection, before
the change over to red signal light.
Fig: Traffic Signal Fig: Working of Traffic Signal
29

30. Pedestrian Signals
Pedestrian signals may be installed at the intersections controlled by traffic signals to
enable the pedestrians to safely cross the specified road; in such cases, the pedestrian
signals and their timings are interlinked to operate along with the traffic control signal.
At certain locations of mid block stretches of urban roads with high demand for
pedestrian crossing, separate pedestrian signals may be installed along with appropriate
warring and informatory signs.
Special Traffic Signal
Special traffic signals such as ‘flashing beacons’ me be installed at certain locations in
order to warn the traffic of certain situations. At flashing red signals, the drivers of
vehicle shall stop before entering the nearest cross walk at an intersection or at a stop
line. Flashing yellow signals are cautionary signals meant to signify that drivers may
proceed with caution.
30

31. 4.1.6.3 Road Marking
The road markings are defined as lines, patterns, words or other devices, except signs,
set into applied or attached to the carriageway or kerbs or to objects within or adjacent
to the carriageway, for controlling, warning, guiding and informing the users. The
markings serve as a psychological barrier and signify the delineation of traffic path and
its lateral clearance from traffic hazards for the safe movement of traffic.
4.1.6.3.1 Classification of Road Marking
The road markings are classified as
Longitudinal markings
Transverse markings
a) Longitudinal markings
They are marked along the direction of traffic on the roadway surface, for the purpose
of indicating to the driver, his proper position on the roadway. White is the predominant
colour used in the case of longitudinal markings for separating traffic flow in the same
direction. Yellow colour is used to separate the traffic flow in opposite direction and
also to separate the edges. The lines can be either broken, solid or double solid.
Centre line
Centre line separates the opposing streams of traffic and facilitates their movements.
Usually no centre line is provided for roads having width less than 5 m and for roads
having more than four lanes.
31

32. Cont…
The centre line may be marked with either single solid line, single broken line, double
broken line or double solid line depending upon the road and traffic requirements.
Traffic lane lines
The subdivision of wide carriageways into separate lanes on either side of the carriage
way helps the driver to go straight and also curbs the meandering tendency of the
driver. At intersections etc, these traffic lane lines will eliminate confusion and
facilitates turning movements. Thus they help in increasing the capacity of the road.
Fig: Centre barrier line marking for four lane
road
32

33. No passing zones
No passing zones are established on summit curves, horizontal curves, and on two lane
and three lane highways where overtaking maneuvers are prohibited because of low
sight distance.
Warning lines
They are broken lines with line segments as long as the normal gaps and vice-versa.
They warn the drivers about the obstruction approaches.
Edge lines
These indicate edges of rural roads which have no kerbs to delineate the limits up to
which the driver can safely venture. They should be at least 150 mm from the actual
edge of the pavement. They are painted in yellow or white.
Fig: Warning line marking for
a two lane road
Fig: No passing zone marking at
horizontal curves
33

34. b) Transverse markings
Transverse markings are marked across the direction of traffic. They are marked at
intersections etc.
Stop line
Stop line indicates the position beyond which the vehicles should not proceed when
required to stop by control devices like signals or by traffic police. They should be
placed either parallel to the intersecting roadway or at right angles to the direction of
approaching vehicles.
Pedestrian crossings
Pedestrian crossings are provided at
places where the conflict between
vehicular and pedestrian traffic is
severe.
Fig: Pedestrian marking near an intersection
34

35. Directional arrows
In addition to the warning lines on approaching lanes, directional arrows should be
used to guide the drivers in advance over the correct lane to be taken while approaching
busy intersections. Because of the low angle at which the markings are viewed by the
drivers, the arrows should be very much elongated in the direction of traffic for
adequate visibility.
Fig: Directional arrow marking 35

36. Conclusion
This unit mainly focus on the different types of study to efficient movement of traffic,
improve the facilities, road user safety etc.
There are various type of study like speed, volume, O & D, accidental and parking
Study. These are useful in planning, traffic control and traffic regulations. These studies
are useful in geometric design of road. Accidental study are useful to reduce the
accident rate Spot speed study are used to study the traffic capacity.
This unit also contains importance and types of Traffic Signs, Signals, Road Markings
and Road Intersections etc.
36

37. RTU Questions
1. Write advantage of traffic signal?
2. What is the importance of traffic sign ? What are the different classification of
traffic sign? Explain with example with warning sign.
3. Explain the following:
(i) AADT
(ii) PCU
(iii) 30th highest hourly volume
(iv) Time mean speed and space mean speed
4. Enlist the various traffic studies carried out to analysis the traffic character tics.
5. Explain in detail “3-E’s” with respect to measures for the reduction in accident rate
37

38. 38