this is a brief introduction to various traffic engineering basic characteristics which are useful in designing any corridor or passage with safety & reliability.

2. Semester : BE - 5th Civil-A
Subject : Highway Engineering
Code : 2150601
Presentation On : Traffic Engineering
Prepared by : Eddy Ankit Gangani
eddygangani@gmail.com

3.  What isTraffic Engineering ?
 Scope of traffic Engineering
 Traffic System Components
 Traffic Characteristics – Road User Characteristics
Vehicular Characteristics
Road Characteristics

4.  Traffic Engineering : It is
very important that traffic
flow on roads should be
efficient-safe-rapid.
 Traffic Engineering is the
branch which deals with
science of measuring
traffic ,Designing &
Operating system to
achieve Safe& efficient
movement of persons as
well as goods.

5.  TrafficCharacteristics
 Traffic studies & analysis
 Traffic operation – control
 Planning & Analysis
 Geometric Design
 Administration & Management

6.  Road users-drivers, pedestrians, bicyclists, and
passengers
 Vehicles
 Streets and highways
 Traffic control devices
 The general environment

7. Traffic Characteristics
Road User
Characteristics
Vehicular
Characteristics
Permanent-
Vision,Hearing,Re
action time
Temporary-
Fatigue,Alchohol,Illn
ess,Drugs
Traffic Stream
Facilities
Atmosphere
Locality
Physical Mental Psychological Environmental
Attentiveness
Fear
Anger
Superposition
Knowledge
Skill
Experience
Intelligence
Literacy

8.  Physiological–Measurable and UsuallyQuantifiable
 Psychological–Much more difficult to measure and quantify
 • Psychological : Desired speeds
Desired safety distances
 • Physiological : Perception-Reaction time
Visual factors
Hearing
 The traffic engineer must deal with elderly drivers as well as 18-year-olds, aggressive drivers
and timid drivers, and drivers subject to myriad distractions both inside and outside their
vehicles.

9.  Field ofVision :The most
important characteristic of
drivers is their ability to see!
 Traffic Signs: Location,
Height, Shapes, Colors
 The peripheral vision field
narrows, as speed increases,
to as little as 100° at 20 mi/h
and to 40° at 60 mi/h.

10.  Perception-ReactionTime : The second critical driver characteristic is
perception-reaction time (PRT).
 Detection. In this phase, an object or condition of concern enters the
driver’s field of vision, and the driver becomes consciously aware that
something requiring a response is present.(Perception=VisionAwareness)
 Identification. In this phase, the driver acquires sufficient information
concerning the object or condition to allow the consideration of an
appropriate response.(Intellection- Interpretation)
 Decision.Once identification of the object or condition is sufficiently
completed, the driver must analyze the information and make a decision
about how to respond.
 Response. After a decision has been reached, the response is now
physically implemented by the driver.(Volition= physical response)
 d = 0.278 S.t

11. Traffic Characteristics
Road User
Characteristics
Vehicular
Characteristics
Dimensions
Weight
Maximum
Turning
Radius
Speed
Acceleration
Braking System
Lighting System
Vehicle Design
Tyre
Static Dynamic

12.  VehicleCategories : AASHTO - Four main
categories
 Passenger type-all passenger cars, SUVs, minivans,
vans, and pickup trucks.
 Buses-intercity motor coaches, transit buses, school
buses, and articulated buses
 Trucks-single-unit trucks, tractor-trailer, and
tractorsemi-trailer combination vehicles
 ▫ Recreational vehicles-motor homes, cars with various
types of trailers (boat, campers, motorcycles, etc.)

13.  Braking and deceleration
 Acceleration
 Low-speed turning characteristics
 High-speed turning characteristics
 Size = Height*Width*Length
 Weight
 Sight Distance
 Super Elevation
 Curves
 Capacity

14.  • High-speed turning characteristics
 S : Speed km/h
 R : Curve Radius m
 e : Super elevation rate %
 f : Coefficient of side friction

15.  Braking and deceleration
 Acceleration
 Low-speed turning characteristics
 High-speed turning characteristics
 Size = Height*Width*Length
 Weight
 Sight Distance
 Super Elevation
 Curves
 Capacity

16.  Friction – Skid + Slip
 Unevenness
 Light Reflecting Characteristics

17.  Skid : vehicle slide without revolving
 Slip : wheel revolves more than longitudinal
distance along the road.(acceleration)
 Factors affecting :
Type of Pavement
Roughness of surface
Dry-wet-smooth pavement conditions
Conditions of tyres
Speed of vehicles
Brake efficiency