Traffic Control Devices for engineering studies.

1. Traffic Control Devices

2.  The various aids and devices used to
control, regulate and guide traffic are:
• Signs
• Signals
• Markings
• Islands

3. Requirements of a
Traffic Control Device
 Fulfill a need
 Command attention
 Convey a clear, simple meaning
 Command respect of road users
 Give adequate time for proper
response

4. General Color Coding
 Yellow – general warning
 Red – stop or prohibition
 Green – Direction guidance
 Orange – construction and maintenance warning

5.  Traffic Signs are devices mounted on a fixed
support (permanent signs) or portable
support (temporary signs) whereby a specific
message is conveyed by means of words or
symbols.
 As per IRC, there are three types of traffic
signs :-
1)Regulatory or Mandatory signs
2)Warning signs
3)Informatory signs

6.  These are meant to inform the road users of certain laws,
regulations and prohibitions, the violation of the signs is a
legal offence
 They are classified as:-
1. Stop and give way signs
2. Prohibitory signs
3. No parking or No stopping vehicles
4. Speed limit and vehicle control signs
5. Restriction end signs
6. Compulsory direction control signs

8.  Warning signs are used to warn the road
users of certain hazardous conditions that
exists on the roadway.
 These signs are in the shape of equilateral
triangle.
 They are having white background, red
border and black symbols.
 The side of triangle is 45cm.

11.  These signs are used to guide the road users along
routes, inform them about destinations and distances
and provide information to make travel easier, safe and
pleasant.
Various Informatory signs are:
i. Direction and place identification signs
ii. Facility information signs
iii. Parking signs
iv. Flood gauge

13.  These are provided at road intersections.
 These are control devices which could alternatively
direct the traffic to stop proceed at intersections using
red and green light signals automatically.
 The main requirement of traffic signals are to draw
attention.

14. 1. Maintain orderly flow of traffic.
2. Reduce certain types of accidents.
3. Improves safety and efficiency of movement
of vehicles.
4. Pedestrians can cross the roads safety.
5. More economical than manual control.
6. Increase in speed along the major road
traffic.

15.  The rear and end collision may increase.
 Improper design and location of signals may
lead to violations the control systems.
 Failure of the signal due to electrical power
failure or any other defects may cause
confusion to the road users.

16.  Fixed time signals
 Manually operated signals

18.  These are the lines, patterns, words of other devices for
control, warning and guidance or information of road
users.
Various types of markings are:-
1. Pavement markings
2. Kerb markings
3. Object markings
4. Reflector markings

19.  These are generally be of white paint.
 Yellow colour marking are used to indicate parking
restrictions.

20.  Marking on the kerb indicate certain regulations like
parking regulations.
 Marking on the kerb and edges of islands with
alternative black and white line increase the visibility
from a long distance.

21.  Physical obstruction on or near the roadway are
hazardous and hence should be properly marked.
 Typical obstructions are signs and signals, traffic
islands, narrow bridges, culvert.

22.  These are used as hazard markers and guide
markers for safe driving during night.
 These markers should be visible from a long
distance of about 150 m.

23.  Highway Engineering By Dr. R. P. Rethaliya.
 Google Images