The various aids and devices used to
control , regulate and guide traffic may
be called Traffic Control Devices.
The general requirement of Traffic
Control Devices are :
Attention , Time for response and
respect of road users.
TYPES OF TRAFFIC CONTROL
They are of great help in regulating traffic by imparting
message to the drivers about the need to stop , give
way and limit their speeds.
They are of three types-
WARNING OR CAUTIONERY SIGNS
Regulatory signs- They are meant to inform the road
users of certain laws , regulations and prohibitions ;
the violation of these signs is a legal offense.
Warning Signs – They are used to warn the hazardous
conditions that exist or adjacent to the Roadway. The
warning signs in the shape of equilateral triangle with
one point upwards.
Informatory Signs- These signs are used to guide the
road users along routes , inform them of destination
and distance and provide with information to make
travel easier , safe and pleasant.
They are control devices which could alternately direct
the traffic to stop and proceed at intersections using
red and green traffic light signals automatically. The
main requirements of requirements of traffic signal are
to draw attention , provide meaning and time to
respond and to have minimum waste of time.
Types of Traffic Signal-
TRAFFIC CONTROL SIGNALS
1. Traffic control signals- They have three colored
light glows facing each direction of traffic flow.
RED light means to STOP , GREEN means to GO ,
YELLOW or AMBER means allows the
2. Pedestrian Signals- They are meant to give the
right way to pedestrian to cross a road during the
“walk period” when the vehicular traffic shall be
stopped by red or stop signal on the traffic signals
of the road.
Road marking are made of lines , pattern , words ,
symbol or reflection on the pavement , kerb , sides of
islands or on the fixed objects within or near the
The markings are made using paints in contrast with
colour and brightness of the pavements or other back
Types of marking-
REFLECTOR UNIT MARKING
1. Pavement Marking- They may generally be of white
paint. Yellow marking are used to indicate parking
2. Kerb Marking- These may indicate certain regulation
like parking regulations. Also the marking on the kerb
and edges of islands with alternate black and white line
increases the visibility from the a long distance.
3. Object Marking- Physical obstruction on or near the
road hazardous and hence should be properly marked.
4. Reflect Unit Marking- Reflector markers are used as
hazard markers and guide markers for safe driving during
night. Hazards markers reflecting yellow light should be
visible from a long distance of about 150 m.
Traffic islands are raised areas constructed within the
roadway to establish physical channels through which
the vehicular traffic may be guided.
They are mainly four types-
PEDESTRIAN LOADING ISLANDS
1. Divisional islands- They are intended to separate
opposing flow of traffic on a highway with four or
more lanes . By thus dividing the highway into two
one way roadways , the head-on collisions are
2. Channelizing islands- They are used to guide the
traffic into proper channel through the intersection
area. They are very useful as traffic control devices
for intersection at grades , when area is large.
3. Pedestrian Loading Islands- They are provided at
regular bus stop and similar places for the protection
4. Rotary islands- It is the large central island of
rotary intersection ; this island is much larger than
the central island of channelized intersection.