Sachpazis Costas: Geotechnical Engineering: A student's Perspective Introduction
1.3_Road Signs & Markings.pdf
1. TRAFFIC CONTROL DEVICES & SAFETY
NEEDS OF DIFFERENT ROAD USERS
Dr. A. Mohan Rao
Principal Scientist, Traffic Engineering and Road Safety
Division
CSIR - Central Road Research Institute, Mathura Road
New Delhi - 110 025
E-mail: amrao.crri@nic.in
2. Integral part of any road design
Often the forgotten part of the road
design
Often there is limited information for
concept design audits
Generally supplied at detailed
design audit stage
3. The standards are broad and allow
for engineering judgment
The designer has not got the right
skills to design the correct signs
and lines
5. Traffic Signs General
Objective of road signs
To notify road users of regulations and provide warning and
guidance needed for safe, uniform and efficient operation.
To promote road safety and efficiency by providing orderly
movement of all road users on all roads
Principles of Road Signs
Road sign should meet five basic requirements
1. Fulfil a need
2. Command attention
3. Convey a clear and simple meaning
4. Command respect from road users; and
5. Give adequate time for response
6. Classification of Road Signs
Mandatory/Regulatory Signs
These signs indicate the prohibition upon certain
kind of vehicle manoeuvre
They are with red circular ring and diagonal bars
with black symbols or arrows or letters on white
background.
Mandatory signs giving positive instructions are
circular with white symbol on a blue background.
They indicate what driver must do compulsorily.
7. The mandatory and warning signs shall be provided with white
background and red border. The legend/symbol for these signs shall be in
black.
8. Power to erect traffic signs
Motor Vehicle act 1988, 2019
Chapter VIII
Sections : 116 (Power to erect traffic signs)
Section 112 (Limits of speed)
Section 115 (Power to restrict the use of vehicles)
Section 119 (Duty to obey traffic signs)
Every driver of a motor vehicle shall drive the vehicle in
conformity with any indication given by mandatory traffic sign
9. Classification of Road Signs contd..
Cautionary/Warning Signs
They are used to caution and alert the road users
to potential danger or existence of certain
hazardous conditions either on or adjacent to the
roadway
They are triangular in shape with red border and
black symbol in white background
Examples of these signs are Hairpin Bend.
Narrow Bridge, Gap in Median, School Ahead etc
10. Informatory /Guide Signs
It indicates location and direction to facilities like "fuel
station" or "eating place" or "parking“
They are rectangular in shape.
16. Size and Siting of Informatory Signs
Advance Direction Signs (ADS) Direction Signs
Reassurance Signs
Place Identification
Signs
1 2 3 4 5 6 7
85th
percentile
“x”
height
(mm)
Minimum
clear
visibility
to the
sign (m)
ONE sign:
distance
from
junction
(m)
TWO signs:
distance
between 1st
and 2nd
sign (m)
“x”
height
(mm)
Minimum
clear visibility
to the sign
(m)
Up to 50
km/h
75
(60)
45 45 -
60
(50)
35
50 - 65
km/h
100
(75)
60 90 50 75
(60)
45
65 - 80
km/h
125
(100)
80 90 - 150 70 100
(75)
60
80 - 90
km/h
150
(125)
90 150 - 225 100 125
(100)
75
Over
90 km/h
200
(150)
115 225 - 300 100 150
(125)
105
17. Colour pattern for direction information signs is given in
Table 8.3. The colours chosen for informatory or guide signs
shall be distinct for different categories of roads.
18. Siting of Signs With Respect to the Carriageway
For two lane roads
• Left side of the carriageway, repeated on the other side of the carriageway
For multilane divided roads
• The signs may be placed on left side of each carriageway
For hill roads
• The signs shall generally be installed on the valley side of the road, unless traffic and road
conditions warrant these to be placed on the hill side
Without kerb and with or without shoulder, the extreme edge of the ground mounted
sign at a distance of 600 mm to 3 m from the carriageway or paved shoulder edge.
For roads with kerbs. it shall not be less than 300 mm away from kerb line
Gantry mounted signs should be mounted on columns preferably 7 m or more
On kerbed roads, the bottom edge of the lowest sign shall not be less than 2.1 m and
not more than 2.5 m
On roads without kerb, the bottom edge of the lowest sign shall not be less than 2 m
and not more than 2.5 m above the crown of the pavement.
19. Provision of overhead signs
The following conditions may be considered while
deciding about the provision of overhead signs:
Traffic volume at or near capacity
Complex interchange design
Three or more lanes in each direction
Restricted visibility
High speed traffic
Insufficient space for ground mounted signs
Large percentage of commercial vehicles
Closely spaced interchanges
20. Orientation of Signs
The signs unless otherwise stated shall normally be
placed at right angles to the line of travel of the
approaching traffic.
Signs relating to parking, however, should be fixed at
an angle (approximately) 15° to the carriageway so as
to give better visibility.
Sign faces are normally vertical, but on gradients it
may be desirable to tilt a sign forward or backward
from the vertical to make it normal to the line of sight
and improve the viewing angle.
Where light reflection from the sign face is
encountered to such an extent as to reduce legibility.
The sign should be turned slightly away from the road
21. STOP Sign
Purpose
• This is for indicating priority for the right of
way. Required to stop before entering a major
road.
22. GIVE WAY Sign
Purpose
• The GIVE WAY sign is used to assign right-of-
way to traffic on certain roadways at
intersections.
23. If desired, distance of places in km may be shown after the
destination names.
If more than one place is to be shown in the same direction,
the names of the places may be grouped and a single arrow
used for direction indication.
Advance Direction Signs
25. Straight Prohibited/No Entry
The signs shall be located at places where the vehicles are not
allowed to enter. It is generally erected at the end of one-way road
to prohibit traffic entering the roadway in the wrong direction and
also at each intersection along the one-way road.
26. Priority to Vehicles from Opposite Direction
• The sign shall be used to indicate that drivers must give priority to vehicles from
opposite direction.
• It should be used only when vehicles at each end of priority sections are clearly visible
to each other.
• The sign must not be displayed to traffic approaching from opposite directions. It must
not be used upside down in an attempt to imply reversed priority.
28. Built Up Area
• The sign shall be used to caution the vehicles
about Built up Area.
•The sign shall be placed at the beginning of
such area
29. MDR-80 Nimapara to Astaranga, Odisha
GOP to Baliga State Highway
GOP to Baliga State Highway
School Sign Board
MDR-80 Nimapara to Astaranga, Odisha
30. GOP to Baliga State Highway
S curve board should be plaaced
Series of Bends
31. Chevron Signs
•At the curved alignment of a roadway, the Chevron signs shall be used to
Inform the drivers about sharpness of curve
• The chevron sign shall be a vertical rectangle and shall be installed always on
the outside of a turn or curve, in line with and at approximately right angle to
approaching traffic.
• Spacing of Chevron signs should be such that the road user always has at least
two signs in view, until the change in alignment eliminates the need for the sign
as given in Table 15.3.
32. • Chevron signs should be visible for a
sufficient distance to provide the road user
with adequate time to react to the change in
alignment
• Depending upon the sharpness of the curve,
Single Chevron (Fig. 15.72), Double Chevron
sign (Fig. 15.74) and Triple Chevron Sign Fig.
15.75) can be installed
• If the Single Chevron signs are to be used for
roads operating at or more than 100kmph,
relatively bigger size single chevron (Fig. 15.73)
shall be used.
36. Route Marker Signs
State Highway Route Marker Sign National Highway Route Marker Sign
Asian Highway Route Marker Sign
Expressway Route Marker Sign
Rectangular plate of
450 mm X 600 mm.
37.
38. Typical Example of Hazardous Reach Treatment with Traffic Calming
using Thermoplastic Bar Markings.
Treatment for Safety of Vulnerable Road Users
39. Rumble Strips
Rumble Strips are provided at places where
speed control is unavoidable in highways and
arterial roads
Rumble strip can be cast in situ with cement
concrete or premix bituminous material
Rumble strips may be provided across the
entire width of carriageway and paved
shoulders
Raised section should be 20 to 30 mm high,
200-300 mm wide and spaced about one meter
centre to centre roughly 6 numbers at one
location
41. Precast ready to install bumps are available and are being
fixed on the road.These bumps can be nailed to the
pavement.
In high speed environment, these bumps prove to be traffic
hazard.
Once the bump get damaged by repeated striking of the
traffic movement, the nail remains on the pavement and
prove to be damaging the tyres of vehicles.
Therefore, its usage is recommended for local and collector
streets
Rumble Strips contd..
45. Introduction
What is Road markings?
Road markings are lines, patterns, words which are
applied or attached to the carriageway
Road markings normally include longitudinal
markings, transverse markings, text and symbols etc.
on the road surfaces.
Why we need Road markings?
For guiding and controlling traffic on a highway and
serve as a psychological barrier
Channelize the pedestrians and cyclists movement
into safe location 45
46. Colour Pattern for Markings
Because of the visibility and good contrast against the road surface, the white
colour should be widely used for road markings.
Longitudinal marking where to convey the message that “it is not permitted to
cross the markings”. It also used to show parking restrictions and to impose
other traffic control.
Indicate new and special markings which are not conventional. Blue is the
colour of public transportation including three wheelers, scooter and
rickshaws.
Distinguish the bicycle and non-motorised transport facilities provided on the
road. Green colour background should be marked at the
intersection to give priority to the cyclists and pedestrians in crossing the
road.
46
White
Yellow
Blue
Green
47. Where multiple road users are sharing the
road space on hazardous locations, the red
colour marking is primarily used to help
people understand the danger.
Red marking is highly recommended on
hazardous intersections and also at places
where pedestrians traffic conflict with the
motorized traffic.
47
Colour Pattern for Markings contd..
Red/Purple
48. Classifications of Road Markings
Pavement Markings are broadly classified into
following seven categories based on the placement of
markings
1. Longitudinal Marking (LM)
2. Transverse Marking (TM)
3. Hazard Marking (HM)
4. Block Marking (BM)
5. Arrow Marking (AM)
6. Directional Marking (OM)
7. Facility Marking (FM) 48
50. • Longitudinal marking at mid-block section of single/
intermediate lane roads, where the carriageway is less than 5.5
m.
• Longitudinal marking at mid-block section for two lane roads,
where the carriageway is 5.5 m to 7 m without any paved
shoulder.
50
Longitudinal Marking for Undivided Roads
51. • For 7.3 m road width the traffic lane line marking is made
continuous where stopping sight distance is not available
at vertical and horizontal curves, but shall be applied for
short sections to avoid provocations by restricting no-
overtaking in a one directional multi-lane carriageway.
51
FourLane Divided Road (One CarriagewayWidth more than 7.3 m)
52. ROAD STUDS
Road studs are used (in series) across the carriageway to serve
as Speed Arrestor coupled with eschewing warning through
the creation of the rumbling sensation to the user.
Colour for Road Studs:
• White - To indicate traffic lane line and centre of
carriageway.
• Red - Mainly to delineate left hand edge of the running
carriageway
• Yellow - Aim to delineate the right hand edge of the
running carriageway (multilane divided carriageways).
• Green - Green road studs are to be employed to indicate
crossable edge line.
