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1. Highway Safety
Methods
Adopted By
Civil Engineers

2. Haider Ali Jafferi
Civil Engineer

3.  The main purpose of adopting safety
measures for highways and road sides is:
• To reduce no. of accidents,
• To facilitate safer journey,
• To increase the quality of transit system,
• To maintain the regular traffic flow.
Introduction:

4. Safety Methods
Adopted
By Civil Engineer
• Cross Section
• Rumble Strips
• Design Of Roadside
• Junctions
• Linear villages
• Roundabouts
• Traffic calming road design
• Innovative Interchange and Intersection design
• Traffic signs
• Pedestrian Crossing
• Barriers

5. The main elements of a road cross section are:
 The pavement with the vehicle lanes, edge
strip and markings
 The emergency zone and obstacle free zone
 The embankment and cutting slopes
 The width of the cross section is determined
by the pavement related to the number of
lanes
 The required width of the edge strip
 The shoulders and earthwork slopes and depth
Cross section

6.  To reduce the number and severity of roadway
departure crashes, or run-off-the-road and
cross center line crashes on 2-lane, rural,
undivided roads.
Rumble Strips

7. Rumble Strips (cont)
 Shoulder rumble strips:
Placed on highway shoulders
along the edge of the travel
lane, to prevent single vehicle
run-off-the-road crashes.
 Center line rumble strips:
Placed on or near the center
line, to prevent head-on crashes
and opposite direction
sideswipe crashes.They can also
be helpful to prevent some
crashes when a driver veers
across the center line

8. Rumble Strips (cont)
Advantages:
 Alert drivers upon drifting or deviation.
 The reflective paint helps to increase
visibility.
 Reduce the number of crashes.

9. Design Of Road-Side
 Design of road side must comply the
following essential requirements:
i. The road must be free from ditches and
screeding should be done properly.
ii. Shoulders and edge strips must be
provided.
iii. Super elevations must not be too steep.

10. Design of Road-Side (cont)
iv. Avoid sharper turns.
v. Emergency zones/lanes must be provided.
vi. Wider Obstacle free zones to reduce the risk
in case of road run-off accidents.

12. Junctions
 “A road junction is a
location where
multiple roads
intersect, allowing
vehicular traffic to
change from one
road to another.”

13. Junctions (cont)
 A road junction has to fulfill following
requirements:
i. Visible
ii. Oversee-able
iii. Comprehensible
iv. Completeness

15. LinearVillages
 “A linear village is that part of a (transit) road
which lies within a built-up area.”

16.  Passing a road from public areas must comply
with the special safety needs:
i. Pedestrian Safety
ii. Speed reduction measures
iv. Footpaths, side railings and shoulders
v. Avoid Sharp turns and blind corners

17.  Originated in Europe over 35 years ago.
 Intended to calm (or slow down) traffic.
 Used primarily as a safety measure on low
volume & low speed roadways.
 Traffic calming may involve “physical
changes" to the roadway that slow traffic
down. Some examples:
Traffic Calming Road Design

19.  Using innovative design interchanges &
intersections to help move large volumes of
traffic through limited amounts of space
safely and efficiently.
 Following are the main types:
i. Diverging Diamond Interchange (DDI)
ii. Echelon Interchange
iii. Single Point Interchange (SPI)
Innovative Interchange and Intersection Design

20. InnovativeInterchangeandIntersectionDesign(Cont)
i. Diverging Diamond Interchange (DDI)
This innovative interchange, sometimes called
a “double crossover diamond,” .

21. Innovative Interchange and Intersection Design
(Cont)
Purpose:
 Increase capacity
 Safety
 Decrease congestion
 Minimize the cost of
new infrastructure.
Advantages:
 Safety
 Greater capacity
and efficiency
 Easy navigation
 Suitability

22. Innovative Interchange and Intersection Design
(Cont)
ii. Echelon Interchange
This innovative interchange is designed to accommodate
two high-volume streets. An echelon introduces a bridge,
splitting traffic into two levels, creating two separated
intersections of one-way streets. Because there is no
opposing traffic for left turns there is more green light time
for all movements.
Advantages
 Safety
 Greater capacity
and efficiency

23. Innovative Interchange and Intersection Design
(Cont)
iii. Single Point Interchange
All traffic is controlled by a single set of traffic
signals located in the center of the intersection.

24. Innovative Interchange and Intersection Design
(Cont)
Reasons for considering SPI:
 Better Safety
 Greater capacity and efficiency than conventional
designs
 Also accommodates large trucks.
 Ease of Navigation

25. Traffic Signs
 Traffic signs or road signs are signs erected at
the side of or above roads to give instructions
or provide information to road users.
 Traffic signs generally :
• Control the flow of traffic
• Warns about hazards ahead
• Guide to destination
• Informs roadway services.

26.  Traffic signs are
intentionally color
coded to assist the
operator.
 In traffic signs,
fluorescent material
is used.
 Various sign boards
are used, such as:

27. i. Stop & Yield Sign Boards
 A STOP sign is a
traffic sign to notify
drivers to
completely halt
whileYIELD means
to slow down to at
a point

28. ii. Warning Signs
 Alerts to hazards or
changing in
conditions such as
changes in road
layout, proximity to a
school zone, sharp
turns etc.

29. iii. Guide signs
 Indicates route
markers, distance-
and-destination
signs, and
informational signs.

30. iv. Construction & Maintenance Road
Work Warnings
 The work areas are protected from traffic by
orange (or yellow) warning signs during the
construction or repairing works.
 Help to guide pedestrians and vehicle traffic
safely through a work zone and past any
hazards.

31. Roundabouts
 “A roundabout is a type of circular
intersection or junction in which road traffic
flows almost continuously in one direction
around a central point.”

32. Improved safety Due to Roundabouts