Civil Engineering Reference
In-Depth Information
Table 16.8 Summary of research on the effects of access management techniques
Treatment
Effects
1.
Add continuous TWLTL
35 % reduction in total crashes
30 % decrease in delay
30 % increase in capacity
2.
Add non-traversable median
35 % reduction in total crashes
30 % decrease in delay
30 % increase in capacity
3.
Replace TWLTL with a non-
traversable median
15
57 % reduction in crashes on 4-lane roads
-
25
50 % reduction in crashes on 6-lane roads
-
4.
Add a left-turn bay
25
-
50 % reduction in crashes on 4-lane roads
up to 75 % reduction in total crashes at
unsignalized access
25 % increase in capacity
5.
Type of left-turn improvement
(a) painted
(b) separator or raised divider
32 % reduction in total crashes
67 % reduction in total crashes
6.
Add right-turn bay
20 % reduction in total crashes
Limit right-turn interference with platooned
fl
ow,
increased capacity
7.
Increase driveway speed from
5 to 10 mph
50 % reduction in delay per maneuver; less
exposure time to following vehicles
8.
Visual cue at driveways,
driveway illumination
42 % reduction in crashes
9.
Prohibition of on-street
parking
30 % increase in traf
c flow
20
-
40 % reduction in crashes
10.
Long signal spacing with
limited access
42 % reduction in total vehicle-hours of travel
59 % reduction in delay
57,500 gallons fuel saved per mile per year
Source
Reference [
29
]
16.11 Emerging Congestion Management Strategies
Application of new detection, information, and communications technologies in
transportation increases ef
ciency of the system and provide better levels of service
for travelers in terms of lower traf
c congestion, reduced delays, and safer roads.
The application of these advanced technologies in transportation is popularly
known as
“
Intelligent Transportation Systems,
”
or ITS.
16.11.1 Intelligent Transportation Systems (ITS)
ITS strategies entail use of real-time traf
c
signal controls, better traveler information, roadside electronic screening programs,
integrated corridor management, and vehicle-infrastructure integration (VII).
c information that allows dynamic traf
