Civil Engineering Reference
In-Depth Information
Fig. 13.3
Relationship of congestion and accident rates on urban highways.
Source
Reference [
2
],
the positive impacts of transportation investment, NCHRP Project 8-36, task 22
compilation of
working papers. Cambridge systematics, transportation research board. February 2002. Page 4
—
6,
-
Fig. 2
Fig. 13.4
Linking traf
c volume, speed, and crashes in urban interstate highways.
Source
Reference [
26
], p 17.
National Academy of Sciences, Washington, DC, Reproduced with
permission of the Transportation Research Board
©
The greatest effect of incidents on congestion occurs during peak hours. One
study [
27
] using data from the 1970s to early 1980s reports that the presence of a
stalled vehicle in a traf
200 vehicle hours to other
motorists; and crashes that involve injuries or spills create larger delays. Each crash
typically lasts 45
c lane can cause a delay of 100
-
90 min, causing 1,200
2,500 vehicle hours of delay [
2
].
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-
