Road Weather Management Program
photos of lightning, trucks plowing snow, an empty road before a storm, and an evacuation
Office of Operations 21st century operations using 21st century technologies

Best Practices for Road Weather Management Version 2.0

Best Practices > Publications > Publication Titles

Title:

Relationships Among Urban Freeway Accidents, Traffic Flow, Weather and Lighting Conditions

Abstract:

Linear and nonlinear multivariate statistical analyses are applied to determine how the types of accidents that occur on heavily used freeways in Southern California are related to both the flow of traffic and weather and ambient lighting conditions. Traffic flow is measured in terms of time series of 30-second observations from inductive loop detectors in the vicinity of the crash prior to the time of its occurrence. Results indicate that the type of crash is strongly related to median traffic speed and to temporal variations in speed in the left and interior lanes. Hit-object crashes and crashes involving multiple vehicles that are associated with lane-change maneuvers are more likely to occur on wet roads, while rear-end collisions are more likely to occur on dry roads during daylight. Controlling for weather and lighting conditions, there is evidence that crash severity is influenced more by volume than by speed.

Source(s):

California Partners for Advanced Transit and Highways (PATH), University of California-Berkeley

http://repositories.cdlib.org/cgi/viewcontent.cgi?article=1147[amp]context=its/path

Date: 2001

Author:

Golob, Recker

Keywords:


Crashes
Safety
Speed
Volume
Mobility
Adverse weather
Freeway management
Pavement condition

PDF files can be viewed with the Acrobat® Reader®.
Office of Operations