Best Practices for Road Weather Management Version 2.0
Title:
Empirical Studies on Traffic Flow in Inclement Weather
Abstract:
The overall goal of the research undertaken in this study was to develop a better understanding of the impacts of weather on traffic flow. The research was intended to study the impact of precipitation on macroscopic traffic flow parameters over a full range of traffic states; the impact of precipitation on macroscopic traffic flow parameters using consistent, continuous weather variables; the impact of precipitation on macroscopic traffic flow parameters on a wide range of facilities; regional differences in reaction to precipitation; and macroscopic impacts of reduced visibility. The work documented in this report was conducted in two parts: literature review and development of a data collection and analysis plan, and analysis and interpretation of the results. The recommended plan combined the use of macroscopic traffic data archives with archived weather data in order to meet the research goals that include achieving better understanding of the impacts of weather on macroscopic traffic flow. The results of the research conducted for this study were helpful in identifying weather impacts of traffic flow in the three cities studied, Minneapolis-St. Paul, Baltimore, and Seattle. No impacts were found on traffic stream jam density, but both rain and snow did impact traffic free-flow speed, speed-at-capacity and capacity and parameters varied with precipitation intensity.
Source(s):
Cambridge Systematics and Virginia Tech Transportation Institute, Prepared for the FHWA Road Weather Management Program
http://www.ops.fhwa.dot.gov/publications/weatherempirical/index.htm
Date: 2006
Author:
Hranac, Sterzin, Krechmer, Rakha, Farzaneh, Arafeh
Keywords:
Speed
Capacity
Driver behavior
Fog
Visibility
Precipitation
Rain
Snow
Mobility
Freeway management
PDF files can be viewed with the Acrobat® Reader®.
