Best Practices for Road Weather Management Version 2.0

Title:

The Components of Congestion: Delay from Incidents, Special Events, Lane Closures, Weather, Potential Ramp Metering Gain, and Excess Demand

Abstract:

A method is presented to divide the total congestion delay in a freeway section into six components: the delay caused by incidents, special events, lane closures, and adverse weather; the potential reduction in delay at bottlenecks that ideal ramp metering can achieve; and the remaining delay, due mainly to excess demand. The method can be applied to any site with minimum calibration. It requires data about traffic volume and speed; the time and location of incidents, special events and lane closures; and adverse weather. Applied to a 45-mile section of I-880 in the San Francisco Bay Area, the method reveals that incidents, special events, rain, potential reduction by ideal ramp metering, and excess demand respectively account for 13.3 percent, 4.5 percent, 1.6 percent, 33.2 percent and 47.4 percent of the total daily delay.

Source(s):

85th Transportation Research Board (TRB) Annual Meeting; California State University-East Bay, DKS Associates and University of California-Berkeley

http://www.sci.csueastbay.edu/~jkwon/papers/2006_pie.pdf

Date: 2006

Author:

Kwon, Mauch, Varaiya

Keywords:

Adverse weather
Incidents
Volume
Speed
Access control
Capacity
Traffic control

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