Best Practices for Road Weather Management Version 2.0

Title:

Temporary Losses of Highway Capacity and Impacts on Performance: Phase 2

Abstract:

The Oak Ridge National Laboratory, sponsored by the Federal Highway Administration (FHWA), made an initial attempt to provide nationwide estimates of the capacity losses and delay caused by temporary capacity-reducing events (Chin et al. 2002). This study, called the Temporary Loss of Capacity (TLC) study, estimated capacity loss and delay on freeways and principal arterials resulting from fatal and non-fatal crashes, vehicle breakdowns, and adverse weather, including snow, ice, and fog. Prior to the first phase of this study, which was completed in May of 2002, no nationwide estimates of temporary losses of highway capacity by type of capacity-reducing event had been made. This report describes the second phase of the TLC study (TLC2). TLC2 improves upon the first study by expanding the scope to include delays from rain, toll collection facilities, railroad crossings, and commercial truck pickup and delivery (PUD) activities in urban areas. It includes estimates of work zone capacity loss and delay for all freeways and principal arterials, rather than for Interstates only. It also includes improved estimates of delays caused by fog, snow, and ice, which are based on data not available during the initial phase of the study. Finally, computational errors involving crash and breakdown delay in the original TLC report are corrected.

Source(s):

Oak Ridge National Laboratory and University of Tennessee

http://www-cta.ornl.gov/cta/Publications/Reports/ORNL_TM_2004_209.pdf

Date: 2004

Author:

Chin, et al

Keywords:

Fog
Snow
Ice/Frost
Mobility
Rain
Precipitation
Visibility

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