Transportation Research Board releases roundabout, CMV research

By Tyson Fisher, Land Line staff writer | 9/22/2015

Editor's note: This article has been updated to reflect the Transportation Research Board Record is a collection of indepdendent studies.

The Transportation Research Board has recently published a comprehensive collection of studies that look into truck and bus safety on roundabouts and makes recommendations.
Titled “Truck and Bus Safety: Roundabouts 2015,” the Transportation Research Record consists of 10 different studies that address several issues related to roundabouts.

One major point of concern that was addressed in the included research involved traffic congestion and traffic delays at roundabouts as they relate to commercial trucks. More specifically, left-turning trucks posed a greater risk for congestion and delays.

Results in various studies included in the TRB Record found that roundabouts with a free-flow “slip lane” – lanes allowing vehicles to turn at an intersection without entering it – reduced congestion at roundabouts. Slip lanes where vehicles must yield also reduced delays but to a lesser extent.

Locations of roundabouts were also analyzed. Several recommendations were made related to “access features” near roundabouts in commercial areas. More specifically, the recommendations address the following safety issues: driveway corner clearances, median openings, and direct access to activity centers near roundabouts.

The opinions expressed within the studies collected in the Transportation Research Record are not necessarily those of TRB, but rather those of the authors of the various studies.

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