01587123

Component

https://doi.org/10.3141/2588-02

A 2009 crash involving a tanker truck that departed the roadway on a freeway connection ramp led the National Transportation Safety Board to suggest a review of current AASHTO policy for pavement–shoulder cross-slope breaks on horizontal curves to determine whether updates to the design criteria were needed. As part of NCHRP Project 03-105, the research team reviewed and summarized existing policies and conducted a pair of studies focusing on large trucks on horizontal curves. Researchers conducted a vehicle dynamics simulation study and a crash-based study; both were designed to identify patterns and trends in roadway departure crashes involving large trucks and to develop recommendations for corresponding revisions to AASHTO policy for designing cross-slope breaks on horizontal curves. In the vehicle dynamics simulation study, researchers developed and analyzed results from roadway departure models for a tractor single-van trailer truck, a tractor tanker trailer truck, and a tractor double-van trailer truck for various combinations of roadway departure path, approach speed, superelevation, and cross-slope break. This paper summarizes existing policy, describes the study method, and presents findings from the vehicle dynamics simulation study. Results indicate that no changes need to be recommended for AASHTO’s policy on cross-slope break.

01590546

16-2414

English

pp 12–21

2016

Transportation Research Record: Journal of the Transportation Research Board

9780309369794

Print

Figures (7) ; References (13) ; Tables (6)

Geometric design; Highway curves; Highway safety; Ran off road crashes; Slopes; Trucks; Vehicle dynamics

American Association of State Highway and Transportation Officials

Cross slopes (Pavement surfaces); Driving breaks (Countermeasures); Horizontal curvature

Design; Highways; Motor Carriers; Operations and Traffic Management; Safety and Human Factors

TRIS, TRB, ATRI

Jan 12 2016 5:04PM

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