01537320

Monograph

http://www.trb.org/Main/Blurbs/171270.aspx

http://www.trb.org/Publications/Blurbs/171270.aspx

Sharp, horizontal curves on steep downgrades represent a potential safety concern for vehicles, especially heavy vehicles. Examples where this combination may occur are interchange ramp movements, curves on mountainous roads, or high-speed downgrade curves on controlled-access roadways. At these locations, the complicating factors of grade, pavement cross slope, and pavement friction fully tax the driver’s ability to provide correct vehicle positioning without compromising control of the vehicle. Superelevation criteria, horizontal curvature, and other associated geometric criteria needed to be developed for situations where steep grades are located on sharp horizontal curves. This report provides superelevation criteria for horizontal curves on steep grades. A series of field studies and vehicle dynamics simulations were undertaken to investigate combinations of horizontal curve and vertical grade design. Three classes of passenger vehicles and three classes of trucks were considered for safety analysis. The report provides design guidance based on the analyses for sharp horizontal curves on steep grades.

Project 15-39

English

190p

2014

NCHRP Report

9780309307901

Print

Appendices; Figures; References; Tables

Design practices; Highway curves; Highway design; Highway grades; Highway safety; Superelevation

Design; Highways; Operations and Traffic Management; Safety and Human Factors; I20: Design and Planning of Transport Infrastructure; I82: Accidents and Transport Infrastructure

TRIS, TRB, ATRI

Sep 11 2014 11:57AM