00490643

Component

http://onlinepubs.trb.org...trr/1989/1208/1208-003.pdf

https://scholar.google.co...uman&publication_year=1989

Design for stopping sight distance (SSD) is among the most basic, critical considerations in the total design of a highway. SSD requirements affect all geometric elements--horizontal and vertical alignment and cross section. Despite the importance of SSD, there is continuing, growing dissatisfaction among many design engineers with the current policy and general approach toward SSD. Such dissatisfaction can be attributed to the problems and costs of meeting current design policy, which have changed in recent years, coupled with a lack of evidence of the safety effectiveness of the policy. This paper presents a new approach to SSD design. It involves the abandonment of the concept that a single operational model for SSD is appropriate for all highway types under all conditions. Instead, the approach presented here suggests functional highway classification as the foundation for determining SSD design policy and values. A range of different operational models and driver, vehicle, and roadway parameters would be possible for different classes of highways. This, in turn, allows a range of design values for SSD for a given design speed, rather than just one value for all conditions. The paper presents examples of such models, with assumed values for driver reaction time, pavement friction, and object height. Illustrative calculations of SSD for five different classes of highways are shown. The calculations indicate the potential for SSD design values to vary significantly from those currently shown by the AASHTO policy.

This paper appears in Transportation Research Record No. 1208, Highway Sight Distance Design Issues. Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved

01414043

p. 14-22

1989

Transportation Research Record

0309048079

Figures (4) ; References (7) ; Tables (10)

Classification; Design; Design speed; Drivers; Friction; Height; Highway safety; Highways; Methodology; Obstructions (Navigation); Pavements; Reaction time; Sight distance; Stopping sight distance

Design criteria; Driver reaction; Highway classification

Design; Highways; Pavements; Planning and Forecasting; I21: Planning of Transport Infrastructure

TRIS, TRB, ATRI

Jan 31 1990 12:00AM

• HIGHWAY SIGHT DISTANCE DESIGN ISSUES: AN OVERVIEW
• HORIZONTAL SIGHT DISTANCE CONSIDERATIONS IN FREEWAY AND INTERCHANGE RECONSTRUCTION
• INTERSECTION SIGHT DISTANCE REQUIREMENTS FOR LARGE TRUCKS
• PASSING SIGHT DISTANCE DESIGN FOR PASSENGER CARS AND TRUCKS
• REEVALUATION OF THE USEFULNESS AND APPLICATION OF DECISION SIGHT DISTANCE
• SAFETY EFFECTS OF LIMITED SIGHT DISTANCE ON CREST VERTICAL CURVES
• SIGHT DISTANCE REQUIREMENTS FOR TRUCKS AT RAILROAD-HIGHWAY GRADE CROSSINGS
• STOPPING SIGHT DISTANCE DESIGN FOR LARGE TRUCKS
• STOPPING SIGHT DISTANCE: CAN WE SEE WHERE WE NOW STAND?