00799053

Component

https://doi.org/10.3141/1701-01

http://scholar.google.com...oppa&publication_year=2000

Stopping sight distance is an important design parameter in that it defines the minimum sight distance that must be provided at all points along the highway. Thus, it influences geometric design values, construction costs, and highway safety. Stopping sight distance is defined as the sum of two components--brake reaction distance and braking distance. The basic model for calculating stopping sight distances was formalized in 1940, and the model's parameters have been altered to compensate for changes in eye height, object height, and driver behavior over the past 50 years. Recent studies, however, question whether the model's parameters and assumptions represent real-world conditions. A new model for determining stopping sight distance requirements for geometric design of highways is presented. This model is based on parameters describing driver and vehicle capabilities that can be validated with field data and defended as safe driving behavior. More than 50 drivers, 3,000 braking maneuvers, 1,000 driver eye heights, and 1,000 accident narratives were used to develop the recommended parameter values for the new model. The recommended values are attainable by most drivers, vehicles, and roadways. This model results in stopping sight distances, sag vertical curve lengths, and lateral clearances that are between the current minimum and desirable requirements and crest vertical curve lengths that are shorter than current minimum requirements.

This paper appears in Transportation Research Record No. 1701, Design Speed, Operating Speed, and Sight Distance Issues.

English

p. 1-8

2000

Transportation Research Record

0309066808

Figures (4) ; References (8) ; Tables (2)

Behavior; Braking; Drivers; Eye location; Geometric design; Highway design; Mathematical models; Stopping sight distance

Lateral clearances; Vertical curvature

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

TRIS, TRB, ATRI

Sep 29 2000 12:00AM

• DESIGN SPEED AND OPERATING SPEED IN RURAL HIGHWAY ALIGNMENT DESIGN
• DETERMINING THE BEST METHOD FOR MEASURING NO-PASSING ZONES
• DRIVER BRAKING PERFORMANCE IN STOPPING SIGHT DISTANCE SITUATIONS
• EVALUATION OF THE PASSING PROCESS ON TWO-LANE RURAL HIGHWAYS
• GEOMETRIC DESIGN OF LOW-SPEED URBAN STREETS
• MATHEMATICAL MODELS OF VEHICULAR SPEED ON MOUNTAIN ROADS
• OPERATING SPEED ON CREST VERTICAL CURVES WITH LIMITED STOPPING SIGHT DISTANCE
• RELIABILITY APPROACH TO INTERSECTION SIGHT DISTANCE DESIGN
• SAFETY EFFECTS OF LIMITED STOPPING SIGHT DISTANCE ON CREST VERTICAL CURVES
• SIGHT DISTANCE FOR STOP-CONTROLLED INTERSECTIONS BASED ON GAP ACCEPTANCE
• SPEED REDUCTION AS A SURROGATE FOR ACCIDENT EXPERIENCE AT HORIZONTAL CURVES ON RURAL TWO-LANE HIGHWAYS
• SPEED-PROFILE MODEL FOR A DESIGN-CONSISTENCY EVALUATION PROCEDURE IN THE UNITED STATES
• SUMMARY OF DESIGN SPEED, OPERATING SPEED, AND DESIGN CONSISTENCY ISSUES
• TRUCK SPEED PROFILES