00799058

Component

https://doi.org/10.3141/1701-06

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

The intersection sight distance (ISD) design presented by AASHTO is based on extreme values of the component design variables such as design speed, perception-reaction time (a high percentile), and friction coefficient (a low percentile). A reliability method is presented, based on AASHTO, that does not rely on extreme values but instead considers the moments (mean and variance) of the probability distribution of each random variable. The method also accounts for correlations among the component random variables. In Cases I and II of AASHTO, the variations of the sight distance along both legs of the intersection are considered for both design and evaluation. For evaluation (involving an exiting obstruction), these variations are combined into a single variable that determines whether the corresponding sight line is obstructed. In Case III, only the sight distance leg along the major road has variations. The proposed method is straightforward and involves simple, closed-form mathematics for calculating sight distance and associated reliability. Sensitivity of ISD to various design variables is examined. ISD reliability-based values for various cases are presented from data reported in the literature, and results are compared with current AASHTO design values.

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

English

p. 42-52

2000

Transportation Research Record

0309066808

Figures (5) ; References (27) ; Tables (6)

Design; Intersections; Sight distance

Reliability method

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
• NEW STOPPING SIGHT DISTANCE MODEL FOR USE IN HIGHWAY GEOMETRIC DESIGN
• OPERATING SPEED ON CREST VERTICAL CURVES WITH LIMITED STOPPING SIGHT DISTANCE
• 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