00221079

Component

http://onlinepubs.trb.org...s/hrr/1970/312/312-002.pdf

THIS ANALYSIS WAS CONDUCTED ON DATA COLLECTED FOR THE INTERSTATE SYSTEM ACCIDENT RESEARCH, STUDY II. THIS STUDY, WHICH WAS INITIATED IN 1961, HAS AS ITS OBJECTIVE THE DETERMINATION OF THE RELATIONSHIP BETWEEN THE GEOMETRICS OF THE INTERSTATE HIGHWAY SYSTEM AND ITS ACCIDENT EXPERIENCE. THE ANALYSIS REPORTED HERE IS CONCERNED WITH THE RELATIONSHIP BETWEEN LENGTH OF WEAVING AREAS, ACCELERATION LANES, AND DECELERATION LANES AND THE ACCIDENT EXPERIENCE OF THESE TYPES OF UNITS. ALSO CONSIDERED IN THE ANALYSIS WAS THE NUMBER OF VEHICLES UTILIZING THESE UNITS AND THEIR RELATIONSHIP TO THE TOTAL NUMBER OF VEHICLES USING THE INTERSTATE. RESULTS OF THIS ANALYSIS INDICATE THAT INCREASING THE LENGTH OF WEAVING AREAS WILL REDUCE THE ACCIDENT RATE AND THAT INCREASING THE LENGTH OF ACCELERATION LANES WILL REDUCE ACCIDENT RATES IF THE PERCENTAGE OF MERGING VEHICLES IS GREATER THAN 6 PERCENT OF THE MAINLINE VOLUME. INCREASED LENGTH OF DECELERATION LANES WILL ALSO REDUCE ACCIDENT RATES BUT TO A LESSER DEGREE THAN THE COMPARABLE INCREASE OF LENGTH OF ACCELERATION LANES. A SMALLER DECREASE IN ACCIDENT RATE BECOMES APPARENT AFTER THE DIVERGING TRAFFIC EXCEEDS 6 PERCENT OF THE MAINLINE TRAFFIC. ONLY THOSE VARIABLES SPECIFIED IN THE REPORT WERE CONSIDERED, AND THEREFORE APPLICATION OF THE RESULTS MUST BE LIMITED ONLY TO THOSE VARIABLES. /AUTHOR/

Paper sponsored by Committee on Operational Effects of Geometrics and presented at the 49th Annual Meeting. 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

01410251

Bellis, W R; Byington, S R; Deacon, John A

pp 17-32

1970

Highway Research Record

Print

Figures (8) ; References (4) ; Tables (5)

Acceleration lanes; Crash rates; Data collection; Deceleration lanes; Geometric design; Length; Speed change lanes; Traffic volume; Weaving sections

Interstate Highway System

Highways; Safety and Human Factors

TRIS, TRB

Oct 26 1970 12:00AM

• A SAFETY EVALUATION OF CURRENT DESIGN CRITERIA FOR STOPPING SIGHT DISTANCE
• ACCIDENTS AT MEDIAN CROSSOVERS
• AN EVALUATION OF DESIGN CRITERIA FOR OPERATING TRUCKS SAFELY ON GRADES
• PASSING PERFORMANCE WITH IN-CAR DISPLAYS
• RELATIONSHIP BETWEEN CURVATURE AND ACCIDENT EXPERIENCE ON LOOP AND OUTER CONNECTION RAMPS
• RELATIONSHIP BETWEEN LIGHTING AND ACCIDENT EXPERIENCE BETWEEN INTERCHANGES
• RELATIONSHIP OF RURAL HIGHWAY GEOMETRY TO ACCIDENT RATES IN LOUISIANA
• VISIBILITY PROBLEMS IN CREST VERTICAL CURVES