Citation

McCoy PT, Hoppe WJ. Transp. Res. Rec. 1986; 1100: l-9.

Copyright

(Copyright © 1986, Transportation Research Board, National Research Council, National Academy of Sciences USA, Publisher SAGE Publishing)

DOI

unavailable

PMID

unavailable

Abstract

A time-lapse film study of the traffic operations on 14 intersection approaches on rural two-lane highways in Nebraska was conducted. The purpose of the study was to evaluate the safety effects of turning lanes on the uncontrolled approaches of intersections on rural two-lane highways. The turning lanes evaluated were left-turn, right-turn, and fly-by lanes. Traffic operations on the approaches with turning lanes were compared with those on similar approaches without turning lanes to determine the safety effects of the turning lanes. The measures of safety effectiveness used in the study were (a) standard deviation of mean approach speed, (b) traffic conflict rate, (c) frequency of abnormal turning maneuvers, and (d) improper lane utilization. Lower values of these measures were assumed to be indicative of safer traffic operations. The results of the study indicated that the provision of turning lanes on uncontrolled approaches of intersections on rural two-lane highways improved the safety of traffic operations on these approaches, especially those without paved shoulders. It was also apparent from the results of the study that consideration must be given to the adequate design of these lanes, particularly left-turn and fly-by lanes, in order to eliminate their improper use and encroachments by turning vehicles on adjacent through lanes, which negate the safety benefits provided by such lanes.

Record URL:
http://onlinepubs.trb.org/Onlinepubs/trr/1986/1100/1100-001.pdf

Language: en

Keywords

ROADS AND STREETS - Intersections; HIGHWAY TRAFFIC CONTROL; HIGHWAY ENGINEERING; TRANSPORTATION - Accident Prevention