00966547

Component

https://doi.org/10.3141/1847-08

http://scholar.google.com...kkar&publication_year=2003

Limited research is available to help transportation agencies make decisions about installing right-turn deceleration lanes at uncontrolled approaches of unsignalized intersections and driveways. Criteria for right-turn lanes developed by some agencies do not adequately consider the effects of through and right-turn movement volumes and speeds. To evaluate the need for right-turn lanes, the percentage of through vehicles behind right-turning vehicles in the outside (right) lane that perform evasive maneuvers because of the presence of right-turning vehicles has been used as a surrogate. This measure is difficult to use under different combinations of volumes, speeds, and other operating conditions; it also cannot be estimated from traffic simulation models if these models are used to evaluate the need for right-turn deceleration lanes. Safety is the most important factor when deciding to provide a deceleration right lane. The speed differential between through vehicles affected by right-turning vehicles and those not affected by these turns is used to determine the need for right-turn deceleration lanes at unsignalized intersections. The speed differential measure has been shown to be a surrogate to safety and to be related to crash involvement. To determine the total speed differential caused by right-turning vehicles in the outside lane, two variables are needed: the number of through vehicles in the outside lane affected by right-turning vehicles and the average drop in speed of affected vehicles. Total speed differential can be used to evaluate the need for a right-turn deceleration lane.

This paper appears in Transportation Research Record No. 1847, Operational Effects of Geometrics 2003.

English

p. 58-65

2003

Transportation Research Record

0309085837

Figures (4) ; References (7) ; Tables (5)

Deceleration lanes; Driveways; Right turn lanes; Right turns; Through traffic; Traffic safety; Traffic speed; Traffic volume; Unsignalized intersections

Speed differential

Highways; Operations and Traffic Management; I73: Traffic Control

TRIS, TRB, ATRI

Dec 8 2003 12:00AM

• COMPARISON OF OPERATIONS OF SINGLE-POINT AND TIGHT URBAN DIAMOND INTERCHANGES
• COMPARISON OF THE NEW W-INTERCHANGE WITH CONVENTIONAL INTERCHANGES
• DETERMINATION OF STORAGE LENGTHS OF LEFT-TURN LANES AT UNSIGNALIZED INTERSECTIONS USING M/G2/1 QUEUING
• DEVELOPMENT OF DESIGN VEHICLES FOR HANG-UP PROBLEM
• EFFECTS ON ROAD SAFETY OF CONVERTING INTERSECTIONS TO ROUNDABOUTS: REVIEW OF EVIDENCE FROM NON-U.S. STUDIES
• OPTIMAL LOCATION OF U-TURN MEDIAN OPENINGS ON ROADWAYS
• TRAFFIC PLANNING MODELS FOR SINGLE-POINT AND TIGHT DIAMOND INTERCHANGES