Impedance Effects of Left-Turning Vehicles from the Major Street at a Two-Way Stop-Controlled Intersection

Abstract

At a two-way stop-controlled intersection without a turning lane on the major street, all three movements (right, through, and left) share a lane. To cover the effect of mutual impediments between these movements on the minor street capacity, the major street-shared lane equation, 17-16, is provided by the current Highway Capacity Manual (HCM 2000). This paper shows that this formula should be replaced by an improved equation to get more realistic results. This improved formula is derived. The theoretical concept can also be extended to include the consequences of a short turning lane on the major street. An equation is derived that calculates the effect of the length of the left-turn pocket on the capacity of minor movements.

Get full access to this article

View all access options for this article.

References

Highway Capacity Manual. TRB, National Research Council, Washington, D.C., 2000.

Unsignalized Intersections. Handbuch zur Bemessung von Strassenverkehrsanlagen (German Highway Capacity Manual). Forschungs-gesellschaft fuer Strassen- und Verkehrswesen, Chap. 7. Cologne, Germany, 2001.

Troutbeck

R. J.

, and Brilon

Unsignalized Intersection Theory.

Monograph on Traffic Flow Theory. FHWA, 1999. www.tft.pdx.edu/docs.htm. Accessed Nov. 2008.

Harders

Die Leistungsfaehigkeit nicht signalgeregelter staedtischer Verkehrsknoten (Capacity of Unsignalized Urban Intersections).

Forschung Strassenbau und Strassenverkehrstechnik, No. 76, Bonn, Germany, 1968.

Knote

Die Kapazitaet von Mischstroemen in Nebenstrassenzufahrten von Kreuzungen und Einmuendungen mit Vorfahrtbeschilderung (The capacity of shared lanes at unsignalized crossroads and T-junctions).

Strassenverkehrstechnik, No. 2, S. 75–80, 2006.