Traffic Operation and Safety of Freeway Weaving Segments in Germany

Abstract

Weaving segments on freeways can be used if the distance between two adjacent interchanges is too small for implementing separate merging and diverging areas. The German Guidelines for the Design of Motorways define different types of weaving segment. In this study, the traffic operation and safety of freeway weaving segments between interchanges in Germany are analyzed. The traffic flow analysis was based on trajectory data obtained from video measurements at weaving segments with different geometric and operating conditions. For the safety analysis, crash data over a period of 5 years were evaluated. Based on the traffic flow measurements, it was found that the majority of the entering and exiting vehicles generally carry out the necessary lane change at the beginning of the weaving segment, so that a minimum segment length of 300 m is sufficient for proper operation. The crash analysis revealed crash rates of freeway weaving segments between interchanges similar to those of basic freeway segments, which contradicts previous concerns against the use of weaving lanes at main carriageways.

Keywords

operations freeway operations freeway analysis

Get full access to this article

View all access options for this article.

References

FGSV. Richtlinien fuer die Anlage von Autobahnen (German Guidelines for the Design of Motorways). German Road and Transportation Research Association (FGSV), Cologne, 2008.

FGSV. Entwurfshinweise für planfreie Knotenpunkte an Straßen der Kategoriengruppe B - Ergänzung zu den RAL-K-2 (RAS-K-2-B). German Road and Transportation Research Association (FGSV), Cologne, 1995.

Pignataro

L. J.

McShane

W. R.

Crowley

K. W.

Lee

Roess

R. P.

Weaving Area Operations Study: Design and Recommendations. Highway Research Record No. 398. Highway Research Board, Washington, D.C., 1972.

Leisch

Completion of Procedures for Analysis of and Design of Traffic Weaving Areas. Final Report, Vol. 1 and 2. U.S. Department of Transportation, Federal Highway Administration, Washington, D.C., 1983.

Reilly

W. R.

Kell

J. H.

Johnson

P. J.

Weaving Analysis Procedures for the New Highway Capacity Manual. Technical Report. Contract No. DOT-FH-61-83-C-0029. FHWA, U.S. Department of Transportation, Washington, D.C., 1984.

Fazio

Development and Testing of a Weaving Operational Design and Analysis Procedures. M.S. thesis. University of Illinois at Chicago Circle, 1985.

Cassidy

M. A.

Proposed Technique for the Design and Analysis of Major Freeway Weaving Sections. Research Report UCB-ITS-RR-90-16. Institute of Transportation Studies, University of California, Berkeley, 1990.

Cassidy

M. J.

May

A. D.

Proposed Analytic Technique for Estimating Capacity and Level of Service of Major Freeway Weaving Sections. Transportation Research Record 1320. Transportation Research Board, Washington, D.C., 1991.

Ostrom

Leiman

May

A. D.

Suggested Procedures for Analyzing Freeway Weaving Sections. Transportation Research Record 1398. TRB, National Research Council, Washington, D.C., 1993, pp. 42–48.

10.

Windover

May

A. D.

Revisions to Level D Methodology of Analyzing Freeway Ramp-Weaving Sections. Transportation Research Record 1457. Transportation Research Board, Washington, D.C., 1995.

11.

Lertworawanich

Elefteriadou

Capacity Estimations for Type B Weaving Areas Based Upon Gap Acceptance. Transportation Research Record 1776. Transportation Research Board, Washington, D.C., 2002.

12.

Lertworawanich

Elefteriadou

A Methodology for Estimating Capacity at Ramp Weaves Based on Gap Acceptance and Linear Optimization. Transportation Research Part B: Methodological, Vol. 37, 2003, pp. 459–483.

13.

Roess

R. P.

Ulerio

Prassa

Schoen

Vandehey

Reilly

Kittelson

Analysis of Freeway Weaving Sections. NCHRP Project 3-75, Final Report. Polytechnic University, Brooklyn, NY, and Kittelson & Associates, Portland, OR, 2008.

14.

Maurmaier

Verkehrstechnische Beurteilung von Verflechtungsspuren und Verteilerfahrbahnen an Kleeblatt-Knotenpunkten. Forschung Straßenbau und Straßenverkehrstechnik, No. 285, Bundesminister für Verkehr, Abteilung Strassenbau, Bonn, 1980.

15.

Schnüll

Maurmaier

Schreyer

Verkehrsablauf in Verflechtungsbereichen mit starken Randströmen zwischen Einfahr- und Ausfahrrampen planfreier Knotenpunkte. Forschung Straßenbau und Straßenverkehrstechnik, No. 383, Bundesminister für Verkehr, Abteilung Strassenbau, Bonn, 1983.

16.

Sueoka

Berechnung und Gestaltung von Verflechtungsbereichen in Autobahnknotenpunkten. Technical University of Darmstadt, Germany, 1987.

17.

Schnüll

Hoffmann

Kölle

Mennicken

Leistungsfähigkeit von Verflech-tungsstrecken an planfreien Knotenpunkten. Forschung Straßenbau und Straßenver-kehrstechnik, No. 796, Bundesminister für Verkehr, Abteilung Strassenbau, Bonn, 2000.

18.

Mann

Whitney

On a Test of Whether One of Two Random Variables is Stochastically Larger Than the Other. Annals of Mathematical Statistics, Vol. 18, 1947, pp. 50–60.