01004398

Component

The 2+1 roads have a continuous three-lane cross section with alternating passing lanes. The 2+1 cross section enables passing maneuvers within designated passing lanes without regard to the opposing traffic. In Germany those 2+1 roads have been found out to operate with lower accident rates than conventional two-lane highways. The aim of the last year's research concerning the 2+1 cross section was to analyze the traffic safety and to assess the quality of service. The knowledge about the passing process is still incomplete and is based predominantly on theoretical models. The paper presents selected results of the research project FE 02.223/2002/FRB "Design standard and passing behaviour on 2+1 roads". The research project was sponsored by the Federal Ministry of Transport, Building and Housing. It was concluded in February 2005. The aim of the research project was to enlarge the knowledge about passing processes on 2+1 roads. Above all this knowledge should be used to determine the necessary length of two-lane sections within 2+1 roads. With regard to this aim different methods of determination of the necessary length of two-lane sections were considered. In the end, a single method was developed. The developed method is based on a correlation between traffic volume and the necessary length of two-lane sections depending on traffic safety and different levels of service with regard to the share of incomplete dissolving processes.

01004374

English

20p

2005

3rd International Symposium on Highway Geometric Design

CD-ROM

Figures (6) ; Photos (5) ; References (8) ; Tables (2)

Crash rates; Highway design; Highway safety; Passing lanes; Quality of service; Three lane highways; Traffic volume

Germany

Design; Highways; I20: Design and Planning of Transport Infrastructure

TRIS, TRB, ATRI

Sep 26 2005 3:46PM