Reliability Benefits of Active Traffic Management A Managed Lanes Case in a French Urban Motorway

摘要

Traffic management aims to ensure a high quality of service for a maximum of users,by decreasing congestion and increasing safety. However, uncertainty regarding travel time(TT) decreases the quality of service and causes users to modify their plans regardless of theaverage TT. Indicators describing TT reliability are being developed and should be used inthe future both for the optimization and for the assessment of active traffic managementoperation. This paper describes a managed lane experiment on a motorway weaving sectionin France - Hard Shoulder Running (HSR) operation- at rush hours. The paper describes thedata measurement and the missing data replacement process. It focuses, however, on TTreliability indicators and on their use for reliability assessment on the basis of anobservational before/after study. It provides some discussion on the advantages anddrawbacks of reliability indicators under different traffic conditions. The before/after studyreports not only the effect of the HSR operation but also of a speed limit campaign whichaffected the free flow travel time. The study particularly shows the difference between usingbuffer times or using buffer indexes. The paper also discusses the difficulty of interpretingthe skew of TT distribution for travel reliability.