Evaluating Networkwide Effects of Variable Message Signs in the Netherlands

Abstract

The use of variable message signs (VMSs) is generally considered to be a powerful tool to influence route choice so as to increase safety and comfort during driving and improve network performance and to make optimum use of available capacity. Assessing whether such effects actually occur when VMSs are installed is a difficult task. This paper summarizes an extensive evaluation study carried out on the installation of 14 new VMSs on the Amsterdam orbital motorway. The study involves a number of issues. First, a networkwide analysis of aggregate performance indicators, such as traffic performance, severity of congestion, and travel time delay, is included. Second, the relation between the messages displayed on the VMS and the travel times experienced by drivers is analyzed. Finally, a stimulus-response analysis to find out how drivers actually respond to the messages is described. The study showed that the use of VMSs has a positive impact on network performance in the Amsterdam freeway system. Total congestion has decreased, and traffic performance has increased. Variation in congestion has decreased as well as variation in average travel speed. This finding implies that travel time has become more reliable and that the traffic flow is more homogeneous. The technical assessment showed that the displayed queue lengths, if interpreted correctly by drivers, are a good measure for expected delay. User response analysis showed that information has a significant effect on route choice. In general, the VMSs were found to improve the efficiency and reliability of the freeway system.

The combined effect of information and experience on drivers’ route-choice behavior

“…In addition, other studies applied fuzzy logic principles like ''if-then'' rules (Peeta and Yu 2005;Lotan 1993) or dynamic assignment and micro simulation using artificial agents (Nakayama et al 2001;Nakayama and Kitamura 2000;Nakayama et al 1999;Bonsall et al 1997). A few studies attempted to investigate information impacts using revealed preference field studies of real locations or ATIS systems (Fujii and Kitamura 2000;Kraan et al 1999;Deakin 1997;Wardman et al 1997;Khattak and Khattak 1996). The current study is designed to contribute to this line of empirical research by building on recent basic behavioral research.…”

A Parsimonious Method for Offline Freeway Travel Time Estimation From Sectional Speed Detectors

“…For example, the Flemish authorities are currently reconstructing and storing the daily travel times on their entire highway network. Initiatives like this are necessary to monitor the performance year after year and to evaluate traffic managing implementations that influence accessibility and travel time reliability (Chen, Yang, Lo, & Tang, 2002;Chen, Skabardonis, & Varaiya, 2003;Kraan, van der Zijpp, Tutert, Vonk, & van Megen, 1999). A second use of offline travel times is for calibrating travel and traffic models (Ashok, 1996;Cipriani, Florian, Mahut, & NIgro, 2010).…”

The effect of variable message and speed limit signs on mean speeds and speed deviations

“…Emmerink et al (1996) and Bonsall and Palmer (1999) conclude that good driver compliance cannot necessarily be assumed. Kraan et al (1999) conclude that VMSs significantly influence route choice, thereby decreasing total congestion and increasing travel time reliability by reducing the variance of travel times and congestion.…”