In the pursuit of sustainable mobility policy makers are giving more attention to cycling. The potential of cycling is shown in countries like the Netherlands, where cycling covers 25 % of all person trips. However, the effect of policy interventions on cycling demand is difficult to measure, not least caused by difficulties to control for changing context variables like weather conditions. According to several authors weather has a strong influence on cycling demand, but quantitative studies about the relationship are scarce. We therefore further explored this relationship, with the aim of contributing to the development of a generic demand model with which trend and coincidence in bicycle flows might be unraveled. The study is based on time-series between 1987 and 2003 of daily bicycle flows, collected on 16 cycle paths near two cities in the Netherlands. The regression analyses show that, not surprisingly, recreational demand is much more sensitive to weather than utilitarian demand. Most daily fluctuations (80 %) are described by weather conditions, and no less than 70 % of the remaining variation is locally constrained. The regression can therefore mainly be improved by incorporating path specific, as yet unknown, variables. We used the regression results to calculate weather-inclusive bicycle flow predictions and found indications of a downward trend in recreational demand. This trend has been off-set in the observed flows by more favorable weather conditions over the years considered.
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.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.