SIAS Ltd (SIAS) has been commissioned via the Scottish Road Research Board (SRRB) to investigate the modelling of driver behaviour at road works. The problem, simply stated, is that whilst the layout of many Traffic Management (TM) configurations does not significantly differ from "normal" layouts (for example, a merge from two lanes to one lane), the throughput observed can differ dramatically. The reasons for this appear to lie in driver behaviour. This study is about furthering an understanding of what factors are in play and how they can be better modelled. There has been very little practical information about how driver behaviour, and the resulting impact on traffic conditions, differs with TM in place. The purpose of this research is to try and address this shortfall by providing: an initial examination of the underlying issues involved in modelling driver behaviour at road works some initial ideas about how to positively influence driver behaviour at road works to improve traffic conditions guidance for the modelling of TM at road works, with a view to this guidance being adopted when examining such schemes on behalf of Transport Scotland Traffic modelling is a valuable tool for predicting the impacts of any TM associated with road and structures maintenance and construction. TM is provided at roadworks principally to protect contractors and plant operating on the site. Its secondary function is to control traffic through the road works. Advanced warning signage ahead of the roadworks informs drivers of the works ahead and any action to take. Modelling provides information about potential delays prior to the implementation of TM at roadworks. This information can be relayed to the general public enabling drivers to make informed decisions about re-routeing to avoid the proposed works, changing mode, or not travelling at all. Modelling can also allow the proposed TM layout to be optimised prior to implementation to ensure that delays are minimal. In order to accurately model the impacts of TM at roadworks it is critical to have an understanding of how driver behaviour may differ from "normal" circumstances. The manner in which drivers perceive the TM situation, and the resulting behaviour differs from the behaviour observed in “normal” circumstances such as on approach to merge tapers at the end of D2AP or WS2+1 sections. The reasons for this apparent difference are not well understood despite the very great impact it can have on capacity, delays, safety and emissions. (Author/publisher)
Abstract