Questionnaire surveys to evaluate user response to variable message signs in an urban network

The use of variable message signs (VMS) to provide traffic information is widespread, but success depends upon behavioural response to the sign messages. The research described here focuses on user acceptance of VMS located in an urban road network (Southampton, UK), and investigates the public's perceived effectiveness and usefulness of these signs through the use of revealed preference questionnaire surveys and travel diaries. Three hundred and sixty-five commuters regularly driving into Southampton from the outskirts of the city completed a travel diary for a 5-day period as well as a general questionnaire, and 660 infrequent travellers to Southampton completed the general questionnaire. The study showed that it is difficult to capture a meaningful sample size of respondents passing an 'active' VMS in a real-life incident scenario. Less than 1% of the commuter sample stated that they had diverted to an alternative route during the travel diary week as a result of VMS information, although this did correspond to 53% of those 45 drivers originally intending to travel past the incident location. The results showed that the VMS messages were well-understood and legible, and also indicated that a default VMS message reporting no problems in the network can indirectly affect a driver's route choice.