Effect of rainfall on travel time and travel demand

There is an increasing demand from both the transport authorities and road users to have travel time information for 1 to 2 hours ahead allowing users to plan their trip in advance, allowing them to choose the departure time, mode and route. However, accuracy of travel time prediction decreases with the prediction time horizon. Drivers tend to reduce their speed and keeping a longer headway when raining, which affects the lane capacity. Therefore, a more accurate travel time prediction model can be developed if the effect of rain on travel demand and travel time can be established. This paper sets out to determine the impact of rain on daily trips recorded at Tokyo Metropolitan Expressway (MEX) and the effect of rain on travel time. Rainfall data monitored by the Japan Meteorological Agency’s meso-scale network of weather stations are used.