Valuation of travel time savings in the presence of simultaneous activities

Time sharing between activities remains an indispensable part of everyday activity pattern. However, the issue has not yet been fully acknowledged within the existing time allocation models, potentially resulting in inaccuracies in valuing travel time savings. Therefore this study is aimed at addressing this gap by investigating the potential impact of introducing time sharing within such a framework, as well as factors determining it as represented by travel activities. In doing so, time constraint in the time allocation model of Small was modified to enable sharing the same time interval between different activities. The resulting expression indicated that such an augmentation could lead to lower estimates of value of time as a resource. On the other hand, empirical research based on the data from the National Passenger Survey 2004 used for calibrating cross-nested logit model indicated a number of factors affecting the choice of travel activities. It was discovered that significant include possession of equipment allowing particular activities, e.g. newspaper, paperwork or ICT devices, companionship, gender, length of the journey, frequency of using the service, possibility of working on the train, journey planning in advance, first class travel, termination of the trip in central London, peak-time travel and availability of seating.