Modelling joint travel in London from the 2001 London area travel study data.

One of the key advances in activity-based models is the ability to capture intra-household interactions, both how individual travel by one household member impacts other members and how individuals choose to travel together. While many studies in the past have dealt with joint travel as a means of pick-up/drop-off activities, there is not a clear understanding yet of joint travel as a means of joint activity participation. This paper will present a model of joint travel for participation in non-mandatory activities (encompassing household maintenance and recreational activities) between household members, including all adults and children in the household. The data used will be from the 2001 London Area Travel Study (LATS), a rich dataset of nearly 30,000 households in Greater London. While major research questions such as where individual or joint travel should be placed in the modelling hierarchy cannot be fully determined using cross-sectional data such as the 2001 LATS, the data does serve to better understand the factors that drive joint activity participation. Moreover, modelling joint travel is important in its own right, as it allows for a much better understanding of traveler responses to the impacts of pricing policies and transit improvements than modelling household members completely independently. In our first attempt at a working model, we will assume that individual mandatory travel takes precedence over all other forms of household travel, including joint travel, though we certainly will leave open the possibility of modelling other travel sequences. To our knowledge this is the first attempt at modeling joint travel with European transport data, and it would be interesting to compare our results with those of other studies using North American travel data (see, for example, Gliebe and Koppelman, 2002, Bradley and Vovsha, 2005). Specifically, we will compare the nature of joint travel within the context of differing car ownership rates and transit facilities between London and typical North American cities. For the covering abstract see ITRD E137145.