1 AN ANALYSIS OF TRIP CHAINING AMONG OLDER LONDON RESIDENTS Jan-Dirk Schmöcker a , Fengming Su b and Robert B. Noland c a Department of Civil and Environmental Engineering, Tokyo Institute of Technology, Japan b Institute of Comprehensive Transportation, Beijing, China c Alan M. Voorhees Transportation Center, Edward J. Bloustein School of Planning and Public Policy, Rutgers University, New Brunswick, US Keywords: Trip chaining, Older People, Tour Definition Abstract This paper examines the trip chaining complexity of individuals in London. We adopt two definitions of trip chaining. One based on a 30 minute dwell time rule and a second based on home-to-home tours. Our focus is on the complexity of the trip chains as measured by the number of stops on a given tour. The analysis uses the London Area Travel Survey and examines the factors associated with trip chaining for people aged over 65. A comparison with those aged under 65 reveals that older people on average make more complex tours when the 30 minute dwell time rule is applied as opposed to when the home-to-home definition is applied. It is further shown that the anchor points of the tour are critical for determining tour complexity, suggesting the usefulness of the 30 minute definition. Our analysis also suggests that older people reduce total home-to-home tours by combining different trips into single tours. Through descriptive analysis and ordered probit regression models we examine how reported levels of disability effect their trip chaining and we examine household demographic characteristics as well as proxies for accessibility, such as local population density. The analysis shows that disabilities do not necessarily lead to reduced tour complexity except when walking difficulties become so severe that independent travel is not possible. We suggest that tour complexity might further increase in the future, for example as the spread of mobile phone usage appears to have a further positive influence on tour complexity. Implications for land-use and transport planning are discussed. 1. Introduction The phenomena of trip chaining involves the linking together of trips, usually by car, such that activities are carried out at multiple destinations. Recent research, primarily in the US, has examined the growing propensity and increased complexity of trip-chaining behavior (McGuckin et al 2005, Noland and Thomas, 2007). As populations in most developed countries age, there is a question as to whether people will continue to engage in complex trip chaining, but more importantly, how the spatial distribution of activities may make this increasingly necessary. As the share of older people in the population increases, these questions are important to understand, not only for how travel behavior affects individual lifestyles, but to better plan for future travel patterns and the ability of the transport system to deliver the mobility that ageing individuals demand. Trip-chaining is often seen as a way to reduce the costs of travel, since activities can be more efficiently carried out when linked in sequence. This may be true especially of shopping trips,