This paper attempts to understand mode choice decisions among older and disabled people in London, with the objective of determining what policies can best meet their mobility and activity needs. A literature review is followed by a description of the data sets and modelling methods used in this analysis. Two assumptions are made on the marginal costs of car usage and it is shown that large investments (car, travelcards) are not amortized in the mode choice decisions made, but that marginal costs need to be appropriately specified. Age and disability interactions are shown to influence public transport use with those with disabilities preferring not to use public transport, although if healthy, older people will use buses and trams. The preference for taxis also increases with age when there is a disability. Public transport accessibility measures were also found to be associated with increased public transport use