Our sample worked in the city of Cambridge, UK, and lived within a 30 km radius of the centre. Therefore the findings may not be
representative of other areas or of the general population living in the study area. However, commuting is a widespread behaviour with
the same common aim and it may be possible to overcome any generalisability limitations by taking into account other factors that may
influence commuting behaviour in a particular area. For example, topology may be important if the location is particularly hilly.