Should I walk, cycle or drive? Active-to-passive travel directness and mode choice across 15 months of GPS-traced trips

Improving active travel infrastructure may not substantially increase cycling and walking if motorised transport continues to be largely perceived as the easier and more convenient option. Here, we develop a measure of comparative directness, Active-to-Passive Travel Directness (APTD), and assess it as a predictor of mode choice among those using cycling, walking and motorised transport in their daily travels. We leverage 15 months of GPS data in Gävle municipality, Sweden, to derive bicycle, walking and motor vehicle trips (N=13,058 trips from 121 travellers) and estimate associations between the trip-level APTD and mode choice. The length of the shortest active travel route to a destination was negatively associated with the likelihood of cycling (per km, relative risk ratio (RRR) = 0.78 [0.76, 0.80]) as well as walking (per km, RRR = 0.29 [0.27, 0.31]). In addition, a higher APTD was strongly associated with a higher likelihood of cycling or walking. For example, at a shortest active travel route of 3 km, the probability of cycling ranged from 14.2 % to 28.8 %, when comparing across the observed range of APTD values. Moderation analyses revealed no significant interactions between APTD and either sex or season for any mode outcome, suggesting that the…