This paper examines mode choice variation in the Netherlands based on the trip data of 432 respondents from a four-week smartphone-based travel survey. Trip characteristics, including origin and destination location, arrival and departure time, mode and trip purpose, were automatically recorded, but checked and if necessary revised in a web-based prompted recall survey. Statistical analyses and mixed logit mode choice models were used to explore intrapersonal variation and its effect on mode choice. We found relatively much intrapersonal variation for short trips (<2 km) as respondents who usually travel by car also regularly walk and/or cycle. By contrast, intrapersonal variation was significantly smaller in trips longer than 10 km, suggesting that people choose the same mode when they repeat long journeys. The intrapersonal variation is also relatively small for commute trips, implying a high level of habituation. In addition, the results from the mixed logit mode choice models clearly show that including a classification of travellers determined by the degree of intrapersonal variation significantly explains mode choice.