Riders cycling on roads without bicycle lanes are generally advised to ride in the centre of their lane (primary position), and to move toward the left of the lane (in left-hand traffic; secondary position) only to let faster traffic pass and when it is safe. The present research investigated which situational and personal characteristics were associated with choice of lane position, and whether choice of lane position is associated with on-road crash involvement. A large cohort of bicycle riders from New South Wales Australia reported on their cycling patterns and crashes in 6 reporting weeks over a 1-year period using on-line surveys. During one reporting week 1525 participants identified their preferred choice of lane position in each of 6 visually-depicted scenarios that were designed to investigate the influence of number of lanes (in the cyclists’ direction of travel), parked cars, and bus lanes. A majority of respondents preferred the secondary position in scenarios with a clear kerbside lane. Respondents were significantly more likely to choose the primary position in multiple-lane situations compared to single-lane situations, if there were parked cars in the kerbside lane, and if they were female, younger, experienced riders, transport riders, or high intensity riders. Controlling for personal characteristics, choosing the primary position in a single clear traffic lane scenario was associated with a higher on-road crash rate, while choosing the primary position in a traffic lane with parked cars scenario was associated with a lower on-road crash rate. Results suggested that when riding on-road the bicycle riders in this Australian cohort prefer to keep their distance from motorised traffic, allowing traffic to pass safely when space allows. Nonetheless, results suggested that choice of lane position is highly dependent on the local road and traffic environment. Further research is needed to support advice to cyclists.