Three gender-balanced groups of 16 school children (5-6 years, 8-9 years, 11-12 years) participated in individual pretests of vision, hearing, and time to walk across a 12-m wide urban street and back. Each child then completed 10 roadside trials requiring judgement of the threshold point at which they would no longer cross in front of traffic approaching from their right. The judgements were made from a site immediately in front of a parked car at a point 2 m from the kerb and 4 m from the centre of the road. Traffic speeds and distances were measured using a laser speed and distance detector. The results indicated that, overall, distance gap thresholds remained constant regardless of vehicle approach speeds. Analysis of the thresholds for distance gap judgements for the 4-m half-street crossing showed that some of the older children could be expected to make safe decisions, but this was not so for the 5-6- and 8-9-year-olds at vehicle approach speeds above 60 kph. Almost two-thirds of the children reported using distance to judge gaps, which proved the least adequate strategy in terms of proportion of resultant safe decisions. The findings are discussed in relation to developing effective child pedestrian safety strategies.