In a devastating split-second, the driver of a car doesn't see a bicycle, and the bicyclist doesn't see the car.
Warmer weather is only partially to blame for spring bicycle and pedestrian accidents.
Dusk and lack of awareness also make bikes and walkers harder to see and easier to hit. Warmth draws people out onto the streets and sidewalks. One bicyclist struck a parked car and the other left the sidewalk and was struck by a car. Police cited both bicyclists for their roles in the accidents. Both cases, O'Brien believes, easily could have been prevented.