One study found that in good conditions the 95th percentile reaction time is 1.6 seconds while the 50th percentile is 1.1 seconds. On a dry roadway, it takes about 330 feet to stop a car going 55 mph and about 174 feet to stop a car travelling at 35 mph. A pedestrian wearing dark clothing is only visible at a distance of 100 feet at night to a driver using low beams. Pedestrian behavior often contributes to accidents. Moreover, an inordinate percentage of struck pedestrians are under the influence of alcohol.
Drivers are poor at estimating roadway curves.
They almost always underestimate the amount of curvature. Peoples' motion perception is highly inaccurate under some conditions. Drivers tend to overestimate the speed of slow moving vehicles and underestimate the speed of fast ones. Perception of motion in cars immediately in front and behind is especially poor. It is difficult to tell,for example, that the car in front of you is stopped rather than moving.