Visible distances and safe approach speeds for night driving.

Abstract The purpose of this investigation was to demonstrate the visible distances that can be considered realistic during night driving on non-illuminated roads. From the experimental data the approach speeds were calculated that can be considered as safe for various conditions and states of the driver, the car and the road. 413 drivers volunteered to participate in their own oars in 14 different places in Sweden. Each driver's task was to drive his ear towards a stationary car, both cars with dipped headlights, and to brake as soon as he was aware of a dark-clothed dummy that was placed in the middle of the lane beside the stationary car. A special experiment compared the results of this semi-dynamic test with those of a fully dynamic test. The median visible distance was 23 m and the 10th percentile 15 m. The calculated safe approach speeds for the tested drivers varied between 25 km/ h and 50 km/ h depending on the conditions chosen. A simplified parallel investigation with 974 participating drivers ...