The purpose with this investigation was to demonstrate the visible distances that can be considered realistic during night driving car-meetings on non-illuminated roads. From the experimental data were calculated the meeting speeds that can be considered as safe during various conditions and states of the driver, the car and the road. 413 drivers volunteered to participate in their own cars in 14 different places in Sweden. Each driver's task was to drive his car towards a stationary car,both cars with dipped headlights, and to brake as soon as he discovered a dark clothed dummy that was placed in the middle of the lane beside the meeting car. A special experiment compared the results of this semidynamic test with those of a fully dynamic test. The median visible distance was 23 m and the 10th percentile 15 m. The calculated safe meeting speeds for the tested drivers varied between 25 km/h and 50km/h depending on the conditions chosen. A simplified parallel investigation with 974 participating drivers did not show any marked divergences.
Abstract