Effects of Different Factors on Visual Cognition Distance of Drivers at Night

While driving at night,drivers' perception distance would be affected by some hidden factors in the driver-vehicle-road system. In order to study the influence,35 subjects were selected to participate in the actual road tests,obstacles were respectively black and white,and test roads were respectively black asphalt pavement and white cement road surface. Under condition of different speeds and different cabin environmental luminosities,calibration tests on obstacles perception distance were carried out. The variation law of perception distance was analyzed through trimming all the test results and statistical testing of impact induced by different factors. Results show that vehicle speed,environmental luminosity in cabin and obstacles' color have a significant influence on the driver's perception distance at night,that influence of contrast between road environment colors is not significant,that for driving at night,environmental luminosity in cabin should be reduced to improve color visibility of other factors on road to improve driving safety,and that driving speed should be reduced appropriately to meet condition that perception distance became smaller.