Table 9 Difference between the average speed in different light conditions (darkness, twilight) and the average speed in daylight for the same road, month, and weather condition (clear, rain, snow)
From: Effects of weather conditions, light conditions, and road lighting on vehicle speed
Weather | Light cond. | Road lighting | Speed − speed in daylight |
|---|---|---|---|
Clear | Darkness | No lighting | 1.0 |
Rain | Darkness | No lighting | −0.9 |
Snow | Darkness | No lighting | −3.5 |
Clear | Twilight | No lighting | 1.2 |
Rain | Twilight | No lighting | −0.2 |
Snow | Twilight | No lighting | −1.2 |
Clear | Darkness | Lighting | 1.1 |
Rain | Darkness | Lighting | 0.6 |
Snow | Darkness | Lighting | 0.2 |
Clear | Twilight | Lighting | 0.8 |
Rain | Twilight | Lighting | 0.4 |
Snow | Twilight | Lighting | −0.3 |