Auto racing has recently become a popular nighttime spectator sport. Proper illumination must consider the safety requirements of the drivers as well as the enjoyment of the spectators. Floodlights mounted in the grandstand reduce pole count and should be aimed in the direction of travel to minimize glare for the drivers. Within the track, various mounting heights and pole placements are necessary due to track configuration. Technical specifications are below.
Track Class Designations
- Class II – Facility with LARGE spectator capacity
- Class III – Facility with SOME spectator capacity
- Horizontal illuminance – a measure of the lumens per unit area on a horizontal surface. Normally it is measured three feet above the driving surface.
- Uniformity illuminance – a measure of the rate of change of illuminance expressed as a ratio between the illuminance level of adjacent measuring points on a uniform grid. The limit of uniformity varies with the speed of the ball.
- LUX – a measure of illuminance weighted to the spectral sensitivity of the human eye. It is defined as 1 lux = 1 lumen/square meter.
- FC – foot-candle. The official definition is 1 foot-candle = 10.764 lux, however it is easiest to approximate at 1 foot-candle ≈ 10 lux.