Automatic Headlights Vs. Daytime Running Lightsby Andrea Stein
Headlights refer to lamps that attach to the front of a vehicle and provide illumination during periods of low visibility. Standard headlights operate via an on/off switch controlled by the driver. Automatic headlights and daytime running lights both offer automatic function, but vary in operation and results.
Automatic headlights automatically switch on or off based on sensors that determine the level of sunlight. Once natural light dims to a certain level, automatic headlights switch on to compensate. Daytime running lights refer to lighting devices on automobiles that switch on automatically when a vehicle moves forward.
Automatic headlights offer standard headlight illumination once switched on. Daytime running lights often operate at a dimmer level of illumination than offered by standard headlights, no matter the level of ambient light.
Daytime running lights offer no operator control and, therefore, cannot be turned off if they glare into another vehicle, into a house or at a pedestrian. Operators with daytime running lights may not remember to turn on their headlamps at dusk, potentially leading to hazardous driving conditions due to reduced visibility. Automatic headlights can switch on during times of high visibility if the sensor, typically located between the rear view mirror and windscreen, falls under shade or is otherwise blocked from sunlight.
- Insurance Institute for Highway Safety: Q & As: Daytime Running Lights
- "Car Science"; Richard Hammond; 2008