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Daytime running lamp
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Daytime running lamp
A daytime running lamp (DRL, also daytime running light) is an automotive lighting and bicycle lighting device on the front of a road going motor vehicle or bicycle. It is automatically switched on when the vehicle's handbrake has been pulled down, when the vehicle is in gear, or when the engine is started, emitting white, yellow, or amber light. Their intended use is not to help the driver see the road or their surroundings, but to help other road users identify an active vehicle.
Depending on prevailing regulations and equipment, vehicles may implement the daytime-running light function by functionally turning on specific lamps, by operating low-beam headlamps or fog lamps at full or reduced intensity, by operating high-beam headlamps at reduced intensity, or by steady-burning operation of the front turn signals. Compared to any mode of headlamp operation to produce the daytime running light, functionally dedicated DRLs maximize the potential benefits in safety performance, glare, motorcycle masking, and other potential drawbacks.
A daytime running lamp is usually automatically switched on once the ignition is on; other vehicles may switch the daytime running lamps on when the parking brake is released or when the vehicle is shifted into gear. A daytime running lamp emits a brighter light when the headlamps are not turned on and its brightness will be dimmed slightly in conjunction with the headlamps being turned on.
A 2008 study by the US National Highway Traffic Safety Administration analysed the effect of DRLs on frontal and side-on crashes between two vehicles and on vehicle collisions with pedestrians, cyclists, and motorcyclists. The analysis determined that DRLs offer no statistically significant reduction in the frequency or severity of the collisions studied, except for a reduction in light trucks' and vans' involvement in two-vehicle crashes by a statistically significant 5.7%.
The daytime running light was first mandated, and safety benefits first perceived, in Scandinavian countries where it is persistently dark during the winter season. As ambient light levels increase, the potential safety benefit decreases while the DRL intensity required for a safety improvement increases. The safety benefit produced by DRLs in relatively dark Nordic countries is roughly triple the benefit observed in the relatively bright United States.
A number of motorcycling advocacy groups are concerned over reduced motorcycle conspicuousness and increased vulnerability with the introduction of headlamp-based DRLs on cars and other dual-track vehicles, since it means motorcycles are no longer the only vehicles displaying headlamps during the day. Some researchers have suggested that amber DRLs be reserved for use exclusively on motorcycles, in countries where amber is not presently a permissible color for DRLs on any vehicles, while other research has concluded there is a safety disadvantage to two 90 mm (3+1⁄2 in) × 520-candela DRLs on motorcycles in comparison to one 190 mm (7+1⁄2 in) × 270-candela dipped (low) beam headlight. The latter result suggests that a daytime running lamp's luminous area may have an important influence on its effectiveness.
DRL power consumption varies widely depending on the implementation. Current production DRL systems consume from 5 W (dedicated LED system) to over 200 W (headlamps and all parking, tail, and marker lights on). International regulators, primarily in Europe, are working to balance the potential safety benefit offered by DRL with the increased fuel consumption due to their use.
Because the power to run the DRLs must be produced by the engine, which in turn requires burning additional fuel, high-power DRL systems increase CO2 emissions sufficiently to affect a country's compliance with the Kyoto protocol on greenhouse gas emissions. For that reason, low-power solutions are being encouraged and headlamp-based systems are not allowed after DRLs became mandatory in Europe at the beginning of 2011.
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Daytime running lamp AI simulator
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Daytime running lamp
A daytime running lamp (DRL, also daytime running light) is an automotive lighting and bicycle lighting device on the front of a road going motor vehicle or bicycle. It is automatically switched on when the vehicle's handbrake has been pulled down, when the vehicle is in gear, or when the engine is started, emitting white, yellow, or amber light. Their intended use is not to help the driver see the road or their surroundings, but to help other road users identify an active vehicle.
Depending on prevailing regulations and equipment, vehicles may implement the daytime-running light function by functionally turning on specific lamps, by operating low-beam headlamps or fog lamps at full or reduced intensity, by operating high-beam headlamps at reduced intensity, or by steady-burning operation of the front turn signals. Compared to any mode of headlamp operation to produce the daytime running light, functionally dedicated DRLs maximize the potential benefits in safety performance, glare, motorcycle masking, and other potential drawbacks.
A daytime running lamp is usually automatically switched on once the ignition is on; other vehicles may switch the daytime running lamps on when the parking brake is released or when the vehicle is shifted into gear. A daytime running lamp emits a brighter light when the headlamps are not turned on and its brightness will be dimmed slightly in conjunction with the headlamps being turned on.
A 2008 study by the US National Highway Traffic Safety Administration analysed the effect of DRLs on frontal and side-on crashes between two vehicles and on vehicle collisions with pedestrians, cyclists, and motorcyclists. The analysis determined that DRLs offer no statistically significant reduction in the frequency or severity of the collisions studied, except for a reduction in light trucks' and vans' involvement in two-vehicle crashes by a statistically significant 5.7%.
The daytime running light was first mandated, and safety benefits first perceived, in Scandinavian countries where it is persistently dark during the winter season. As ambient light levels increase, the potential safety benefit decreases while the DRL intensity required for a safety improvement increases. The safety benefit produced by DRLs in relatively dark Nordic countries is roughly triple the benefit observed in the relatively bright United States.
A number of motorcycling advocacy groups are concerned over reduced motorcycle conspicuousness and increased vulnerability with the introduction of headlamp-based DRLs on cars and other dual-track vehicles, since it means motorcycles are no longer the only vehicles displaying headlamps during the day. Some researchers have suggested that amber DRLs be reserved for use exclusively on motorcycles, in countries where amber is not presently a permissible color for DRLs on any vehicles, while other research has concluded there is a safety disadvantage to two 90 mm (3+1⁄2 in) × 520-candela DRLs on motorcycles in comparison to one 190 mm (7+1⁄2 in) × 270-candela dipped (low) beam headlight. The latter result suggests that a daytime running lamp's luminous area may have an important influence on its effectiveness.
DRL power consumption varies widely depending on the implementation. Current production DRL systems consume from 5 W (dedicated LED system) to over 200 W (headlamps and all parking, tail, and marker lights on). International regulators, primarily in Europe, are working to balance the potential safety benefit offered by DRL with the increased fuel consumption due to their use.
Because the power to run the DRLs must be produced by the engine, which in turn requires burning additional fuel, high-power DRL systems increase CO2 emissions sufficiently to affect a country's compliance with the Kyoto protocol on greenhouse gas emissions. For that reason, low-power solutions are being encouraged and headlamp-based systems are not allowed after DRLs became mandatory in Europe at the beginning of 2011.
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