Автор: batonga
Дата: 07-08-12 12:43
Safety performance
A 2008 study by the U.S. 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 safety benefit produced by DRLs in relatively dark Nordic countries is roughly triple the benefit observed in relatively bright Israel and America.
Environmental impact
DRL power consumption varies widely depending on the implementation. Current production DRL systems consume from 8 watts (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 when DRLs become mandatory in Europe at the beginning of 2011. LEDs and low-power, high-efficacy, long-life light bulbs produce appropriate amounts of light for an effective DRL without significantly increasing fuel consumption or emissions. Fuel consumption reductions of up to 0.5 mpg may be found when comparing a 55 W DRL system to a 200 W DRL system. In 2006, the UK's Department of Transport also found significant reductions in emissions and fuel consumption when comparing a 42 W DRL system to a 160 W full headlight DRL systems. DRL fuel consumption can be reduced to insignificant levels by the use of 8 to 20 W DRL systems based on LEDs or high-efficacy filament bulbs.
European Union
European Union Directive 2008/89/EC requires all passenger cars and small delivery vans first type approved on or after 7 February 2011 in the EU to come equipped with daytime running lights. The mandate will extend to trucks and buses in August 2012. Functional piggybacking, such as operating the headlamps or front turn signals or fog lamps as DRLs, is not permitted; the EU Directive requires functionally specific daytime running lamps compliant with ECE Regulation 87 and mounted to the vehicle in accord with ECE Regulation 48. DRLs compliant with R87 emit white light of between 400 and 1200 candela.
Info: Wikipedia
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