Daytime running lamp
[5] The daytime running light was first mandated, and safety benefits first perceived, in Scandinavian countries where it is persistently dark during the winter season.
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.
[10] For that reason, low-power solutions are being encouraged[11] and headlamp-based systems are not allowed after DRLs became mandatory in Europe at the beginning of 2011.
European Union Directive 2008/89/EC required all passenger cars and small delivery vans [14] first type[clarification needed][15] approved on or after 7 February 2011 in the EU to come equipped with daytime running lights.
[16][17][18] European Union Directive 2008/89/EC ended validity on 31 October 2014, implicitly repealed by the replacement Regulation (EC) No 661/2009.
Germany, Spain, France and other European countries have encouraged or required daytime use of low beam headlamps on certain roads at certain times of year; Ireland encourages the use of low beam headlights during the winter, Italy and Hungary require daytime running lamps outside populated areas, and Bulgaria, Czech Republic, Estonia, Kosovo, Latvia, Lithuania, North Macedonia, Montenegro, Poland, Romania, Serbia, Slovakia and Slovenia require the use of full or reduced voltage low beam headlights at all times.
DRLs were first mandated in the Nordic countries, where ambient light levels in the winter are generally low even during the day.
To increase manufacturer flexibility in complying with the requirement for DRLs, the daytime illumination of low beam headlights was added as an optional implementation.
Dim-dip was intended to provide a nighttime "town beam" with intensity between that of the parking lamps commonly used at the time by British drivers in city traffic after dark, and low beam headlamps; the former were considered insufficiently intense to provide improved conspicuity in conditions requiring it, while the latter were considered too glaring for safe use in built-up areas.
[27] In 1988, the European Commission successfully prosecuted the UK government in the European Court of Justice, arguing that the UK requirement for dim-dip was illegal under EC directives prohibiting member states from enacting vehicle lighting requirements not contained in pan-European EC directives.
Canada's proposed DRL regulation was essentially similar to regulations in place in Scandinavia, with an axial luminous intensity limit of 1,500 cd, but automakers claimed it was too expensive to add a new front lighting device, and would increase warranty costs (due to increased bulb replacements) to run the low beams.
[28] NHTSA objected on grounds of the potential for high-intensity DRLs to cause problems, such as glare and turn signal masking, and issued a proposed rule in 1991 that specified a maximum intensity of 2,600 cd.
[28] Industry and safety watchdogs reacted to the proposed rule,[28] and eventually the glare objections were set aside and most of the same types of DRLs allowed in Canada were permitted but not required effective with the 1995 model year.
[32] In denying the petition, the NHTSA said: [...] the agency remains neutral with respect to a policy regarding the inclusion of DRLs in vehicles [...] we do not find data that provides a definitive safety benefit that justifies Federal regulation [...] manufacturers should continue to make individual decisions regarding DRLs in their vehicles.
[32]Several states on the Eastern seaboard, the Southeast, Gulf Coast and California have laws that require headlights to be switched on when windshield wipers are in use.
