Исследование
Daytime Running Lights (DRL): A review of the reports from the European Commission / October 2006
Выводы
8 Conclusions1. There is substantial evidence that the mandatory use of DRL would provide a net accident reduction. However, the evidence concerning the magnitude of the effect and particularly the relationship with accident severity is considerably weaker.
2. The estimates of the fuel and emissions increases as a result of implementing DRL are reasonable and possibly slightly conservative (high).
3. The research into the potential of DRL on cars to impair the conspicuity of motorcyclists and other vulnerable road users was well controlled but limited in scope and did not consider some important variables. However, when compared with other similar studies some consistent conclusions could be drawn. These were that it should be possible to design dedicated DRL of low intensity that are beneficial to the conspicuity of cars without adversely affecting the conspicuity of motorcyclists. However, DRL of higher intensity (potentially including standard passing beam headlights) could have an adverse effect on motorcyclist conspicuity in some circumstances.
4. There is considerable scientific uncertainty inherent in the values of the benefit to cost ratios presented in the EC work. The key variable is the assumption that the accident benefits would be considerably greater for fatal accidents (15%) than for serious (10%) or slight (5%) accidents. This assumption was very weakly supported by the available data and changing it to a more technically defensible assumption that the mean effect of 5.9% remained the same for all accident severities reduced the benefit to cost ratios to much less than 1.
5. It was considered that it would be more technically valid to present a range of possible benefit to cost ratios within which there could be confidence that the true answer would lie, thus reflecting the technical uncertainty. The analysis showed that a ratio of 1 would fall within this range meaning that, although an accident reduction potential exists, it is not possible to say with certainty whether the benefits of implementing DRL would outweigh the costs.
Что в переводе означает
1. Принудительное введение DRL однозначно снижает аварийность
2. Рассчетная оценка выброса вредных газов приемлима, хоть при этом оценка слишком завышена
3. Исследование не включало в себя полную оценку влияния на видимость мотоциклистов и прочих уязвимых участников дорожного движения, Но высказывается некоторое предположение что возможно в некоторых случаях использование DRL высокой яркости, либо обычных фар в их качестве как-то может на повлиять. Но точного ответа данное исследование не дает.
4. Наиболее важный результат данного исследования в том что DRL дает снижение аварийности лишь на 5.9% независимо от тяжести, а не 15%/10%/5% как предполагалось ранее
5. Данное исследование показало что отношение затрат к полезному эффекту близко к единице. Потенциал по снижению есть, хотя и нельзя сказать с уверенностью что затраты окупятся
и даже днем 
Неумеренность бывает еще хуже чем недостаток. 
Следуя этой логике, чтоб тебя было хорошо видно нужно включить габариты + ЗПТФ + задний ход, так? 
