Cabecera ciencia en ingles

Martes, 29 de Marzo de 2011

Daytime-running lights in cars affect pedestrians’ reaction to turn signals

Researchers at the University of Granada have proved that keeping lights on all day –as most of European authorities recommend- introduce ambiguity into the turn signal system. Daytime-running lights (DRL) will become mandatory to all vehicles –they were optional up to now- manufactured in Europe from 2011

Driving with the car lights on in day time slows down pedestrians’ reaction to turn signals, a study conducted at the Civil Engineering Department of the University of Granada reveals.

The advantages of installing DRLs in passenger vehicles have been proved by a number of studies. Some of such studies estimated that DRLs could prevent between 5 and 15% of running overs. The conclusions obtained in these studies have prompted European authorities to make the decision of making DRLs mandatory in all passenger vehicles manufactured in Europe from 2011.

This study was conducted by professor Antonio Peña García and has counted on the participation of professors Juan de Oña López, Antonio Espín Estrella, Fernando Aznar Dols, Francisco Javier Calvo Poyo, Rocío de Oña López and Evaristo Molero Mesa.

Seeking Drawbacks

Researchers wanted to know whether DRLs presented any drawback as masking turn signals, which function is to give notice about the driver’s intention to turn. They also posed the question whether the European requirement of DRLs being white is beneficial or not, as compared with the situation in the USA, where DRLs can be white or amber.

For the purpose of this study, researchers designed an experiment where they measured the visual reaction times of 148 observers to turn signals under different situations that involved the presence of DRLs. Measurements were taken in outer spaces with natural light, with the purpose of reproducing the real conditions where running overs usually occur at daytime, which is the when DRLs are on.

The conclusions obtained proved that DRLs color and the angle of perception affect directly pedestrians’ reaction time to turn signals. However, the distance between turn signal lamps and DRLs –which is a controversial issue in the EU– did not offer statistically-significant results.

The results obtained in this study were published in the October 2010 issue (Vol.41, No 5) of Journal of Safety Research, and are available at

Contact: Prof. Antonio Peña García- Dpt. Civil Engineering of the University of Granada. Phone Number: +34 958 249 435. E-mail address: