ANCAP is considering encouraging the uptake of daytime running lights (on cars) through the Safety Assist Technology (SAT) component of its Road Map (see http://www-nrd.nhtsa.dot.gov/pdf/esv/esv22/22ESV-000106.pdf for a description of the Road Map)
I am looking for recent studies on the effectiveness of DRLs - particularly the dedicated bright white ones now required on cars under European regulations.

Now that DRLs are mandatory for cars in Europe I was wondering if anyone is monitoring the effectiveness on a model-by-model basis? That is, where the only significant change to a model has been the addition of dedicated DRLs, has there been a change in accident rates? It would be very useful if such analyses included more southern nations like Spain.

General Motors did this type of study in the 1990s when they decided to make DRLs standard on all cars sold in the USA. This SAE paper has the details:
SAE Paper 2003-01-2072
Daytime Running Lamps (DRLs) for Pedestrian Protection
by Paul Thompson from General Motors.

That study found that, nationally, the GM-style dedicated white DRLs reduced car-to-car collisions by 9% (daytime multi-vehicle collisions). It was further estimated that pedestrian collisions were reduced by as much as 15%. Importantly the GM study included the "sunny" states like Texas, New Mexico and Florida, although individual results by US state are not presented.

The GM study found different effectiveness with various styles of DRL. I have plotted the findings against the estimated signal range for each type of DRL - see the attached graph. My own research between 2003 and 2005 identified that low beam headlights are only marginally effective as DRLS on bright cloudy days and that this could account for the so-called latitude effect noted in some early studies of DRLs (that were mostly based on low-beam headlights):
http://www-nrd.nhtsa.dot.gov/pdf/nrd-01/esv/esv19/05-0178-W.pdf
and http://users.tpg.com.au/mpaine/drl.html

Suggestions for people in Europe that I could contact about this would be appreciated.

Regards

Michael Paine
Technical Manager ANCAP
================================
ANCAP http://www.ancap.com.au
PO Box 4041 Manuka ACT Australia 2603
ACT Office Tel +61 2 6232 0232
Audio and Video conferencing iChat / Windows AIM 6.1 / Skype