Daytime running lights: a warning
· By: Dan Keegan
· Date: 1990-09-09
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As more cars use daytime running lights, the risk to drivers not using them will steadily increase, according to Transport Canada studies. Starting with the 1990 model-year, all cars sold in Canada must have Daytime Running Lights (DRLs).
The effectiveness of daytime lights in reducing accidents has been proven by research in a number of countries, including Canada, the USA, Finland, and Sweden. The systems have been shown to reduce multiple vehicle collisions by as much as 32 per cent. Finland was the first to make their use mandatory in 1972. Sweden followed suit in 1977.
But Transport Canada's research into the use of daytime lights showed another effect, one that will become more important as daytime running lights become a standard part of the driving scene. Drivers who don't have daytime running lights run a risk of being "masked" by drivers who do. Research carried out for Transport Canada in the mid-'70s by Dr. Dennis Atwood, showed that drivers meeting a line of cars in a passing situation were more likely to miss an oncoming car without headlights if it were surrounded by cars that had headlights on.
Atwood's results played a large part in the change in Ontario's traffic laws requiring automobile headlights to be switched on one hour earlier in the evening and switched off one hour later in the morning.
The masking effect, which Atwood attributed to either the glare or the distraction effect of the headlights (or a combination of both) was strongest at dawn and dusk and increase rapidly as the level of light dropped off. At sunset, the light level can drop by a factor of 10 in as little as 10 minutes, he says, and the risk increases rapidly for drivers not switching on their headlights.
Atwood believes that as a greater proportion of drivers begin using daytime running lights, the danger of masking will increase for those left without them.
Daytime running light systems have a lower intensity than low beam headlights and last longer with less energy use.
While the biggest advantage of the systems is when natural light is low, such as at dusk or dawn or when skies are overcast, research indicates that they are also an advantage even on bright, sunny days. Because the human eye is light-seeking, drivers will see an oncoming car sooner and make a more accurate estimate of its rate of approach.
The effect is particularly important for peripheral vision, which may not see an object at all unless it contrasts sharply with its background or moves against it. Using daytime lights significantly reduces the chances of a car, cyclist or pedestrian moving unexpectedly into your path.
Atwood suggests that drivers of cars that don't have daytime running lights
as a standard feature purchase a retrofit kit rather than using low beams.
