Question of the week: Why are so many cars using headlights during the day?
Fri, 06 Dec 2024
Dear Honest John,
"It's 3pm, a grey day with a little rain. Visibility is still good and I can see a few miles in all directions. Sidelight weather, to make me a bit more visible.
Now I have to slow right down because some idiot is in the middle of the road with full headlights and one fog light dazzling my vision. Hang on they are turning right. The lights are so bright you can't see the indicator hidden in the glare. It also seems like 90% of other drivers have all switched to full headlights and the glare is unbearable, especially as it is doubly bright and reflected from the wet road surface!
After over 40 years of driving experience, I cannot see this scenario ending well. I use headlights to see in the dark, sidelights to make my car more visible in situations like today and fog lights for fog. What legislation has led to this ridiculous situation on our roads? And please tell me why don't automatic headlights start by switching on sidelights if it's a bit grey?"
- MM
Dear MM,
Lighting technology has improved immeasurably in recent years with halogen bulbs being phased out in favour of xenon, the introduction of daytime running lights and more recently LED technology.
Generally speaking the legislation has not changed significantly, but it is likely that the increased number of vehicles fitted with automatic headlights and vehicles that automatically switch off headlights when the vehicle is turned off means some drivers simply leave the switch on the automatic or headlight setting at all times. The result is that more vehicles have headlights on more of the time.
The Highway Code makes two important points in this respect. Rule 226 states 'You MUST use headlights when visibility is seriously reduced, generally when you cannot see for more than 100 metres (328 feet).'
The term 'generally' allows some room for interpretation, but it could be argued that rain, overcast skies, mist or fog would qualify. And in the winter months when the daylight hours are significantly reduced it is understandable that drivers use headlights most or all of the time.
Rule 114 states 'You MUST NOT use any lights in a way which would dazzle or cause discomfort to other road users, including pedestrians, cyclists and horse riders.' A correctly adjusted headlight should not dazzle, but an uneven road surface or the angle at which a vehicle is facing in respect of other traffic may cause temporary dazzle.
The use of sidelights is also mandatory between sunset and sunrise, but on vehicles fitted with automatic headlights the window between sidelights and headlights will be comparatively small and will depend on the sensitivity of the system.
Research has shown that using headlights during the day can reduce incidences of two-vehicle crashes by 5.7%, the reduction of pedestrian accidents by 12% and a 23% reduction in motorcycle accidents involving vehicles coming from the other direction, so while the issue of dazzle is one that has been raised in parliament, there are safety benefits to the regular use of headlights outside of nightime hours.
How can I improve my visibility on the road?
