Brighter vehicle headlights are more likely to cause glare for oncoming drivers, a government-commissioned study has confirmed.
The research, conducted by consultancy TRL, found vehicle lighting to be a "genuine issue", with an RAC survey revealing 33 per cent of 1,850 UK drivers are now driving less at night or have stopped completely due to dazzling lights.
The study involved over 50 hours of on-road night-time testing.
A car equipped with a camera detecting headlight luminance – the amount of light being emitted – and other sensors recorded observations.
It found that observers were more likely to report glare from oncoming vehicles when higher luminance was recorded.
Other factors increasing glare included travelling uphill or around a right-hand bend, as a driver’s eyes are more likely to fall within the headlamps’ throw.
Researchers also noted a tentative indication that larger vehicle shapes, such as SUVs, may be more associated with glare.
A further 22 per cent of respondents said the issue means they would like to reduce their night driving but have no choice but to continue.
Dr Shaun Helman, who led the research at TRL, said: “This research provides compelling evidence that glare from vehicle lighting is a genuine issue for UK drivers, and can be measured in real driving conditions.
“By combining scientific measurement with driver perspectives, we now have a clearer understanding of the conditions under which glare occurs and the factors that contribute to it.
“These objective findings are a first step to take glare from anecdotal complaints into the realm of scientific evaluation.”
RAC senior policy officer Rod Dennis said: “Having campaigned hard for this study, we welcome its findings which independently confirm what drivers have been telling us – that rather than being an imagined phenomenon, some bright headlights do cause a glare problem.
“While drivers clearly benefit from high-performing headlights, it’s important this doesn’t lead to others suffering the effects of dazzle, so a balance needs to be struck.
“It’s vital the report and its considerations are now reviewed carefully to put us on a path towards changes that ultimately benefit all road users.”
A Department for Transport spokesperson said: “We know headlight glare is frustrating for many drivers, especially as the evenings get darker.
“That’s why we commissioned this independent research to better understand the causes and impact of glare, and to help inform future negotiations on international vehicle standards.
“Alongside this, DVSA (Driver and Vehicle Standards Agency) is stepping up surveillance to intercept the sale of illegal retrofit headlamp bulbs for on-road use, and anyone caught could face a fine of up to £2,500.”
