Project exploring causes of glare experienced by drivers begins

A project has been launched to understand the factors that cause glare experienced by drivers and how to address them.

The AOP has welcomed the research but highlighted that broader work is needed in vision standards for driving.

Independent research consultancy, TRL, in partnership with the Department for Transport, will begin practical trials this month to assess the conditions that drivers describe as glare from oncoming headlights. The project will run into spring 2025.

TRL will instrument a car and use this to measure light levels experienced by motorists during real drives on UK roads.

Factors including weather conditions and ambient lighting will also be measured.

The consultancy suggested these measures will provide a “complete understanding of the conditions that are most likely to give rise to high brightness levels, and glare.”

A review of scientific evidence and stakeholder engagement will be undertaken to generate actionable recommendations for the Department of Transport to take forward in international working groups.

The RAC welcomed the project, with Rod Dennis, RAC road safety spokesperson, commenting: “We’re pleased to be contributing to this important piece of work that we very much hope will get to the bottom of the glare issue experienced by so many drivers up and down the country.”

In January, the RAC released the results of a survey of 2000 UK drivers, which found that 89% believe ‘at least some’ car headlights are too bright. Of drivers who expressed concerns, 91% said they are dazzled when driving, and three-quarters said this happens regularly. 

Discussing the new trials by TRL, Dennis said: “Our own long-term research shows that a significant proportion of the driving population struggles with dazzle, with some people reducing how much they drive, or even giving up driving at night altogether. Understanding what’s causing these problems, and most importantly what can be done about them in the future, will be a huge step forward for drivers.”

Welcoming the independent research, Adam Sampson, AOP chief executive, said: “We know from research that many drivers are increasingly worried about the effects of being dazzled by headlights while driving. As a keen advocate around vision and road safety in the UK, we are pleased to see that this issue is being taken seriously and the impact of LED headlights on road users is being investigated.”

The AOP suggested that this is a “singular issue in isolation” and that broader work is needed to improve road safety.

The association runs the annual public-facing Don’t swerve a sight test campaign to raise awareness of the need for regular sight tests and to call for a change in policy on vision standards for driving. 

“We have long argued that the way drivers’ vision is assessed needs to change,” Sampson said, pointing out that the number plate test cannot be considered a reliable indicator of whether someone can drive safely, as it does not check all relevant aspects of visual function.

He continued: “Many of our members raise very legitimate concerns over the number of patients they are seeing who fall below the required standard but continue to drive. With growing waiting lists for cataract operations and hospital eye appointments there is an added risk that we will see a growing number of these cases.”

“That is why we continue to call for a change to the law so regular vision checks are a mandatory part of licence application and renewal,” he said.