Overly bright vehicle headlights ARE dazzling drivers, government-funded study finds

The government has been advised to review and update headlight standards to reduce headlight glare following a major probe into the cause of driver dazzling.

Findings by TRL (Transport Research Laboratory) have identified the causes of glare from vehicle lights, and how badly this is impacting drivers.

The research – which combined on-road data alongside an RAC survey of a nationally representative sample of 1,850 UK drivers – concluded that glare can be objectively linked to bright headlights, and to certain road conditions and vehicles. 

The study, funded by the Department for Transport (DfT), comes in response to growing concern about the perceived dangers from headlights. 

An RAC survey revealed four in five drivers fear being dazzled by them at night, and on average each year police are called to 280 collisions and six fatal collisions where headlight glare is cited as having played a role in causing the accident.

A debate took part in parliament last week on the matter, and the potential merits of a new standard for vehicle headlight glare were argued for.

So, could there be a crackdown on car makers and headlight bulb producers imminent? 

A DfT funded TRL study has identified the causes of glare from vehicle lighting on British roads, and how glare from these affects drivers – and bright have now been blamed for dazzling motorists

Key findings from the TRL study show that drivers perceived modern vehicle headlights to be ‘too bright’, with whiter lights and those fitted to taller vehicles such as SUVs often cited as problematic.

To gather the information, over 50 hours of on-road testing was conducted in a car instrumented with a luminance camera and other sensors.

A strong link between higher levels of luminance and glare experienced by observers inside the vehicle was identified – and the pitch and roll of the instrumented car was shown to increase the likelihood of glare being experienced.

Factors outside the control of the DfT were also discovered to have an impact on glare, including different vehicles and road geometrics, such as hills and bends.

These factors aside, the study suggests that vehicle design and updated vehicle lighting standards would play a significant role in mitigating the problem for the nation’s motorists.

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.’

A DfT spokesperson responding to the findings told the Daily Mail and This is Money: ‘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.’

The study suggests that vehicle design and updated vehicle lighting standards could play a role in mitigating the problem

22% of people told the RAC that they’d like to drive less at night because of headlight glare but have no option

How should the government and industry intervene to help reduce headlight glare?

TRL has proposed several considerations for government and industry in order to make motorists less anxious about being temporarily blinded by oncoming vehicles.

TRL’s proposals range from harvesting data and raising public awareness to changing car design features to practically remove glare.

Government and industry are being advised to review and update vehicle lighting standards to better reflect real-world conditions and the impact on drivers. 

This includes adjusting requirements to limit ‘luminance’ rather than ‘luminous intensity’. 

Luminous intensity refers to the overall brightness of the headlights, while luminance indicates the degree of brightness over an area – the greater the source area the higher the luminance.

It’s also been suggested that further research into vehicle design features such as novel LED headlamps and vehicle height is conducted.

Highlighting the importance of gathering motorist viewpoints, TLR has proposed running public information campaigns to help drivers better understand risks from glare and suggest the things they can do to make driving at night less stressful.

And to establish regular national surveys to monitor trends in drivers’ experiences of glare.

Are poor quality headlight bulbs causing glare?

The presence of non road legal headlight bulbs on the road may be the major cause of dazzling.

New insight from bulb manufacturer Osram has found that there’s been a distinct rise in poor quality halogen bulbs on the market that it says fail to meet the legal minimum standard. 

As a result, they could be causing the glare on the roads that so many drivers are struggling with.

Osram’s laboratory team tested other automotive lighting company products, as well as their own, to ensure legal standards are met and for quality checks.

Worryingly, the company has recently found that bulbs are being sold in the UK that aren’t compliant with current legislation, and therefore not road legal. 

Bulbs need to comply to ECE Regulation 37 that details light output and minimum and maximum levels and voltage, among other specifications, so drivers can see safely and other road users aren’t dazzled. 

Multiple bulbs were tested from the same brands to ensure consistency, but there were still concerning finds. 

One company’s bulbs all exceed the maximum wattage and lumen levels by a considerable margin. Another was more than 26 per cent above the maximum lumen output, and wattage was 49 per cent above the max.

Other bulbs showed signs of deterioration after only a few minutes. Some had a poor beam pattern which causes glare.

And many bulbs simply didn’t confirm with ECE Regulation 37, and therefore were not road legal.

Osram has recently tested a number of car headlight bulbs with some concerning findings 

What’s next for the headlight glare campaign? 

The government is currently reviewing the findings, while ongoing debates around the subject and campaigning takes place.

The DfT has said it plans to build on its real-world research work with further targeted vehicle-based research to help inform future international lighting regulations.

And that it is preparing to introduce the first road safety strategy in over a decade, and next steps will be set out in due course.

A DfT spokesperson told the Daily Mail and This is Money: ‘The DVSA 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.’ 

TRL’s Dr Helman added: ‘These objective findings are a first step to take glare from anecdotal complaints into the realm of scientific evaluation. 

‘Continued research will help inform UK road safety and transport policy. The long-term goal is to improve public confidence and safety when driving at night.’

RAC senior policy officer Rod Dennis commented on the 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.

‘We don’t yet have all the answers, but this report undoubtedly helps moves us towards tackling the complex problem of glare from vehicle headlights. 

‘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.’

Seven ways to limit the impact of glare – and prevent dazzling others 

1. Slow down at night

If the glare from an oncoming vehicle at night is so bad that you temporarily can’t see anything, you should slow down to reduce the risk of the impact on your impaired visibility.

However, avoid slowing or stopping abruptly as you don’t want a car that is travelling behind you running into the back of you. 

2. Don’t look directly at oncoming headlights

To prevent yourself from being dazzled, never look directly at the headlights of other cars.

Look to the left-hand side of the road and follow the white line marking the edge if there is one, so you can keep track of your position, the RAC recommends. 

3. Make sure your windscreen is clear 

Windscreens are particularly susceptible to steaming up on the inside, especially in cold weather, while car heaters can blow dirty air at the glass, causing a hazy film to build up on the inside. 

This can increase glare from oncoming headlamps, so ensure yours is clean and clear.

4. Adjust your rear-view mirror 

Drivers at night should dip the rear-view mirror to reduce the risk of being dazzled by motorists following them.

Many new motors in showrooms today have an auto-dimming rear-view mirror function. If your car doesn’t then you should be dipping the mirror manually.

5. Consider anti-glare glasses

If being dazzled by other drivers’ headlights or street lighting is an issue, motorists should consider anti-glare glasses when driving at night.

These are not simply glasses with yellow tints, which can help reduce glare by also make darker areas of the road less visible and are therefore not recommended.

Specsavers has a product called SuperDrive lenses for varifocal wearers, while all of its glasses can be fitted with a clear ‘SuperClean Smart’ treatment, which is specially designed to help reduce reflections and dazzle caused by oncoming headlights and street lighting — helping you have a safer journey. 

Motorists suffering from glare at night should consult with their optician. 

6. Use low beams where possible to safeguard other drivers

Use your low-beam headlights instead of high beams when driving in well-lit areas or when approaching other vehicles as high beams can significantly increase glare.

7. Regularly adjust your headlights

Ensure that your headlights are correctly aimed, especially if you are often travelling with heavy loads, which can impact the height of your lights beam. 

Misaligned headlights not only contribute to blinding other drivers but will also reduce your own visibility.