What the Highway Code Says About Driving Into Sun Glare (and the £100 Fine to Avoid)
Low summer sun is one of the most underrated hazards on British roads, and the Highway Code is clearer about it than most drivers realise. If you are dazzled by bright sunlight and carry on regardless, you are not just taking a risk, you could be committing an offence that carries a £100 fixed penalty and three points, and a great deal more if it ends up in court. With the sun sitting low at the start and end of long June days, it is worth knowing exactly what the rules expect of you.
Here is what the Highway Code says, the penalties that can follow, the sunglasses and windscreen rules that catch people out, and the simple steps that keep glare from turning into a collision or a fine.
What Rule 237 actually says
Rule 237 of the Highway Code, part of the section covering driving in adverse weather, states that if you are dazzled by bright sunlight you should slow down and, if necessary, stop. It is short and unambiguous. The Code treats blinding sun in the same bracket as fog, heavy rain and ice, because the effect is the same: a moment when you cannot properly see the road ahead. The expectation is that you adjust your driving to the conditions rather than press on and hope.
The risk is at its worst in the early morning and late evening, when the sun sits low on the horizon and shines straight down the road into drivers’ eyes. A dirty or smeared windscreen makes it far worse, scattering the light and turning a bright patch into a wall of white. Pollen, dust and the greasy film that builds up on the inside of the glass all add to the problem in summer, which is why a screen that looks fine at midday can leave you blinded at sunrise.
The fines and penalties explained
The Highway Code itself uses the word “should”, which makes Rule 237 advisory rather than a direct offence on its own. The catch is what happens if you ignore it. A driver who keeps going while unable to see properly, and drives in a way that falls below the standard of a careful and competent motorist, can be charged with driving without due care and attention. That carries a fixed penalty of £100 and three points on your licence.
If you contest the fixed penalty and the case goes to court, the stakes rise sharply. Careless driving can attract between three and nine penalty points, a discretionary disqualification, and an unlimited fine. Should being dazzled by the sun contribute to a collision, the consequences can be far more serious still. The point the law is making is straightforward: the sun being in your eyes is not treated as an excuse, because the Code told you to slow down or stop, and choosing to carry on is a decision you are responsible for.
There is an insurance dimension too. If you drive on while genuinely unable to see and then have an accident, your insurer can treat the claim as your fault, and in some cases your conduct could affect whether a claim is paid at all. That is a similar principle to the one we set out when looking at how dazzling headlights have pushed many drivers to cut back on night driving: being unable to see clearly is a reason to ease off, not to keep going.
Sunglasses, windscreens and the rules drivers miss
A good pair of sunglasses is one of the best defences against glare, but the wrong pair can land you in trouble. Sunglasses are graded from category 0 to category 4 by how much light they let through. Category 4 lenses, the very darkest, transmit too little light to be safe for driving and are not legal to wear at the wheel during the day. They are designed for high mountains and glaciers, not motorways. Categories 2 and 3 are the usual choice for driving in bright conditions, and it is worth checking the label or the inside of the arm to see which grade you own before relying on them on the road.
The windscreen carries its own legal weight. Drivers must have a full view of the road and traffic ahead, and a screen obscured by dirt, smears or a spreading crack can leave you facing a fine and points in its own right, separate from any glare offence. A chip or crack in the driver’s line of sight can also fail an MOT. In practice the two issues combine in summer: a marked or grubby windscreen and a low sun are a far more dangerous pairing than either on its own, and both are within the driver’s control.
How to cut the glare and stay safe this summer
The most effective steps cost very little. Keep a pair of category 2 or 3 sunglasses in the car so you are never caught without them, and clean the windscreen inside as well as out, since the interior film is what causes most of the scatter. Top up the washer fluid and replace worn wiper blades before they start smearing rather than clearing, because a single swipe through summer pollen on a tired blade can blind you at exactly the wrong moment. Keeping the glass clear is the same basic discipline that pays off across the season, alongside the tyre and breakdown checks we flagged when record May heat raised the risk of summer blowouts.
On the road, use the sun visor, drop your speed when the light is in your eyes, and increase the gap to the vehicle in front so you have time to react to anything you cannot see clearly. Be especially careful at junctions, crossings and on rural roads at dawn and dusk, where a pedestrian, cyclist or stopped vehicle can be hidden in the glare. If you are planning an early start or an evening drive, factor in a little extra time so you are not tempted to push on through conditions that call for slowing down.
Above all, take Rule 237 at face value. If the sun leaves you unable to see the road, slow down, and if you still cannot see, find a safe place to stop until the moment passes. It feels like a small inconvenience, but it is exactly what the Highway Code asks, it keeps you on the right side of the law, and on a bright summer morning it can be the difference between a safe journey and a serious one.
Sources: