The UK's unwritten driving rules revealed

From the Highway Code to Acts of Parliament, there’s plenty of scripture to dictate the dos and don’ts of driving in the UK.

But as any driver will know, there are conduct and etiquette conventions followed by many motorists that won’t be found in any rulebook or guide. The question is, could you get into trouble by following them?

To answer that, we not only dug out our copy of the Highway Code, but spoke to Neil Greig, director policy & research at road safety charity IAM Roadsmart.

From flashing your lights to clearing the inside lane, we’re here to breakdown, expose and discuss the unwritten rules of UK motoring.

Flashing your lights in thanks, or to let someone go

Let’s start with one of the most common unwritten rules out there. Flashing your headlights to thank another driver for waiting, or to let another driver out of a junction, is not just something that drivers do, but something that they’re expected to do by their fellow motorists.

But despite this practice being so widespread, the Highway Code strongly advises against it. Rule 110 states “only flash your headlights to let other road users know that you are there. Do not flash your headlights to convey any other message or intimidate other road users”. This is because flashing others, whether pedestrians or motorists, can send mixed signals, thus posing risks for everyone involved.

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The IAM’s Greig advises that a clear hand signal showing what you mean is usually less open to misinterpretation, and that you should always signal with your left hand because the right hand can sometimes be obscured by the windscreen pillar.

He also points out that particular care needs to be taken when accepting another driver's flash of invitation to pull into or out of a junction. "The invitee may have missed a cyclist, motorcyclist or a pedestrian in their blindspot. And taken slightly further the flash could just mean 'I am here, it’s up to you to make your own decision'"

Using your hazard lights for everything

Usage of hazard lights to say thank you to the car behind, to warn of suddenly slowing traffic, and to illuminate a car on tow – to name but three examples – is extremely common in the UK.

However Greig cautions against this usage. “While it is nice to say thank you, the over-use of hazard lights may lead to them not being recognised when a real situation develops.

"If part of your car is obscured, other drivers may also think you are indicating. Many new cars also have automatic hazard light flashing if they have braked very heavily, so be careful you aren’t missing a possible clue of trouble ahead.  Looking down to find your hazard flasher button, particularly in an unfamiliar vehicle, can be a distraction, so once again a clear wave with the left hand is best.”

Finally, Highway Code Rule 116 has something to say about using hazards on a car being towed: “You must not use hazard warning lights while driving or being towed unless you are on a motorway or unrestricted dual carriageway and you need to warn drivers behind you of a hazard or obstruction ahead.”

Parking generously in urban areas

Anyone who lives in a house without a driveway or in a block of flats will know the struggles of on-street parking. With cars slung on verges, kerbs and pathways, trying to maximise these parking spaces is something of a team effort.

While some understand the importance of being generous when it comes to street-side parking, others are more selfish and less spatially aware; therefore it’s not uncommon to find a car parked in such a way that means no one else can park either side of them, thus wasting precious kerbside space.

Parking on the pavement is not illegal except in London – and even there there are exceptions where narrow roads force this and have road markings explicitly allowing this. The Highway Code suggests drivers should not park on the pavement. Greig says "at IAM RoadSmart we can never condone driving onto the pavement, but if you do have to do it to let traffic flow then always leave at least 1.5m of space for wheelchairs and buggies to get through.”

Allow traffic to merge on motorways

Despite carrying 21% of all UK traffic, motorways only accounted for 6% of road fatalities in 2018 (the last year data is available for). While a recent campaign has seen gantries displaying the phrase “stay left unless overtaking”, some drivers take this a bit too literally around junctions.

All too often drivers sit planted in the inside lane, not moving over (when they can) to allow traffic to merge from a slip road. It’s courteous and often safest to move over briefly and allow traffic to merge.

Greig comments: “While the traffic already on the motorway does have right of way, a competent driver should anticipate the joining traffic and help its safe entry. Any behaviour that leads to stationary traffic on a motorway is potentially extremely dangerous. If there is no other traffic a lane change for a short period of time will help.”

But what if moving to the middle lane isn’t an option? In that case just slowing slightly and increasing your following gap will give joining traffic enough space to join easily. Most delays on our motorway system are the result of ‘incidents’ so anything we can do to work together to smooth the flow will help keep things moving safely. 

Give learner drivers more space

We all remember learning to drive: an instructor shouting in your ear, roundabouts with seemingly endless lanes, selfish drivers virtually hanging off your rear bumper – for most, it’s an unpleasant experience.

Therefore it’s a rule of the road to give learners more space than you would other drivers. Yes, they may be slow, yes, they may occasionally stall the car – but just remember what it was like when you were in their shoes; learning to drive is stressful enough without the car behind breathing down your neck.

The more experience a leaner driver has the safer they will be in the long run.  That may mean they are out and about in peak traffic but think of that as a good thing for their long-term development and don’t try to scare them off. Just learning on a quiet car park on a Sunday afternoon will not equip them for real-world driving and makes them a bigger risk to the rest of us.

Allow HGVs to overtake so they don’t lose momentum

Unlike most road cars, lorries rely heavily on momentum when scaling hills and inclines. That’s why you’ll often see HGVs side-by-side on dual carriageways, seemingly blocking the traffic. The reason is, if one of them is going even 1mph faster than the other, the faster one will want to overtake and creep past so not to lose momentum going up the hill; lorries may be powerful, but you try hauling around 40-tonne loads and you’ll understand.

While this may be an annoyance for the rest of us road users, lorry drivers appreciate it massively if you allow them room to perform an overtake when they need to – having to slam on the brakes due to selfish drivers, means lorries can struggle greatly in regaining their speed.

Allow cars out of junctions

This one will often depend on your mood, and whether you’re running late, but sometimes we all need to see the bigger picture. We’ve all been in a situation where we’ve been sat at a junction for what seems like an eternity waiting for a break in the traffic, or for someone to let us out.

So, next time you see a driver sat waiting for that break, be the one to give it to them and let them pull out. You’ll feel better for it, we promise. But how do you signal that? As already mentioned, flashing your headlights can be confusing.

Greig suggests “just slowing sufficiently to make the gap inviting and giving a clear hand signal with your left hand. If you have traffic behind you may need to communicate with them through your brake lights, but be aware though if you slow for no apparent reason they may overtake”.

If the driver behind is looking to overtake, allow them to when it’s safe

Sometimes we all enjoy a pleasant Sunday drive; we might even dip below the speed limit on the odd occasion to fully take in the scenery around us. And while that in itself is perfectly fine, we also have to accept that some people have places to be and people to see, and therefore don’t have time to dawdle.

So, if you’re the dawdler and can see there’s someone itching to get past you, slow down or move over when it’s safe and allow them past – they can get on with their day and you with yours, meaning everyone’s a winner. In fact, letting ‘faster’ traffic past is explicitly encouraged by Highway Code Rules  168 and 169.

The IAM’s Greig adds: “A good driver should be aware of what is going on behind them and if they are holding other traffic up, pull over when it is safe and let the other traffic past. They also advise to slow slightly to facilitate an overtake if necessary – HGV drivers take note.”  

Turn your music down

Whether it’s Stormzy, Mozart, Ariana Grande, or AC/DC, many of us enjoy listening to music in our cars, sometimes very loudly. And while that’s fine on the A34 where there’s nobody else to hear, it’s not so good when looking for a space in the supermarket car park, where everyone within half a mile can hear every note, chord and key change coming from your stereo.

There may be laws governing noise pollution, with fines applicable, but it’s unlikely that anyone will receive any real punishment for it. Greig goes further and says there is a safety aspect too: “Listening to loud music may affect your concentration, and your ability to hear outside noises such as a horn or an approaching emergency vehicle will be diminished. It’s also a distraction for other road users who often can’t help but look even if they don’t want to.”

Do not rubberneck

It’s tempting when there’s been a five-car pile-up or lorry fire on the other side of the road to slow down and take in as much of the carnage as possible. Shameful? Yes. Human nature? Yes.

It’s hard not to do it, but it can cause, especially on motorways and dual carriageways, hours of delays and unnecessary traffic – all because drivers are, to put it simply, nosey. In short, don’t rubberneck; not only does it cause massive delays, but it increases the chances of an accident on your side of the road.

Use the road space

What are the rules when two lanes become one? Some countries have this in law; in Germany, for example, they have what is called the Reissverschlusssystem, or the zipper system, whereby vehicles merge one-by-one. It makes a lot of sense and can reduce traffic delays. 

Greig advises: “Merge in turn is an effective way of controlling tailbacks, but don’t blast down the offside and then push in at the front of the queue. Use a sensible ordered approach where we then create enough space to share. The Highway Code also advocates this approach in rules 134 and part of rule 288 when speeds are low.  

The problem is that custom and practice seems to force everyone into one lane miles ahead of the restriction.  This just adds to delays. Authorities should use the zip sign much more often to give drivers a clear message and avoid road rage, but remember zip is the favoured method in the Highway Code.”

Warn others of speed traps

Often hidden and difficult to avoid, speed cameras are common in most parts of the country. Some drivers see it as their duty to warn others of especially mobile manned speed traps – often resulting in a quick flash to alert oncoming cars to slow down.

While this ‘all for one, one for all’ attitude might be appreciated in the driving community, it’s actually illegal. Deemed as “wilfully obstructing a constable in the execution of his/her duty”, warning other drivers could land you with a £1000 fine for breaking section 89 of the Police Act 1996. 

Greig adds: “A driver prosecuted for this is likely to receive a higher penalty than the errant motorist they warned. I doubt any argument that ‘you did it to slow traffic down for safety’ will be a runner as a defence.”

Don’t drive in other people’s blind spots

Deciphering another drivers’ blind spot is no easy task, but those that are regular motorway users find it’s a skill that develops over time.

When changing lanes on the motorway, drivers should always look over their shoulder – right or left – to check their blind spot. Unfortunately, a great many don’t do this, and therefore it’s not uncommon for drivers to move into another lane relying solely on mirrors, and causing an accident. It’s therefore sensible to avoid lingering in another drivers’ blind spot; this will usually be with the nose of your car just over-lapping the rear of theirs.

When towing, pull over and let others past occasionally

Many of the UK’s most beautiful campsites are in the depths of Cornwall, the heights of the Peak District, the hills of Summerset and the plains of the Norfolk coast. Therefore getting to them involves driving along winding roads and single-track lanes.

What does that mean? Miles and miles of queuing traffic across the country behind caravan-and boat-towing holidaymakers. So this entry of our unwritten rules guide states that if you’re towing a caravan (or trailer) on tight roads, make sure you pull over every now and again to allow the traffic behind you get on with their day. This behaviour is recommended by rule 169 of the Highway Code. 

Don’t loiter, get going

Finally, loitering. What many motorists can’t stand, is a dawdling, indecisive driver who brakes for every kink, and panics at every roundabout.

In short, don’t unnecessarily hang around – if the road is clear, keep rolling. We’re not encouraging anyone to break the speed limit, just to keep a moderate sense of haste when necessary. Lest we forget, thousands fail their driving test every year for ‘undue hesitation’.

If a driver is being over cautious be very wary.  They are either lost or under stress and either way not likely to be fully concentrating.  There are now more than one million drivers over the age of 80 and the number of older drivers are increasing every year.  There is a good chance that the driver in front of you may be elderly and just driving to their own abilities to keep their independence. It may be frustrating but give them some space in case the react unpredictably and only pass them if it is safe to do so.

Thanks to Neil Greig, Director of Policy and Research at IAM RoadSmart. He also serves on many key road safety committees including as a judge for the Prince Michael of Kent International Road Safety Awards, Scottish Government Road Safety Partnership Board, Transport Focus and Highways England Roaduser Panels and the DfT Motorycle Safety Strategy Group. 

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