Think inside the box

Published on 20 August 2020

The yellow box junction is a familiar sight across the UK, keeping crossroads clear and traffic on the move. Not everyone understands the rules, though - so how well do you know this everyday patch of paint?

They go by all sorts of names: box junctions, yellow boxes, even criss-cross markings. And most of us recognise that, in a box junction, you're not allowed to stop. But there's more to it than that, and it's well worth understanding them: for the last 15 years, you could be fined for stopping in a yellow box in London, but since last year fines can be issued for stopping in box junctions anywhere in the UK.

There might soon be a lot of fines to hand out, because a surprising number of drivers have trouble with them. A few minutes searching the internet will turn up dozens of people who stopped in a box junction because they didn't know how to avoid it. In fact the RAC's research suggests that 80% of drivers claim to have "trouble" getting across a box junction without stopping, and - worryingly - almost 15% of drivers say they find it "difficult not to stop" at most of the box junctions they encounter.

The very simple explanation

  • Don't enter a yellow box junction unless there is enough space on the other side for your vehicle to fully clear it. If you're in moving traffic, don't just follow other vehicles in and assume they'll keep moving.
  • The only time you should stop inside a box junction is when you are turning right and you need to wait for a gap in oncoming traffic.
  • If you're not sure, stop before you enter the box.

For a more detailed explanation, we'll start at the beginning.

Unlocking the grid

Box junctions have their origin in a series of trials conducted in London during the 1960s. The aim was to stop traffic queueing across junctions, so that streams of vehicles crossing the jammed road had a clear path when the lights changed. Otherwise, crossing traffic would also start to queue, and in London's dense network of busy streets, one traffic jam quickly spawned another.

The trial used yellow road studs, which were placed in a box around the outside of the junction. Blue signs explained that waiting, loading, picking up and setting down were all banned within the area marked by the studs.

One sign from this trial clung on until a few years ago, at the junction of the A214 and A216 in Streatham, South London, but is now gone.

Watch out for the yellow studs: this early attempt at a box junction was short-lived. Click to enlarge
Watch out for the yellow studs: this early attempt at a box junction was short-lived. Click to enlarge

The new rule worked but the markings did not - the yellow studs just weren't obvious enough. So, when box junctions were introduced in 1967, they were given a much more noticeable indication: a grid of thick yellow lines, covering the whole area of the junction.

There's a whole list of other countries that use yellow boxes in the same way, but the British motorist might be surprised to learn that in some places - Australia, for example, and many EU countries - all junctions are treated as box junctions and no road markings are required.

Stacking boxes

Since those trials, the number of box junctions has grown enormously, but there are still only a limited number of places it's legal to place one:

  • At a junction between two or more roads
  • At a gyratory system or roundabout, covering only the part of the junction that is controlled by traffic lights
  • Along a narrow length of two-way road, where the carriageway is 4.5 metres or less at its narrowest point
  • Outside a fire, police or ambulance station

Those rules are from the Traffic Signs Regulations and General Directions (TSRGD) 2016, which is the legal document that sets out how road signs and markings should appear and how they must be used.

A yellow box on the B4102 Warwick Road in Solihull. Click to enlarge
A yellow box on the B4102 Warwick Road in Solihull. Click to enlarge

Interestingly, though, TSRGD 2016 relaxed a lot of the rules around box junctions. Previously they could only have so many sides and had to be a certain shape, or else they were unenforceable, but now they can be whatever shape is required "to cover all situations at junctions". Appeals based on strangely-shaped box junctions being unlawful might have worked before 2016, but won't now.

So exactly what is and isn't allowed?

Pandora's box

The Highway Code is pretty clear on these things. Look it up and it will tell you that:

"You MUST NOT enter the box until your exit road or lane is clear. However, you may enter the box and wait when you want to turn right, and are only stopped from doing so by oncoming traffic, or by other vehicles waiting to turn right."

The Highway Code, rule 174

The definition in law, though, is a bit more complex. In TSRGD, the wording is that "a person must not cause a vehicle to enter the box junction so that the vehicle has to stop within the box junction due to the presence of oncoming vehicles or other stationary vehicles beyond the box junction", with the exception of a driver who "stops the vehicle within the box junction for so long as the vehicle is prevented from completing the right turn by an oncoming vehicle or other vehicle which is stationary whilst waiting to complete a right turn".

Lots of cars stopped in the box on the A6042 Trinity Way, Salford - but all of them waiting to turn right. Click to enlarge
Lots of cars stopped in the box on the A6042 Trinity Way, Salford - but all of them waiting to turn right. Click to enlarge

If that doesn't answer all questions, let's test the law with some common problems.

"I was in moving traffic when I entered the box, but the traffic stopped, leaving me nowhere to go, so I had to stop in the box."

This doesn't wash. You must make sure your exit is clear before you enter the box, and if this happened to you, then you didn't do that. If you're in a stream of moving traffic, that is no guarantee you will make it all the way across, so you should wait until the vehicle in front has cleared the box and there is space for your vehicle on the far side before you enter it.

Of course, if you do enter the box in a stream of moving traffic - and thousands of people do every day - the traffic may well keep moving and you might get all the way over without stopping. In that case no rule has been broken, because you didn't stop. But you'd have left yourself with nowhere to go if the car in front suddenly hit the brakes.

"Traffic in my lane stopped, so I stopped in the box, but there was space in another lane for me to use if I needed to."

This one has been tested in case law multiple times and also doesn't wash. The legal test is whether, when you decided to take your vehicle into the box junction, your exit was clear. Not any exit - your intended exit. The fact that a different way out of the box was available, which you could have taken, means nothing if you didn't take it and instead you stopped in the box.

Interestingly, this defence was once accepted by an adjudicator reviewing an appeal against a box junction fine, in a case known as Sheikh v London Borough of Newham, a title that appears all over the internet in discussions about box junction fines - but that decision has been rejected as a precedent multiple times since, and is unlikely to be upheld by adjudicators looking at future appeals.

"I wasn't fully in the box when I stopped and I wasn't blocking anything."

This is also not allowed. The law states that all references to vehicles that stop in box junctions apply equally to "a vehicle which is stationary whilst part of it is within the box junction". If any part of your vehicle is within the outline of the yellow box when you stop, you have stopped in the box.

How can I be sure I'm in the clear?

Transport for London make £16m a year in fines from drivers who don't understand how to safely tackle a simple yellow box. With junctions nationwide now enforced in the same way, it's in every motorist's interests to know how box junctions work and how to approach them. It's not just about avoiding the fine - it's also about considerate driving that makes space for everyone's journey.

The answer, of course, is in those very simple rules at the start of the page.

Those very simple rules again

  • Don't enter a yellow box junction unless there is enough space on the other side for your vehicle to fully clear it. If you're in moving traffic, don't just follow other vehicles in and assume they'll keep moving.
  • The only time you should stop inside a box junction is when you are turning right and you need to wait for a gap in oncoming traffic.
  • If you're not sure, stop before you enter the box.


Bigmac 20 August 2020


Patrickov 21 August 2020

Hong Kong employs an almost identical system of yellow boxes and drivers are far more obedient, except in serious jams. We find it extremely easy to follow, compunded by the fact that right turn pockets are being systematically removed across the territory, in favour of widened junction entrance with dedicated lanes and phased traffic lights.

What I really don't understand is the "keep clear" marking seen both in Britain and Hong Kong. At least in Hong Kong such markings used to be denoted by yellow boxes. Why introduce another marking to confuse drivers?

Nice to meet a fellow Hong Konger on here; I'm presuming that the Keep Clear marking was introduced for exits from private property (mostly schools and private car park areas from my experience) to public roads? Or possibly as a less visually intrusive alternative to the yellow box? Either way I agree with your view that the Keep Clear marking is redundant considering the yellow box exists.

Keep Clear and White Cross-Hatched Boxes are advisories, and I don't think they have any legal standing.

Koppie 21 August 2020

As an outsider looking in I am still wondering how much those boxes(especially the larger ones) are hampering the throughput if everybody were following the rules.

By automating fines you as always take away any digression, and you don’t catch the people who regular does block crossings, but know where the cameras are.

Paul 21 August 2020

One issue with these is that if you attempt to be a law-abiding citizen you will often find yourself going nowhere as other less scrupulous drivers simply bypass you and occupy the space in the box junction ahead of you.

Another thought I have also had - what defines "stop" when related to these junctions? If, for example, I realise I am not going to clear the junction so slow to a crawl, barely - but still - moving until I am able to clear the junction, presumably no offence is committed?

Speed has nothing to do with it; you need a gap on the far side, in your intended lane, big enough for all of you to fit in when you enter the junction.

Fraser Mitchell 21 August 2020

These Yellow Box Junctions just have to be the most lucrative of all traffic features to the councils that are now empowered to enforce them as today's traffic is vastly greater than the 60s when these things were first visited upon the hapless UK motorist. Also note that it is civil, not criminal enforcement by councils and is only authorised so far in London, the rest of the UK is a police matter and is not carried out. The police sensibly leave to to motorist's sense of politeness rather than whalloping all and sundry with penalties for this very minor offence..

Enforcement was, of course, almost nil until the offence of stopping within a YBJ was handed over to London councils, (and Transport for London) in recent times. Enforcement by CCTV is the only method used to enforce and is very cheap to install and the fines money accrues to the councils in its entirety, giving councils a huge revenue stream to waste on councillor's pet schemes.

The use of CCTV, not available in the 60s means the law is now well out-of-date. At the moment the offence is absolute, the council do not have to prove any actual obstruction was caused, they just have to show the vehicle was there; yet CCTV is easily able to show the difference. Bus lanes are similar; all the council has to show is the vehicle was in the bus lane, not that it had obstructed a bus.

I post advice on on the council PCNs section. Readers here should jot that site address down for when they too get a Penalty Charge Notice. They might be surprised at the amount of illegality there is in councils when enforcing parking and other motoring restrictions. The average motorist knows very little about the law in this area, and this is ruthlessly exploited by councils.

That is a reasonable treatment of the offence, that it is absolute. If it required that an obstruction be caused one could instead be charged with any of the offences for causing an obstruction or for driving without due care. Issuing PCNs in order to keep the bus lanes and box junctions clear at all times to allow them to work properly is as much a part of driver education as are speeding fines.

Agreed @cjeam - relying on motorist politeness is a laughable idea. We need to keep the city moving so rules are there to be obeyed and enforced. It is irrelevant whether in an individual case another road user was blocked - it is the principle of the law that needs to be upheld, or it will be even more confusing for the dithering or ill-informed driver. Now, whether councils and other agencies are unscrupulous or illicit on how they raise income from fines is another matter - perhaps proper local taxation to fund public services, and the fines income being diverted to driver education and road safety schemes, would remove any temptation to view box junction and banned turn offences as a nice little earner?

Of course the rule should be absolute; If a driver can't follow simple rules they deserve to be fined. Bus lanes are exactly that, lanes for buses. Not lanes for stupid drivers to use just because they feel like it. Whether or not they obstruct a bus is irrelevant.

It makes perfect sense to me to use a lane that isn't otherwise being used, there's nothing there to indicate a driver is "stupid" at all. In certain areas where there is a constant stream of buses it's understandable to have them in place, but in areas where there are perhaps one bus an hour at certain times, or even none at all (they do exist) then their use should be allowed.

Anyone who thinks those things are placed just to allow the flow of buses unheeded is a fool. In most cases its just another cash cow that increases, rather than reduces, traffic congestion by taking away much needed, perfectly useable, road space.

Without the fines that go with them, many bus lanes and box junctions in the capital simply wouldn't exist.

Here in Blackpool we have one that barely a bus length. It's purpose seems to be to ensure buses don't need to make a left turn. Fine, but why not just take away the corner completely instead of the considerably higher expense of creating a relatively pointless bus lane?

Then surely the solution is still not to use them, if it deprives the authorities of your well-earned cash, rather than use them anyway and erroneously claim ignorance or illegality?

It's true that bus lanes spend most of their time during active hours empty, but the law still needs to be obeyed, however ridiculous.

I've never seen it happen, but I imagine that very occasionally, buses might not be able to proceed because the lane is blocked if people ignored it. However, a rule as per box junctions; don't enter the bus lane unless you would be able to move out to let a bus to pass, would be a better idea.

Is there any evidence that the money raised from fining drivers who illegally use bus lanes is the reason they are installed, or is that just a big "I reckon"? Installing a bus lane in the hope of raking in money from fines would be a very uncertain and low-return stream of income compared to the cost of the installation and the quantifiable economic and social benefits of buses running reliably to time. I would be astonished if the money raised provided a significant income stream for any public body.

To me it seems self-evident that bus lanes and box junctions in London would exist with or without fines being collected. These things are a perfect fit with the transport policies of administrations of every political colour at both the London-wide and borough level over the last forty years. If it was political, if there was some grand money-grabbing conspiracy at the heart of bus lanes and box junctions, you'd expect someone somewhere to use that as part of their election campaign. But they never have.

"Is there any evidence that the money raised from fining drivers who illegally use bus lanes is the reason they are installed,"
Well, yes, but indirectly. The Mayor of Liverpool who seems more human than the usual apparachiks, decided to have a review of the benefits/disbenefits of bus lanes in the city. The final report conclusions were that almost all the bus lanes gave no overall benefit apart from four. Objections came from the city officials who pointed out that the fines revenue would be lost. This was over £1 million a year. The mayor persisted and only four bus lanes were kept, and buses continue to run satisfactorily to this day.
One argument against bus lanes was "why should bus companies be favoured over other companies that need to use the same roads ?"
The question that will, I suppose, never be answered, is - would there be so many bus lanes if all enforcement income accrued to the government, not the council ?

JGH 21 August 2020

'Keep Clear' are advisory, not legal, they are there as an additional indication there is a side entrance that traffic needs access to. You cannot be prosecuted for blocking a Keep Clear, but you are still open to being prosecuted for obstructing the highway, driving without due care and attention, etc., and may loose marks on your driving test.

Sounds right to me! Keep clear markings are advisory, but like many advisory signs and markings, you can still be pulled up for not observing them, because failure to observe them can be considered poor driving. 

Floyd 22 August 2020

I remember many years ago in London I was queueing up to get through a T junction. There was no way on earth you could avoid waiting in the box because if you stopped back from it as should be done, the traffic in front was so slow to clear, that the lights would then change and one (maybe two) vehicles would then enter from the left-hand side road. When the lights for me (to go straight ahead) changed to green, those two vehicles were still in the box. It would have been impossible to avoid in a small car, let alone anything longer. Luckily there wasn't a camera (or it wasn't working), as they would have made a fortune on fines that day.

Still not really an excuse, though. If you have to wait your turn, then wait. Otherwise you're blocking turning traffic from coming out.

I'm convinced that signals would be timed differently if people navigated these junctions properly in the first place.

Well, that only works if EVERYONE obeys the rules. The side traffic kept coming, so I'd still be there now if I didn't enter the junction (and probably would have also been harrased by the people behind me). Whether there'd been an accident further up the road I don't know, but if not and it was a 'normal' situation then the signals needed to stay on red longer to allow traffic to clear the box. - But when you consider that there are people who won't even leave a gap on a level crossing and are quite happy to straddle the railway lines, what hope have us good drivers got anyway really?!

Exactly the same happened to me in London, traffic was moving OK in the left lane when some idiot cut in from the right (usual occurrence in London) hence stopping all the traffic, the lights changed leaving me stranded with a third of my car stuck in the yellow box. Just another tax on the motorist and another good reason not to visit London.

Gareth 22 August 2020

I tend to find that people don't understand that turning traffic can wait in the box, so long as their intended exit is clear. There was one intersection I had to do this regularly and the honking and dirty looks I'd frequently get from other motorists. Stupid, because the road I was entering from had only a single approach lane. If that was the rule, I'd have to sit at the stop line and block all the through traffic behind me. I doubt they'd appreciate that either.

YNM 25 August 2020

I'm wondering if there could be cut-outs in the marking just to mark that, when the traffic light allows you to start a turn but still being blocked by opposite traffic, you can stop within the box area.

Matthew Sparks 25 August 2020

I'm in full support of the use of box junctions, I just wish many other drivers are. So many times I've been beeped at for not proceeding forward on a green, because the road ahead is still full. What's even worse is when you wait, then the priority changes for traffic. They barge in and you're back in the same position - albeit with even more angry traffic behind you.

Phil 26 August 2020

You missed Railway and Tramway level crossings out of the list of place yellow box marking may appear.

That said as regards railway level crossings the use of a box junction is governed by legislation relating to level crossings, if yellow box markings are required then it will be specified in the individual Level crossing order made by the Secretary of State for that crossing. Hence why some have them and some don’t

There's a tramway level crossing in Sheffield at the inner ring road near Shalesmoor roundabout. Although it's clearly marked with a box junction you'll often someone's back end jutting into it, meaning the tram has to inch past or hoot them to get out of the way.

When Sheffield city council decided to narrow all the approaches to the roundabout (a genius scheme that they later made a swift u-turn on when they realised it was doing more harm than good), the three lanes of stacking space just beyond the level crossing were reduced to two, with no decrease in traffic. As a result, anywhere near peak times, there were more vehicles blocking the tramway and delaying citybound trams for 2-3 minutes at a time.

Chapman Baxter 2 September 2020

If you enter a box and suddenly realise there is not quite enough room to exit, is it legal to move across the box at 1 mph, for say 10 seconds, by which time space has become available to exit the box?

Completely legal, in fact on the webforum '' that is our advice for the future to people who've been whalloped. The contravention also only applies if you stop in the box due to stationary vehicles; stopping if a pedestrian runs across is not a contravention.

No. Movement and speed are irrelevant. There needs to be space available on the far side, in your intended lane, when you enter.

Sorry, you're not correct. The contravention occurs when the vehicle enters the box and then has to stop due to the presence of stationary vehicles. The Highway Code, (where I suspect you got this from), tells you not to enter the box unless there is space to accept your car on the other side. Yes, this almost guarantees you won't stop in the box, but if rigidly adhered to in London would bring them to a grinding halt. So, yes, best to only enter when there is space to allow you to exit, but rapidly moving traffic really doesn't allow of this assessment being made; things are just happening too quickly, We do see a lot of videos on "" where people charge into the box in a gung-ho manner following vehicles in front, which stop leaving them with no exit and they get a ticket. So one must be cautious as virtually every box in London is covered by CCTV

So if i enter a box just as another vehicle at the other end in the same lane is exiting, and i continue at the same speed, not even slowing, never mind stopping, and leave the box into a space that has now been vacated, this is an offence, because technically the vehicle leaving the box at the other end hadn't quite exited the box when i entered it?

That doesn't seeem right to me. Cars just travelling at normal speed over a box of junction of say 20 metres length, would be continually having to slam their brakes on to obey the law.

No, the offence is stopping in the box. If you haven’t stopped in the box, no offence has been committed. But if you enter the box when there isn’t yet space at the other side for you to exit the box, you cannot be certain that you will be able to cross it without stopping. 

Phil 5 September 2020

There is a box junction near me at a set of traffic lights on a two lane dual carriageway. There is a signal controlled roundabout 40 or 50 yards further on. During the rush hour it is not uncommon for traffic to queue back from the roundabout past the box junction. More than once I have entered the box with my intended exit lane clear, but a car in the next lane, finding his exit blocked, cuts in front of me and blocks my exit, forcing me to stop in the box.

As I understand it I have done nothing wrong, my exit was clear when I entered the box. Proving it is another matter though. A similar situation could occur if you enter the box to turn right, with your exit clear, but traffic coming in the opposite direction, turning left into your exit road, blocks it before you have aa opportunity to move.

No, you're in the wrong and could theoretically be fined.

The offence is stopping within a yellow box junction due to the presence of stationary vehicles, unless turning right. The circumstances why the other vehicles are blocking you is irrelevant.

That may seem unfair but to be honest judicious use of mirrors usually tells you if some muppet is approaching at speed in the adjacent lane and is going to cut in front of you. Many motorists seem to think that "fairness" then allows them to break the law or lower their standard of driving. They may well get away with it most of the time, but if they are caught they should accept that redressing the balance is not a term you will find in the highway code.

Entering then stopping in the box to turn right is perfectly OK. You stop until there is a gap in the traffic in the opposite direction, then make the turn. This traffic movement is in the legislation.
Yellow box junctions in England are only enforced in London at the moment but the government are proposing to roll-out the powers in the Transport Management Act 2004 to councils in England. London YBJs are enforced under London-specific legislation.
The only evidence of the alleged contravention is the video taken at the time, so if you want to fight a YBJ PCN, you must view the video. We see a lot of threads on YBJ PCNs for London, and most are not really amenable to appeals as too often they show the motorist rushing into the box without any hesitation at all.

Thomas 8 September 2020

The reality is in all too many cases, if you don't risk blocking the box you'll be waiting for the rest of the rush hour. The issue occurs when the lights you're at and the next set of lights are mis-synchronised, so that space is only created at your exit when your light is red and other traffic promptly fills that space.

Neil 6 October 2020

Although I am fully aware of the box junction rules, I got done in London 2 years ago, which was very unlucky as I was waiting at lights wanting to turn left, as did the two vehicles in front of me. When the lights turned green we set off and almost immediately around the corner was a pedestrian crossing on red which I was unable to see when I started moving. The two cars in front of me had just about cleared the box junction but I was trapped on the corner of it. I knew I'd get a ticket and sure enough a week later one arrived in the post.

Rich 10 October 2020

So if I'm turning right and my exit is clear, but by the time oncoming traffic has ceased my exit is blocked by oncoming left turners, I'm not breaking the rules?

Chris 11 October 2020

Not breaking the rules.

You are still blocked by oncoming traffic. The legislation specifically says "so long" as this is the case. It is clear oncoming traffic turning left would be a part of this as long as they block you exiting from the YBJ.

Stephen Ogley 29 January 2022

This is going to seriously affect the throughput of traffic at rush hour on the A6 in Stockport where vehicles routinely follow moving traffic across a box junction instead of waiting for the exit to be clear and where consecutive traffic lights frequently cause backups into the yellow box.

Richard 17 May 2022

I was surprised to see yellow box junctions in Toronto.

Jonathan Cleveleys 4 August 2022

I have seen barely any in Doncaster, having to travel there for work (I live in nearby Hatfield) but have heard of a lot of drivers misusing these boxes elsewhere and ending up getting a hefty fine.

Add new comment

About text formats

Restricted HTML

  • Allowed HTML tags: <a href hreflang> <em> <strong> <cite> <blockquote cite> <code> <ul type> <ol start type> <li> <dl> <dt> <dd> <h2 id> <h3 id> <h4 id> <h5 id> <h6 id>
  • Lines and paragraphs break automatically.
  • Web page addresses and email addresses turn into links automatically.
All comments posted to are moderated before appearing online. Your comment won't be visible immediately.


Picture credits

What's new

Sorry, wrong number

Road numbering is a system with clear rules. What happens when the people responsible for numbering roads don't follow them?

We need to talk about Wisley

National Highways are spending a third of a billion pounds rebuilding one of the most congested junctions on the M25. Is it money well spent?

Oxford's Ground Zero

Oxford's Zero Emission Zone is just a trial, but transport policy in Oxford has become the catalyst for pitched battles and drawn in protestors from across the UK. What's happening to this genteel university town?

Share this page

Have you seen...

Mixed Signals

During the 1960s the UK developed some of the most sophisticated - and strange - electronic variable message signs anywhere in the world. How? And, just as importantly... why?

About this page


Last updated