Key takeaways
- On a motorway, quote the driver location sign or a marker post. National Highways asks for exactly this.
- Off the network, a three-word address or a dropped pin is usually the fastest accurate option.
- Under cover, none of them work. Concrete decks and underground car parks block the satellite signal.
- Where satellites fail, use the building: street address of the entrance, then level and bay number.
Every roadside problem has the same hidden dependency. The repair, the recovery, the replacement tyre — all of it waits on whether the person you called can actually find you. It is the part of a breakdown nobody rehearses, and it is the part that most often turns a forty-minute wait into a ninety-minute one.
There is no single answer, because the right method depends entirely on where you are standing. Three situations cover almost everything.
On a motorway: use the signs built for it
Quote the driver location sign. These are the blue signs at the nearside carrying the road number, a letter for the direction of travel and a distance in kilometres, and they exist for precisely this purpose. National Highways tells drivers to quote the numbers and letters on marker posts or driver location signs, and it is the single most useful thing you can say on the call.
If you cannot see one, marker posts run along the verge at roughly 100-metre intervals and carry the same information in smaller form. Between the two, the motorway network is one of the easiest places in the country to describe your position exactly, which is a small consolation for it also being the worst place to be stopped.
On ordinary roads: three words or a pin
A three-word address or a dropped map pin is normally fastest. On A-roads, country lanes and residential streets there are no location signs, and "just past the roundabout" describes several thousand places. what3words divides the world into three-metre squares each with a unique three-word label, and the company says a large majority of UK emergency services accept one.
A dropped pin in a maps app achieves much the same and has the advantage of already being installed on every phone. Either is dramatically better than a description. What matters is that you send a coordinate rather than a landmark.
| Where you are | Best method | Why |
|---|---|---|
| Motorway or major A-road | Driver location sign or marker post | Purpose-built, unambiguous, and what National Highways asks for. |
| Country lane or unnamed road | Three-word address or dropped pin | No signage and no useful landmarks. A coordinate is the only precise option. |
| Residential street | House number and postcode | Already precise. Add which side of the road and what the car looks like. |
| Multi-storey or underground car park | Entrance address, then level and bay | Satellite signal is blocked, so pins and three-word addresses are unreliable. |
| Large private site or retail park | Site name, postcode, then the unit or store you are outside | One postcode can cover a very large area with several entrances. |
Where none of it works: under cover
Under a concrete deck, satellite positioning degrades or fails entirely, and every tool above depends on it. This is the case people are least prepared for, because outdoors those tools are so reliable that nobody expects them to stop working. A pin dropped on level three of a car park can land on the roof, in the street outside, or a hundred metres away.
The answer is to stop describing geography and start describing the building:
- The street address of the entrance you came in through, not the shopping centre it sits beneath.
- Which entrance, if there is more than one, and the height clearance signed on the barrier.
- The level, and the bay number, both usually painted on the deck or on the pillar beside you.
- Anything fixed and named nearby: a lift core, a stairwell letter, a zone colour.
The same applies in underground residential parking, station car parks built under platforms, and delivery yards behind buildings. If you can see concrete above you, assume the coordinate is wrong and use the address.
What if you have no phone signal?
Try the call anyway, because an emergency call behaves differently from a normal one. When your own network has no coverage, a 999 or 112 call will attempt to connect through any other network that does, which means a call for help can get through in places where an ordinary call or a maps app will not.
Beyond that, the options narrow to the infrastructure around you:
- Motorway emergency telephones, where provided, are wired and do not depend on mobile coverage at all. They identify their own location to the operator.
- An eCall SOS button, fitted to many newer cars, connects and sends position automatically.
- Text messages sometimes send where calls fail, because they need far less signal and will keep retrying in the background.
- Walking to signal is a last resort, and never along a live carriageway. On a motorway, stay behind the barrier and use the phones.
Somewhere with no signal is also the one situation where writing down the marker post number before you move has an obvious payoff. If you do end up making a call from somewhere else, you can still say exactly where the car is.
Sending your location rather than describing it
If you can send a location instead of reading one out, do that as well, not instead. Every major messaging app can share a pin or a live location, and a coordinate that arrives on someone's screen removes the transcription errors that creep into a spoken postcode or a marker post number read out over passing traffic.
The things worth knowing before you rely on it:
- Live location expires. Most apps share it for a set period and then stop. If the wait runs long, it can lapse without either of you noticing.
- It costs battery. Continuous location sharing is one of the more expensive things a phone can do, and a dead phone is worse than an imprecise description.
- Send a static pin as well. A dropped pin stays put in the conversation and can be reopened later; a live share cannot.
- Say it out loud too. If the pin does not arrive, the spoken version is the fallback, which is why the marker post number still matters.
None of this replaces knowing where you are. It just means that once you know, getting that knowledge to someone else is no longer the weak link.
What else to have ready before you call
Location gets someone moving; the rest stops them arriving with the wrong thing. For a tyre specifically, four details decide whether the job can be completed on the first visit, and all four are readable from where you are standing.
- The registration. It identifies the vehicle and often the specification.
- The tyre size from the sidewall, the sequence like 205/55 R16 moulded into the rubber. Read it off rather than guessing from memory.
- Which wheel, and whether the tyre is flat, damaged on the sidewall, or simply losing pressure.
- What is in the boot: full-size spare, space-saver, sealant kit, or nothing. This decides whether it is a wheel change or a tyre job.
The locking wheel nut key is the fifth thing, and the one most often missing. If the car has locking nuts and you cannot find the key, say so on the call rather than discovering it when someone is knelt beside the wheel. There are options, but they change what needs to be brought.
Give us the location, the registration and the size off the sidewall, and we will tell you on the call whether the tyre can be repaired or needs replacing, and roughly when we can be there. Typically 30 to 60 minutes across London and the nearer Home Counties, longer further out.
If you are still on a live carriageway, safety comes first and this covers it. If you are under a concrete deck, the multi-storey guide goes further into why the signal fails there, and the emergency kit list covers what is worth carrying.
Frequently asked questions
A blue sign at the nearside of a motorway or major A-road showing the road number, a letter for direction of travel and a distance in kilometres. National Highways asks drivers to quote it when calling for help, because it identifies your position precisely.
It works wherever your phone can fix a satellite position, which is most outdoor locations. It becomes unreliable under concrete, so in a multi-storey or underground car park it can resolve to the wrong level or out into the street. Use the building address instead.
Work out the location first, because everything else depends on it. Outdoors, send a dropped pin or a three-word address. Under cover, give the street address of the car park entrance plus your level and bay number.
The registration, the tyre size moulded into the sidewall, which wheel is affected, and what is in the boot: full-size spare, space-saver, sealant kit or nothing. Mention locking wheel nuts and whether you have the key, as that changes the job.
No. Get behind the barrier first, as National Highways instructs, and read what you can see from there. If no sign is visible, the emergency telephone identifies its own location, and an eCall SOS button sends your position automatically.