driver location signs

Helping us help you with driver location signs

Understanding motorway marker posts can help us get to you faster

If you break down or need to report an incident, it’s really important to know where you are.

You can give us your exact location instantly using the AA app. Alternatively, the driver location signs on motorways and A roads will help us or the emergency services find you.

You may have seen these small blue signs along the hard shoulder while driving on the motorway, but understanding them is another matter. Don’t worry, we’re here to explain each part of the sign for you.

What are driver location signs and where do you find them?

Driver location signs are small and blue. You’ll find them at the side of motorways positioned every 500 metres, and on some major A roads. You might hear them referred to as distance marker posts, UK highway signs or motorway sign posts. They were introduced in the early 2000s to give drivers additional information to the motorway marker posts - signs posted every 100 metres showing the directions to the nearest emergency phone. 

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How do you read a driver location sign (distance marker post)?

Driver location signs can give breakdown rescuers a quick idea of whereabouts you are. Providing them with the details written on the sign nearest to the incident will make it easier for help to get to you.

  • The top line shows which road you’re on
  • The letter on the second line – A or B – tells us the direction you’re travelling in
  • The bottom line tells us how far you are from a given location

Who should you call?

If you’ve broken down:

  • Report via the AA app. No need to give us directions, we'll come straight to your phone's location
  • Report online. Tell us about the problem and track your AA Patrol to your side
  • Call us. Call 03330 046 046 to get instant breakdown cover if you aren't already with us

Alternatively, you can:

  • Report a road traffic incident: call 999 or 112
  • Report debris in the road: call the Highways Agency Information Line on 0300 123 5000

Remember – if you’re driving alone, use a hands-free kit or pull over somewhere safe before calling

What do the different letters and numbers written on small blue motorway signs mean?

Below you can find a step-by-step guide on each part of UK motorway marker posts, so you know how to read them and understand your location.

Driver location sign


Line 1: the first line of the sign tells you what road you’re travelling on. If you are on the M42, it will say M42

Line 2: The second line of the sign will have an A or B, which will indicate which direction you’re travelling in.

  • What does A mean on the motorway?

    The letter 'A' refers to either the northbound side, the side on which the junction numbers increase, or Away from London

  • What does B mean on the motorway?

    The letter 'B' refers to either the southbound side, the side on which the junction numbers decrease, or Back to London

    On the M25, ‘A’ means clockwise and ‘B’ anticlockwise

  • You may see the letters J, K, L and M if you’re on a motorway slip road, depending on your location and the direction you’re travelling in.

Line 3: The third line on the location sign tells you how far you’ve travelled (in kilometres) from the start of the motorway you’re on. On the M25 for example, the distance is measured clockwise from the Dartford Crossing.

If you find yourself broken down on the motorway, remember to only give the nearest marker location information on your side of the motorway.

Use an emergency telephone if there’s one nearby and you can get to it safely. These are still the easiest and cheapest way to call for help.

Even if you can’t remember how to read a driver location sign, you can pass the information on to the relevant party who will know your location based on the numbers you provide.



How do you read a motorway marker post?

The first line of the blue motorway marker posts tells you the name of the road you’re travelling on (e.g. ‘M25').

The second line tells you the direction you’re travelling in (A or B), with A usually referring to north or clockwise, and B referring to south or counter-clockwise.

The third line tells you how far you’ve travelled in kilometres from the start of the motorway.

What are the numbered markers on the motorway?

These motorway signposts are driver location signs. If you break down on the motorway, you can call for help and relay the information on these signs, which will help breakdown rescuers find you quickly.

What are the blue markers on motorways?

Driver location signs have a blue background, these can be used in the event of a breakdown to help mechanics find you quickly and efficiently.

Published: 29 March 2016 | Updated: 19 May 2023 | Author: The AA