Broken Down on the M27 or A3(M)? What To Do First

The M27 is one of Hampshire’s main motorway routes, running between Cadnam and Cosham and linking Portsmouth and Southampton. National Highways describes it as a key route for freight, holidaymakers and commuters, especially traffic linked to the ports and connections to the M3 and A3. The A3/A3(M) corridor is also a key north–south route, linking Portsmouth towards Guildford and beyond. That means when something goes wrong on either road, the situation can escalate very quickly because of speed, traffic volume and limited safe stopping places.

The most important thing to understand is that a motorway breakdown is not a mechanical problem first. It is a safety problem first. The reason official guidance puts so much emphasis on “go left, get safe, get help” is because being stranded close to moving traffic creates a much bigger risk than the original fault in the vehicle. If you remember nothing else from this page, remember that.

1. If the Vehicle Is Still Moving, Do Not Wait for It to Get Worse

One of the easiest mistakes to make is carrying on “just a bit further” when the vehicle has already started to show signs of trouble. National Highways says that if your vehicle develops a problem — or if you see a red or amber dashboard warning light — you should leave the carriageway at the next exit or pull into a service area if possible. That matters because the safest place to stop on a motorway is a service area, and other places of relative safety include emergency areas and hard shoulders rather than live traffic lanes.

• If the vehicle is still driveable, aim for the next exit or a service area.
• If you cannot make that safely, move as far left as possible.
• Do not stop in a live lane unless it is absolutely unavoidable.

This is especially important on busy Hampshire routes. On the M27, traffic is often dense because it connects the Southampton and Portsmouth side of the Solent corridor. On the A3(M), traffic can still be travelling fast even when the road “feels quieter,” and people often underestimate how hard it is for other drivers to react to a stopped vehicle ahead.

2. Know What Counts as a Safe Place to Stop

The Highway Code uses the phrase place of relative safety. That means somewhere you, your passengers and the vehicle are less likely to be hit by moving traffic. On motorways and other high-speed roads, the safest place is a service area. If you cannot reach one, the Highway Code says other places of relative safety include lay-bys, emergency areas and hard shoulders.

That hierarchy matters:

• Best option: service area
• Next best: emergency area
• Then: lay-by or hard shoulder where present
• Worst case: stranded in a live lane

If you can reach a proper stopping place, do it early. The closer you get to a real stopping area, the more control you have over what happens next.

3. Follow the “Go Left” Rule

If you cannot leave the motorway and the vehicle is failing, the next instruction is simple: go left. Both the Highway Code and National Highways say that if you cannot exit, you should move into the left lane and then pull into an emergency area or onto the hard shoulder if you can.

Once you stop:

• Stop as far to the left as possible.
• Leave space to exit the vehicle on the side furthest from traffic.
• Turn the wheels to the left.
• Switch on hazard warning lights.
• If visibility is poor or it is dark, use sidelights as well.
• If possible, stop just beyond an emergency telephone.

The detail about the wheels being turned left is easy to miss, but it matters. If another vehicle hits yours, it can help reduce the chance of your car being pushed further into live traffic.

4. Understand Emergency Areas, Hard Shoulders and Smart Motorway Sections

This is where many drivers panic because they are not quite sure what they are looking at.

The Highway Code says emergency areas are located on motorways with no hard shoulder, or where the hard shoulder can be used as an extra lane. They are marked by blue signs with an orange SOS telephone symbol and may have orange surfacing. National Highways says they are specifically there to provide a safer place to stop in an emergency when there is no permanent hard shoulder available.

The M27 corridor includes smart motorway-related infrastructure and motorway management features, so it is worth understanding this before you need it.

• An emergency area is for emergency stopping only.
• A hard shoulder, where present, must only be used in an emergency unless signs or officers direct otherwise.
• A red X means the lane is closed. The Highway Code says you must not drive in a closed lane.

That last point matters on the M27 in particular. If a lane has a red X above it, there may be a stopped vehicle, emergency workers, or another hazard ahead. Driving in that lane is not just risky, it goes directly against the Highway Code.

5. Once Stopped, Get Safe Properly

Stopping is only half the job. The next step is get safe.

If it is safe and possible to exit:

• Exit via the side furthest from the traffic.
• Make sure passengers do the same.
• If you have high-visibility clothing within easy reach, put it on.
• Get behind the safety barrier if there is one.
• Keep children under control and away from the carriageway.
• Stay alert for debris or vehicles coming towards you.

Official guidance is very clear about what not to do:

• Do not stand where your vehicle could be pushed into you.
• Do not go back to the vehicle even if it is raining, cold or dark.
• Do not attempt repairs.
• Do not place a warning triangle on the carriageway.

The no-warning-triangle rule catches people out. The Highway Code allows warning triangles on ordinary roads in some cases, but says they must never be used on motorways.

6. If It Is Not Safe to Get Out, Stay In the Vehicle

This is one of the most important points on the whole page.

If you cannot get the vehicle to the left lane or another safer stopping place, and you cannot exit safely, the Highway Code and National Highways say you should:

• Stay in the vehicle
• Keep your seat belt on
• Keep hazard lights on
• Call 999 immediately and ask for the police
• Or use the SOS/eCall button if your vehicle has one and ask for the police

This advice feels counter-intuitive to some drivers, but it exists for a reason. If you cannot get out without stepping into moving traffic, or you are trapped in a live lane with no safe route behind a barrier, staying belted in while help closes lanes and reaches you is the safer option.

7. Get Help — and Give Your Location Properly

Once you are as safe as you can be, the final step is get help.

National Highways says that if you are in an emergency area, lay-by or on the hard shoulder, you should use the free emergency telephone if there is one, or call National Highways on 0300 123 5000 for advice and assistance, then contact a breakdown recovery service.

If you are on the M27 or A3(M), your exact location matters a lot because junctions, slip roads and route direction make a big difference to how quickly help can reach you. National Highways recommends using marker posts, driver location signs, a mapping app, or your vehicle’s eCall system to communicate your location.

• Tell them the road: M27 or A3(M)
• Say which direction you are travelling
• Give the nearest junction, if you know it
• Use the numbers/letters from a marker post or driver location sign if possible
• Tell them if you are in an emergency area, on the hard shoulder or stuck in a live lane
• Tell them if anyone in the vehicle is vulnerable, elderly, disabled, or a child

That last point is important because National Highways specifically advises motorists to mention if they are vulnerable, older, disabled or travelling alone.

8. What To Do Specifically on the M27

The M27 is not just “a motorway in Hampshire.” It is one of the county’s most important routes. National Highways describes it as the south-coast route between Cadnam and Cosham, connecting Portsmouth and Southampton along the Solent, and says it is heavily used by freight traffic, holidaymakers and commuters.

In real terms, that means a breakdown on the M27 can affect:

• drivers heading into or out of Southampton
• drivers crossing Fareham and the central south coast corridor
• people heading towards Havant, Waterlooville and Portsmouth
• port traffic, delivery vans, contractors and commuters

If you manage to get off the M27 safely, the most useful internal pages are usually:

• Southampton Recovery
• Fareham Recovery
• Havant Recovery
• Waterlooville Recovery
• Portsmouth Recovery

9. What To Do Specifically on the A3(M)

The A3(M) feels different from the M27 but should be treated with the same seriousness. National Highways’ south coast route strategy describes the A3/A3(M) corridor as the main north–south access route from Portsmouth towards Guildford and beyond.

That matters because drivers sometimes underestimate it. The A3(M) can feel more open than the M27, but traffic still moves quickly and safe stopping places are still limited. If your car develops a fault there, the same rules apply: get left, get safe, and get help.

If you come off the A3(M) safely, your best internal links are usually:

• Havant Recovery
• Waterlooville Recovery
• Petersfield Recovery
• Portsmouth Recovery

10. What Not To Do on the M27 or A3(M)

If you remember the official “do” list, also remember the “don’t” list.

• Do not keep driving a clearly unsafe vehicle just because you want to get a bit further.
• Do not stop in a live lane unless you absolutely cannot avoid it.
• Do not drive in a lane marked with a red X.
• Do not use a warning triangle on the motorway.
• Do not stand beside the vehicle near fast traffic.
• Do not go back to the vehicle if you have already reached a safer place behind a barrier.
• Do not attempt a roadside repair on the carriageway or verge edge.

These are the actions that tend to turn a breakdown into something much worse.

11. After the Immediate Danger Has Passed

Once you are off the motorway or in a genuinely safer place, you can think about the actual fault. Some motorway breakdowns turn out to be battery-related or minor. Others are overheating, tyre, starter, engine, or electrical problems.

If the issue is more of a non-start after you’ve reached home or another safe location, these pages may help:

• Jump Start Assistance
• Battery Replacement
• Vehicle Transport
• Contact AtWheel

But if the vehicle is still not safe to drive, or you simply want it moved to a garage without messing around, the best starting point remains: Breakdown Recovery Hampshire

12. Helpful Official Links

If you want the official guidance pages behind this article, use these:

• The Highway Code – breakdowns and incidents
• The Highway Code – motorway rules
• National Highways – driving on motorways
• National Highways – emergency areas explained
• National Highways – M27 route information

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