A3 Hindhead tunnel: advice for drivers

Guidance for drivers using the A3 Hindhead tunnel. Includes what happens when the tunnel closes for maintenance and planned closure dates.

The A3 Hindhead tunnel is the UK’s longest land tunnel. It takes the A3 under the Devil’s Punchbowl; an area of special scientific interest.

Traffic signs and signals help you navigate the tunnel safely and legally.

The national speed limit of 70mph applies and average speed cameras are in operation. If a temporary speed limit is in place, changes to the speed limit will be clearly indicated before you enter the tunnel and via the overhead traffic signs.


Highways England maintains the Hindhead tunnel on a regular basis to keep it safe to use. Work is carried out overnight when possible to reduce impact - generally 9pm to 6am.

Usually we close one tunnel at a time, keeping the second tunnel open in both directions under contraflow. For safety we impose a 40 mph speed limit through the contraflow and close the northbound Hazel Grove entry slip road.

We only close both tunnels if absolutely unavoidable.

If scheduled roadworks take place elsewhere on the A3 you will not usually be able to gain to access to the tunnel as the approach roads will be closed.


During full closures clearly signed diversions will be in place.

We know that long diversions are frustrating but ask you to resist taking another route, for example as suggested by your sat nav. We carefully plan diversion routes to ensure they can cope with the high traffic levels and agree them with local authorities and the emergency services. Using an alternative simply blocks local roads, preventing access to the emergency services – and larger vehicles may find themselves stuck on unsuitable country lanes.

Note that diversions may initially double back before taking you onwards.

Local access signs will be in place to indicate where a route is closed to all except local residents.

In an emergency

If you break down in the tunnel, turn on your hazard lights. If safe to do so:

  • exit your vehicle from the side furthest from traffic and ensure any passengers do the same
  • leave any animals in the vehicle
  • make your way to the nearest safety niche or passage – remember this may be behind you
  • use the emergency road side telephone – these connect you directly to the control centre who will let you know what to do and help keep you safe

Do not attempt even simple repairs. Do not attempt to cross the live carriageway

Standstill traffic

Standstill traffic is not allowed in the tunnel. This is for your safety and to allow access for emergency services. If traffic in the tunnel has come to a standstill you may be held outside the tunnel until the tunnel clears. Usually traffic is held for no more than 30 minutes and is allowed through the tunnel in batches until the queuing has cleared.

If traffic is at a standstill and you are stuck inside the tunnel, remain calm and await instructions either via the overhead traffic signs, public address system or direct instructions received from emergency services personnel.

Hindhead tunnel by bike

You cannot cycle through the Hindhead tunnel. Instead you must go via the Devil’s Punchbowl.

There are signs on the approaches to the tunnel before the last junction to let you know where to safely exit the A3.

Published 22 March 2017