bridge status

Status icon M4 Prince of Wales Bridge - OPEN to all traffic.
Status icon M48 Severn Bridge - OPEN to all traffic.

Explanation of Status Changes

The status of either the M48 Severn Bridge or M4 Prince of Wales Bridge can be set as Open, Closed or Closed to High-Sided Vehicles with circumstances that trigger a full- or partial-closure including:

  • Adverse weather conditions, particularly high winds, low visibility and freezing conditions

  • Road traffic incidents where continued use of the bridge compromises safety

  • Other unforeseen situations


High Winds Filtering System

Between 1992 and 1996, 13 vehicles were blown over on the Severn bridges during high winds, resulting in more than 47 hours of closure. As a result a high winds protocol was introduced.

The High Winds Traffic Filtering System ensures the M48 Severn Bridge remains open and operationally safe for Category 1 (cars) and Category 2 (light commercial) vehicles for as long as possible.

We appreciate that the closure of the M48 Severn Bridge to all vehicles during high winds has an impact on road users by increasing journey times and, at times, congestion on the M4. We therefore constantly review methods to keep the bridge open to cars and small vans for longer, whilst ensuring safe operation during these periods.

In September 2007, the following High Winds Protocol was revised and remains in force:

  • 40 knots: Advance warning signs will be displayed. Bridge/s will remain open to all vehicles under 6’9″ (2.1m). The use of the M48 Severn Bridge by restricted vehicles (those over 2.1m in height and motorcycles) will not be permitted and an alternative route must be found. Filtering operates between 06:00 and 22:00. If conditions persist, the bridge will be closed to all traffic between 22:00 and 06:00.
    Highways England Traffic Officers will initially provide a visible presence to help reinforce the changes. Avon & Somerset and/or Gwent Police Forces will also support the operation.

  • 60 knots: Bridge/s closed to all traffic.

Drivers ignoring advice and attempting to use the bridge will be committing an offence and may face prosecution.

For further information, call the Highways England Information Line on 0300 123 5000 (open 24 hours a day, 365 days a year) or email

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