Traffic across Bristol and surrounding areas has been heavily disrupted after a police-led incident forced the closure of the M5 motorway between Junction 18 (Avonmouth) and Junction 19 (Portbury).

The incident, described as "welfare-related," brought all traffic to a standstill during the peak morning hours, creating long tailbacks on the motorway and major diversion routes. Although the M5 has since reopened, congestion remains heavy as drivers navigate the rerouted traffic.

Traffic management systems initially reported severe congestion, with vehicles moving at average speeds as low as five mph. The closure prompted local authorities and National Highways to set up clearly marked diversion routes to keep traffic flowing, although these alternatives themselves quickly became congested as diverted vehicles poured onto city and suburban roads.

M5 Motorway Traffic: Major Diversion Routes Causing Spillover Congestion

Southbound Diversion - Hollow Circle Route

Drivers heading southbound on the M5 were directed to follow the Hollow Circle diversion route:

• Exit the M5 at J18 Avonmouth Spur Road.
• Take the slip road to Portway roundabout and the 2nd exit onto the A4 Portway.
• Continue south on the A4 through the city, noting that Bristol City Council confirmed the Clean Air Zone has been switched off for this closure.
• At Gurney Roundabout, take the 1st exit onto the A4174 South Bristol Link Road.
• Continue to Lime Kiln Roundabout, taking the 3rd exit onto the A38.
• Proceed to East Brent Roundabout and rejoin the M5 at J22.

While this diversion helped maintain movement, it led to heavy congestion along the A4 Portway and surrounding local roads, as motorists navigated through urban areas not designed for high traffic volumes.

Northbound Diversion - Solid Triangle Route

For northbound drivers, the Solid Triangle diversion directed traffic off the M5 at J21:

• Head east along the A370.
• Continue north on the A4, passing through Bristol (Clean Air Zone temporarily suspended).
• Rejoin the M5 at J18A.

This route, a key corridor connecting Weston-super-Mare and East Brent, became heavily congested, with backups extending beyond the usual commute zones.

M5 Motorway Traffic: Impact on Local Roads & Drivers

The unexpected rerouting has caused a ripple effect, with secondary roads also experiencing delays. As drivers avoided the blockade, traffic volumes surged on local roads not designed for motorway levels of traffic, leading to slow speeds and long waits.

Local authorities had confirmed that Clean Air Zone fines were switched off for the duration of the closure, giving relief to motorists forced through urban areas on diversion routes.

M5 Motorway Traffic: How Long Will Traffic Delays Last?

Transport officials are warning that delays could persist even after the motorway has fully cleared. When backed-up traffic begins to move again, recovery to normal speeds can take hours, especially on affected diversion routes where traffic remains heavy.

Drivers are advised to allow extra travel time, check real-time traffic updates before setting out, and consider alternative routes if possible until traffic conditions improve.