Issued jointly by the Heavy Transport Association (HTA), the Construction Plant-hire Association (CPA) and the Road Haulage Association (RHA).

The HTA, CPA and RHA wish to bring to the attention of members and the wider industry - an increasing number of reported breaches of the 44-tonne (GTW) weight restriction on the M4 between Junctions 24 and 28, affecting both eastbound and westbound movements.

Recent incidents have involved abnormal-load movements, including mobile cranes, where operators have deviated from their notified routes, resulting in breaches of the applicable weight restriction and associated movement notification requirements.

We understand that enforcement activity is currently being undertaken in response to the presence of a structurally weak asset on this section of the motorway.

Operators and Transport Managers are therefore reminded of the following:

• Adhere strictly to notified routes: Where a movement has been notified and an agreed route established, drivers/operators must follow that route without deviation.
• Brief drivers appropriately: Drivers must understand the importance of following the notified route and the potential consequences of taking alternative roads or making unauthorised diversions.
• Escalate unexpected circumstances: Where road closures, incidents or other unforeseen circumstances make the notified route unavailable, operators should seek appropriate guidance before proceeding via an alternative route.

The presence of a structurally weak asset is not an administrative inconvenience; it represents a genuine infrastructure and public safety concern.  Weight restrictions must be respected, and operators must ensure that their movements are planned and executed accordingly.

The three associations would much prefer to see this issue addressed proactively through responsible operator behaviour and effective internal compliance procedures, rather than through enforcement action or, more seriously, an incident involving damage to critical infrastructure.

We ask all members to circulate this alert to their transport managers, planners and drivers, particularly those involved in abnormal-load and mobile crane movements in South Wales.

Compliance protects infrastructure, public safety and the reputation of our industry.