When transporting dangerous goods by road, one of the most important considerations that drivers must factor into their journey planning is tunnel restrictions. These restrictions, indicated by tunnel codes, are designed to manage the risks associated with carrying hazardous materials through confined spaces where an incident could have catastrophic consequences.
The Code System
The tunnel code system uses letters from B to E to designate which dangerous goods can pass through specific tunnels. Each dangerous good is assigned a tunnel code in Column 15 of ADR’s Table A, and these codes tell drivers whether their load is permitted through particular tunnels. The system works on a sliding scale, where B is the most restrictive and E is the least restrictive.
How It Works in Practice
Let’s say you’re transporting flammable liquids with a tunnel code of (D/E). This means you cannot use tunnels categorised as D when carrying your goods in bulk, but you can use them when carrying the same goods in packages. The ‘E’ restriction applies to bulk carriage. This might seem complex at first, but it’s a practical system that helps manage risk while maintaining efficient transport routes.
Planning Your Route
Before setting out on any journey carrying dangerous goods, you must check your load’s tunnel codes and plan your route accordingly. Many satellite navigation systems now include tunnel category information, but it’s vital to verify this independently using official sources. The government maintains an up-to-date list of tunnel restrictions on major routes, and this should be your primary reference point.
The Impact on Journey Times
Taking tunnel restrictions into account may mean choosing alternative routes that add time to your journey. For instance, a direct route through central London might be unavailable due to tunnel restrictions, requiring a longer route around the outskirts. This additional time needs to be factored into journey planning and working hours calculations.
Seasonal and Time Variations
Some tunnels have different restriction categories depending on the time of day or season. This is particularly common in urban areas where traffic patterns vary significantly between peak and off-peak hours. Always check whether such variations apply to your route, as they could affect your delivery schedule.
Emergency Procedures
While tunnel codes primarily affect route planning, they also influence emergency procedures. Each tunnel has specific emergency protocols, and drivers must familiarise themselves with these before entering. The instructions in writing carried in the vehicle will include tunnel-specific emergency information that must be followed in case of an incident. Driving safely in a tunnel will reduce the chance of an incident occurring.
Looking to the Future
As infrastructure develops and risk assessments evolve, tunnel categorisations may change. It’s essential to stay updated with any modifications to tunnel codes or new restrictions. Regular checks of official guidance and attendance at professional development sessions can help ensure you’re always working with the most current information.
Remember, tunnel codes aren’t just bureaucratic hurdles; they’re vital safety measures that protect both drivers and the public. Understanding and correctly applying them is an essential part of professional dangerous goods transport.
Darren has owned several companies in the automotive, advertising and education industries. He has run driving theory educational websites since 2010.