A closer look
One catastrophic inferno permanently changed how Europe routes highly explosive materials. After the devastating 1999 Mont Blanc Tunnel fire, traffic engineers stopped letting trucks full of toxic chemicals casually roll through massive underground tubes. Today, ADR regulations strictly categorize tunnels from A to E. If a tunnel is slapped with a strict Category E rating, virtually all hazardous cargo is forced into massive, costly surface detours over the Alps, treating these underground spaces as the ticking time bombs they actually are.
