Why is it especially important to keep large following distances when hauling hazmat?

Following distance for hazmat vehicles should be larger than for general freight for two reasons. First, the vehicle is typically loaded heavily (gasoline tankers, chemical bulk loads) and takes longer to stop. Second, the consequences of being rear-ended into the vehicle ahead, or rear-ending another vehicle, are much greater — a fuel spill from a ruptured tanker creates immediate explosive fire hazards over a large area. The standard 'one second per 10 feet of vehicle length' is the floor; experienced hazmat drivers add another 2-4 seconds, especially in heavy traffic or adverse conditions. The goal is to give yourself enough time to slow gradually without panic braking, and to avoid being caught up in chain-reaction crashes ahead.