For which type of material must vehicles maintain a distance of 300 feet from bridges, tunnels, or buildings?

The requirement for vehicles carrying Division 1.2 and 1.3 materials to maintain a distance of 300 feet from bridges, tunnels, or buildings is due to the dangerous nature of these materials, which are classified as certain types of explosives. Division 1.2 materials are explosives that have a projection hazard, and Division 1.3 materials are those with a fire hazard that also present a minor explosive hazard. These materials can pose a significant risk in the event of an accident or explosion, making it essential to keep a safe distance from structures that may amplify the consequences of an incident.

The 300-foot distance is a safety measure meant to protect both the general public and infrastructure in areas where a catastrophic failure could occur. In contrast, other material categories like flammable liquids, non-toxic gases, and corrosive materials have different safety protocols and distance requirements that do not align with the specific risk potential associated with Division 1.2 and 1.3 materials.