What Are FD Blockers and How Could They Enhance Road Safety

Fixed and mobile blocker vehicles shield crews and equipment the way a TMA shields a work zone. Here is where they fit in a safety plan.

A blocker vehicle sits between traffic and whatever needs protecting, a crew, a piece of equipment, or a gap in the barrier. The idea is the same one behind a truck-mounted attenuator: put a sacrificial, energy-absorbing vehicle where an errant driver would otherwise hit people or hardware.

How blockers support a work zone

• They create a physical buffer between live traffic and the crew.
• They can carry an attenuator, arrow board, or message board to warn and protect at once.
• They give a mobile operation protection that moves with the work.

Pairing blockers with attenuators

A blocker is most effective when it carries a MASH-compliant attenuator rated for the work-zone speed, TL-2 below 45 mph and TL-3 at 50 mph and above. The attenuator handles the impact, the boards handle the warning, and the truck weight keeps the whole assembly in place. Used together, they cover the seconds before a crash and the impact itself.