[Petronski]

Consider this, a car has a footprint of around 45-50 square feet while a person has a footprint of around one square foot and weighs 150 pounds.

Huh? 45-50 sq ft? 10-12 sq ft per tire? I'd say you're off by a factor of five, at least.

OTOH, I could see how walking would be heavier than the same weight on a vehicle in part because the body is falling with each step, not rolling on a tire.

[dirtboy]

OTOH, I could see how walking would be heavier than the same weight on a vehicle in part because the body is falling with each step, not rolling on a tire.

They were turning back small groups. This wasn't about bridge safety.

[IronMan04]

In addition the cadence of footsteps across a bridge can cause vibrations which the bridge would not be rated for.