What can happen if you underestimate the posted height at a bridge?

Underestimating the posted height at a bridge can lead to a collision with the bridge itself, which is why the first choice is correct. When drivers fail to pay attention to these height restrictions and assume their vehicle can safely clear the obstruction, they risk serious damage to their vehicle and the bridge. This can result in dangerous situations not only for the driver but for other road users as well, potentially leading to accidents or traffic disruptions.

The other choices describe situations that may not directly relate to underestimating the height. For instance, driving faster than allowed, receiving a traffic citation, or having to reverse are all scenarios that do not address the immediate consequences of misjudging the clearance of a bridge. Safety measures, like respecting posted height limits, are crucial to prevent accidents and ensure safe travel.