School bus guidance puts a gap of at least 10 feet between the bumper and the children waiting at a stop. What is that gap for?

Explanation

The gap is there to make the children cover the last stretch on foot, which keeps them moving in front of the driver instead of bunched where the driver cannot look. A group pressed up against the bumper occupies the one patch of ground no mirror and no glance will reach, and a child who bends down or steps forward there vanishes outright; the same children walking that last stretch can be watched, counted, and accounted for. The wrong options each swap a plausible mechanical or traffic rationale for what is really about being able to see. The crossing control arm's travel is not what fixes where the bus halts, pulling up short does not move the bus clear of a side danger zone that is measured outward from the bus itself, and how well following traffic can see the extended stop arm turns on where the bus sits in its lane, not on its distance from the children. 49 CFR 383.123(a)(2)(i) makes loading and unloading children a required knowledge area but fixes no stopping distance, so the figure and the reasoning behind it are attributed to the manual.

Source: 49 CFR 383.123(a)(2)(i)