Parents who want to drop their children off by car are now banned from driving within 300 yards of the primary schools in Haddington, East Lothian. It followed cases of "irresponsible" driving near schools.
East Lothian Council now only allows local residents and Blue Badge holders to use the roads outside the primaries during the morning and afternoon drop-off and pick-up.
The 18-month trial ban came into effect yesterday and could be rolled out elsewhere if it proves successful.
The scheme affects King's Meadow Primary, Haddington Infant School and St Mary's Roman Catholic Primary, in the south of the town.
The council's transport leader Michael Veitch said: "Unfortunately, at peak periods, a small number of drivers continue to drive or park irresponsibly too close to schools, which has led to the introduction of this trial on the cul-de-sac roads leading to the town's infant and primary schools."
East Lothian Council is thought to be the first local authority in the UK to take such a step.
But Neil Greig, director of policy and research at the Institute of Advanced Motoring, said the ban may in fact lead to drivers speeding up around schools.
He said: "The main issue is it risks shifting the problem further away.
"There's no evidence at all that school gate parking actually causes injuries."