Auckland Transport is adapting big rubber speed humps to act as barriers to keep double-decker buses away from roadside hazards.
The agency said the $35,000 being spent on the impromptu barriers was cheaper than cutting back trees and verandahs which could be hit by the buses on new suburban routes.
It insisted the impromptu kerb-extenders would not make it harder to get on and off buses at stops, and that they would not clog gutters when leaves fall.
The humps are being installed on Mayoral Drive, Hobson Street and Albert Street, ahead of the introduction of double-deckers on the western Route 18 in just under a fortnight.