Honolulu Mayor Kirk Caldwell vetoed a bill Friday that would have prohibited the administration from implementing bulb-outs, essentially curbside extensions, at five Chinatown locations.

Bill 82 passed by a narrow 5-4 margin during a May 9 Honolulu City Council meeting, so it’s unclear whether Council leadership would be able to muster the six votes needed to override the veto.

Bulb-outs are part of the Complete Streets ordinance adopted in 2012 by the City and County of Honolulu with strong Council support. Complete Streets aims to create a transportation network that safely accommodates foot, bicycle, mass transit and automobile traffic.

Caldwell said in a statement he was vetoing the bill because city directors attested to the success of curb-extension bulb-outs during a 10-month pilot project in Chinatown that saw a reduction in motor vehicle collisions with pedestrians.

Further, the mayor said the bill “infringes upon the specifically enumerated executive functions” of several city directors and violates the “separation of powers” principle.

Councilwomen Carol Fukunaga and Ann Kobayashi introduced the bill in response to complaints about the pilot program. A common criticism was that bulb-outs have added to street congestion, interfered with deliveries and caused sales to drop because customers can’t park in front of stores to make quick pickups. There also have been complaints that homeless people have turned them into living spaces.

Another group of merchants, residents and Chinatown visitors have supported bulb-outs because they say extending the sidewalks and reducing crosswalk distances slows down traffic and makes crossings safer for pedestrians.