The City Council is looking at a plan that would require all public and private properties with elevated pedestrian walkways and parking garages to have higher fences.
The plan aims to prevent incidents such as when a brick was thrown off an overpass, striking a bicyclist in the face in Fort Greene last August.
The Department of Transportation says that the plan is too broad, lengthy and expensive to implement.
The council says it is willing to work with the city to make some cost-cutting concessions to get the plan passed.