A bike lane is a designated portion of a road reserved for bicycles, marked with paint, signs, or physical barriers to separate cyclists from motor vehicle traffic. Bike lanes range from simple painted lines to fully protected lanes with physical separation. They are part of municipal efforts to encourage cycling as sustainable transportation, improve cyclist safety, and reduce traffic congestion. Bike lane installation can be controversial, sometimes reducing space for cars or parking. Research generally shows protected bike lanes significantly improve cyclist safety and increase cycling rates, though debates continue about implementation approaches and priorities.