TRL report "Impacts of motorcycles in Westminster bus lanes" 2008
TRL report 2008
Impacts of motorcycles in Westminster bus lanes 
Transport Research Laboratory report which produced no statistically robust conclusions. No major concerns emerged, but motorcyclist behaviour (e.g. lane discipline) and certain site characteristics (high flows and a large number of side roads) were identified as potential problems. Roads with high numbers of junctions and high numbers of bus and taxi movements to the kerb were identified as potential issues by the study.