Bus speeds are declining in London and other global cities, with Transport for London (TfL) calculating that a 10% reduction in speed results in a 6% drop in demand. Imperial College London has identified a similar decline across 15 cities.
Efforts to retime traffic lights to give buses priority in London have not reversed this trend. TfL notes that signals provide bus priority "where possible," highlighting a limitation in congested areas.
Bristol City Council engineers observed that bus priority measures delivered no journey-time saving in the most congested parts of the city. This issue is suggested to hinder urban economies by making it harder for people to travel for work, customers, and shopping.
One suggestion for improvement is the use of trams, which can carry the same number of people as three or four buses. This allows for consistent priority at junctions without significantly impacting other traffic. Approximately 30 French cities have introduced trams through their centres since 1985, reportedly making central streets busier.
Concerns have also been raised regarding the replacement of dedicated bus lanes with cycle lanes in London, particularly given the city's narrow roads. It is suggested that this prioritisation of individual cycle transport over mass public transport has contributed to buses becoming slower and less reliable.