Your analysis of slowing buses in global cities sets out the mechanism exactly, and the remedy follows from it (London buses in decline? Why public transport in global cities is slowing to a crawl – visualised, 23 September).
Transport for London’s own calculation that a 10% fall in speed costs 6% of demand and Imperial College London’s finding of the same decline across 15 cities show what happens to buses as the traffic thickens around them. Retiming the lights will not reverse it, and London is already trying. The phrase to notice in the article is one used by TfL: signals will give more buses priority “where possible”.
