Route 18, running between Sudbury and Euston bus station is the busiest bus route. The service carried over 16.6 million passengers in 2018/19. The next busiest routes (over 10 million) are: 25, 29, 140, 149, 243, 207, 86, 36, 38, 5, 279, 53, 109, 141 and 43.