number of Dennis Dart single deckers, to free up double-deckers for the conversion of routes 139 and 189 to double-deck. However, full double-deck operation was returned by 17 February 2003, when the Mayor's congestion charge began. In 2007, the Monday-Friday peak service was reduced slightly, with the introduction of a new route 332, which incidentally replaced the 316 between Cricklewood and Neasden, that route having been introduced to replace the same section of route 16 ten years earlier. Another change to vehicle type occurred in mid-2008, when Alexander Dennis Enviro 400 double-deckers were introduced. These buses were bought for the new contract on route 460, but were instead allocated to Cricklewood Garage, in order to compare their performance with the earlier batch bought for route 332 and hybrid versions due for trial. New Routemasters were introduced on 26 September 2015. The rear platform remains closed at all times except when the bus is at bus stops. In 2021, the frequency of the service was reduced from 8 buses per hour to 6 during Monday-Saturday peak times, and from 6 buses per hour to 5 at other times. On 23 November 2022, it was announced that route 16 would run between Paddington and Brent Park, fully replacing route 332, following a consultation that proposed that it would be withdrawn. This change will be implemented by the end of 2023. Express Route 616 Route 616 began operating on 15 June 1970 as an express service for route 16, running between Cricklewood and Oxford Circus, Monday to Friday, but later reduced to peak hours only, before being replaced by route 16A in 1976. Route 16A Route 16A replaced the express route 616 on 31 January 1976, but running between Victoria Station (not Oxford Circus as route 616 had) and Brent Cross via Edgware Road, Cricklewood Broadway and Staples Corner, Monday to Saturdays. The route was changed from one-man operation to Routemaster operation for a period between 1980 and 1987. The route was diverted in 1981 at Marble Arch to serve Oxford Circus once again. In 1991, the evening service ran between Brent Cross and Kilburn Park Station, although by 1994 the route was running between Brent Cross and Oxford Circus during daily (including Sundays) shopping hours. On 10 October 1997, the route was withdrawn, being partly replaced by new route 189, running via Abbey Road and Baker Street. Current route Route 16 operates