London Buses route K4 is a Transport for London contracted bus route in London, England. Running between Mansfield Hospital and Kingston Hospital, it is operated by London United.
Route K4 was introduced on 2 December 1989 between Kingston Bus Station and Hook via Cromwell Road - Queen Elizabeth Road - London Road - Wheatfield Way - Ashdown Road - Eden Street - St. James Road, ( return via Brook Street - Eden St and Clarence St ) Penrhyn Road - Surbiton Road - Surbiton Crescent - Claremont Road - Surbiton Station,Victoria Road - Brighton Road - Upper Brighton Road - Hook Road - Ace of Spades - Hook Road - then a one way loop via Mansfield Road - Woodgate Avenue - Stormont Way - Holsworthy Way - Hereford Way - Ripon Gardens - Woodgate Avenue - Clayton Road. It was initially operated by Westlink from their Kingston (K) garage using MCW Metroriders.
On 28 August 1993, the route was rerouted between Kingston and Surbiton via Villiers Roadand St. Marks Hill instead of Penryhn Road - this was an exchange with the K3 routeing.
On 2 September 2000, the route was extended from Kingston to Kingston Hospital.
On 30 June 2001, the route was retained by London United. A hourly evening service was introduced and the route was withdrawn between Kingston and Kingston Hospital and this section was replaced by Route K2.
In November 2001, the route was converted to low floor operation using Plaxton Pointer 2 bodied Dennis Dart SLFs.
On 3 November 2001, Kingston (K) garage was announced closed and the allocation was transferred to Tolworth (TV) garage.
On 19 March 2005, the route was extended from Kingston to Kingston Hospital.
On 1 July 2006, the route was retained by London United.
On 29 June 2013, the route was retained by London United with Alexander Dennis Enviro 200 Darts introduced.
Route K4 operates via these primary locations:
- Mansfield Estate Ripon Gardens
- Winey Park
- Surbiton Station
- Kingston Station
- Norbiton Station
- Kingston Hospital