[10] The plan to close the remaining tram lines was put on hold because of the outbreak of World War II in 1939; they were powered by electricity generated by British coal, whereas the buses relied on imported fuel.

[11] A large part of the population of Plymouth moved out to the relative safety of the countryside during the war which meant that the Corporation's buses and trams were carrying fewer passengers, but rival Western National was under increasing pressure.

Both operators had suffered damage to their depots and fleet – Milehouse was bombed in April 1941 – and so the two companies decided to pool resources under a Plymouth Joint Services agreement.

[11] The Plymouth Joint Services agreement remained in place after the war, enabling both the Corporation and Western National to serve new housing estates that sprang up around the edge of the city.

[12] The routes in the Joint Services area, including those of Western National, were renumbered in a single sequence from 1 to 57 in 1957.

Early interest came from FirstGroup and local taxi owner John Preece[21] who had been behind the privatisation of Western National and had made previous attempts to purchase Citybus.

[23][24][25] As of October 2013, Plymouth Citybus employed 443 people, operated 151 buses and coaches, and carried about 14 million passengers annually.

Plymouth City Transport's first coach-seated vehicles was a Leyland National fitted with coach seats.

[29] A separate unit branded 'Plymouth Citycoach' was later created Citybus with its own management and a remit to produce a profit.

[citation needed] The Liskeard-based operations of Western Greyhound were purchased on 8 December 2014 with 9 Optare Solo buses and relaunched as Go Cornwall Bus.

[31][32][33] It was announced on 6 January 2020 that Cornwall Council had awarded the entire tendered county bus network (except the Truro Park & Ride) to the Go-Ahead Group from 1 April.

FirstGroup subsidiary Kernow retained the Truro Park & Ride contract and will continue to run their commercially-operated routes.

The Red Flash being the 21/21A service between Barne Barton and Chaddlewood, BlueFlash being varying guises of the 42's services to Tamerton Foliot, Derriford, Woolwell & Tavistock using both Enviro400 & Wright Eclipse vehicles, then the 11 between Plymouth and Bodmin, in Cornwall, repurposing the Wright Eclipse single-decks.

GreenFlash was the name given to the commuter services 8/9 and 23/24 between the City Centre and Efford and Mount Gould, as well as the 5/A/B/C serving Plymstock.

[29] These allowed narrow housing estate roads to be served and service frequencies to be increased on existing routes.

Mid-size single deck buses replaced most double-deck vehicles on busier routes to give high service frequencies, principally Dennis Darts.

[36] Plymouth City Tramways initially used a maroon colour scheme but a yellow and white livery was introduced in 1922[7] although some had varnished teak bodies.

[29] A new image (designed by Ososki Graphics of Exmouth) was introduced to coincide with the revised Plymouth Joint Services network in 1982.

The new 'Plymouth City bus' logo was placed on the cream below the windows near the centre of each side; 'city' was red and the other words black.

[20] Park and ride services were introduced using Mercedes-Benz minibuses in a mid-grey scheme[8] but the Dennis Dart MPDs that replaced them were given special green and yellow livery.

Following the takeover by Go Ahead in 2009, Best Impressions designed a two tone red livery with a white 'swoosh', this accompanied a new version of the Plymouth CityBus logo.

However this has since been adapted by the company, who now use a plain red with a different style of swoosh (which covers more of the bus) and a simplified version of the Best Impressions devised logo.