GO Transit currently operates two types of buses: single-decker
highway coaches, constituting 75% of the active fleet; and commuter-type
double-decker buses, constituting the remaining 25%. All vehicles run on
diesel fuel. • The current highway coach fleet consists exclusively of
D4500-model coaches built by
Motor Coach Industries (numbered from 2100 onwards). The first of these coaches were ordered in 2001 and orders have continued until 2015. They have a length of . All orders since 2005 (from 2267 onwards) are of a facelifted design, designated as D4500CT, and two of these vehicles (3000 and 3001), ordered in 2008, have a
hybrid-electric drivetrain and are model D4500CTH. Older vehicles in the fleet are retired after reaching a certain mileage; as of 2017, the oldest vehicles in the active fleet were made in 2004. • The double-decker fleet uses
Alexander Dennis Enviro500s. They come in three distinct configurations, differing mainly in height and distinguishable external appearance: • The standard-height version (numbered in the 8000s) are in length and have a height of . Built in
Falkirk, Scotland, they entered service in 2008, but their height prevents them from meeting many height standards set by the provincial
Ministry of Transportation, restricting their usage to the Highway 407 and Highway 403 corridors, providing service between Peel and York Regions. • The
Go-Anywhere version (numbered in the 8100s and 8200s) are the same length, but have a shorter height of . This variant, also made in Falkirk, entered service in 2012, and their lower height allows these buses to meet many more clearance standards as a result and are used on a wider variety of routes, including those that travel on Highway 401 into Durham Region. • The
Super-Lo version (numbered in the 8300s) are longer than previous orders, at in length, but have an even shorter height of . Developed specifically for the GO Transit network, it is capable of accessing bus terminals with height restrictions that prevent previous double-deckers accessing them. They are also the first double-decker buses to be manufactured locally (from a newly established facility in
Vaughan). The first of these vehicles entered service in 2016 and orders are ongoing to replace older single-decker coaches. By 2020, Metrolinx estimates that 75% of the active fleet would be composed of double-deckers. In May 2023, GO Transit placed two electric buses into revenue service on a trial basis. They had been tested without passengers since December 2021. An electric bus costs $1.5million compared with $700,000 for a diesel bus; the electric bus has lower fuel and maintenance costs. Between charges, an electric bus can run about in winter and in summer; GO bus routes can be as long as . Battery charging takes 3–4 hours at garages.
Active AD =
Alexander Dennis; all buses are wheelchair accessible Image:GO Transit MCI D4500 2109.jpg|GO Transit MCI D4500 with original paint scheme Image:GO Transit MCI D4500CT 2267.jpg|GO Transit MCI D4500CT with original paint scheme Image:New GO Bus Design.jpg|Back view of the 2007 GO bus paint scheme back view Image:New Go Bus Design Front View.jpg|Front view of the 2007 GO bus paint scheme Image:GO Bus 2336 in new green.JPG|A D4500CT with the 2013 GO two-toned livery Image:GO Transit double-decker bus.jpg|Standard-height
Alexander Dennis Enviro500 Image:Go Transit 8129.jpg|Go-Anywhere height
Alexander Dennis Enviro500 Image:GO Transit SuperLo Enviro500 8308.jpg|Super-Lo height
Alexander Dennis Enviro500 Image:GO Bus 5018 MCI D45 CRT at Oshawa GO, March 18 2026.jpg|
MCI D45 CRT Retired Previously, GO Transit also operated suburban-style
transit buses from
General Motors,
Orion Bus Industries, and
New Flyer Industries, and motor coaches by
Prevost Car. GM buses (except for Suburbans) were manufactured in
London, Ontario and Orion buses in
Mississauga, Ontario. All of these older vehicles are now retired. ==Support vehicles==