Line 4 (O-Train)

Line 4
Overview
Status	Open
Owner	City of Ottawa
Locale	Ottawa, Ontario
Stations	3
Website	OC Transpo (Line 4)
Service
Type	Light rail
System	O-Train
Rolling stock	Alstom Coradia LINT
History
Opened	January 6, 2025 (2025-01-06)
Technical
Line length	4 km (2 mi)
Track gauge	1,435 mm (4 ft 8+1⁄2 in) standard gauge
Route map South Keys Uplands Airport

Line 4 (also known as the Airport Link) is a light rail line on the O-Train network in Ottawa, Ontario. The line provides a connection between the Trillium Line (Line 2) at South Keys station to the Ottawa Macdonald–Cartier International Airport. The four-kilometre (2.5 mi) line opened on January 6, 2025.

The line uses a fleet of Alstom Coradia LINTs, a diesel multiple unit that was originally used on the Trillium Line. The Line 4 trains are shorter than those used on other O-Train lines due to the line's low projected ridership; the station were also built with shorter platforms.

History

In 2016, the Ontario provincial government commited $1 billion to O-Train expansion which funded the line to the airport. Construction of the line began in 2019.

Stations

Main article: List of O-Train stations

Station	Notes
South Keys	The northbound terminus; this station provides an interchange with the Trillium Line (Line 2) in a fare-paid zone and access to the Transitway nearby.
Uplands	Located east of Uplands Drive next to the EY Centre and will feature two platforms. It is the location of the only passing loop on the line.
Airport	The southbound terminus; it is located at the Ottawa Macdonald–Cartier International Airport and built into the renovated and expanded terminal at the departures level.