When Pan Am Games athletes touch down at Toronto’s Pearson Airport in two years, they’ll have a new way to travel to downtown.

The Union Pearson Express (UPE) — an airport train linking Pearson's Terminal One with Union Station — is currently under construction with a goal to have the train on the rails in time for the 2015 Games.

Critics have long pointed to Toronto’s lack of a dedicated airport rail link, something many cities similar in size already have.

While not officially a capital project of the Pan Am Games, the UPE is being billed as a key component of the city’s transportation network with the Games expected to bring about 250,000 visitors to the city.

"The Union Pearson Express will provide thousands of spectators and participants from around the world with a new experience — a warm and convenient first welcome to our city and province," reads a statement on the UPE website.

A trip between Union and Pearson's Terminal One will take 25 minutes on the new train, with departures every 15 minutes. The train will offer connections to the Weston and Bloor GO stations.

Trains will also feature special airport luggage racks, washrooms and Wi-Fi.

That’s a big upgrade from the TTC’s Airport Rocket service, which takes about the same amount of time to travel by bus between the airport and Kipling Station, located at the western end of the Bloor-Danforth subway line.

The hope is that UPE will trim the number of car trips between the airport and downtown — currently pegged at five million a year — by 1.2 million trips by 2020.

The airport train has its critics. Some have said the $456-million cost is too high. Citing health concerns about pollution, a group of west-end residents are unhappy the trains will be operated by diesel locomotives.

The province has committed to an environmental assessment that will study electrifying the line, but that study won’t be completed until 2014.

Others have wondered about how much a ride will cost (Metrolinx has yet to specify a fare structure), though some reports estimate a one-way ride will cost $20.