The first train on the Union Pearson Express line left for Pearson International Airport at 5:30 a.m. Saturday, marking the official opening of long-awaited and still-controversial rail line.

The express line connects travellers between Union Station in Toronto's downtown core and the airport in 25 minutes for $27.50, or $19 for those with a Presto fare card.

It makes two stops along the way, at the Bloor and Weston GO stations. Trains depart every 15 minutes.

Chris Drew, a downtown resident, was one of the first riders on the train heading to Pearson.

"It's great for Toronto. New things are always good," he told CBC Toronto.

Although some people will still travel to and from the airport by TTC, taxi or car, Drew said the rail line offers another option for commuters.

The food and beverage service on the train, as well as free Wi-Fi, are also the bonus, Drew said.

"There are a lot of perks that make it an enjoyable ride," he said.

Sound walls delayed

Combined, Union Station and Pearson see some 100 million passengers per year.

Critics have said fares for the UP Express are too expensive, but officials at the transit authority Metrolinx have defended the cost by comparing the new rail line to other transit options to the airport, such as taxis and the TTC.

The Union Pearson Express travels between downtown and the airport, with departures every 15 minutes. The warning bells that sounds each time it approaches Bloor Station are annoying some residents in the area. (Mike Cole/CBC) Some residents along the line say Metrolinx has not put up sound walls, as promised, to dampen the noise.

The frequency of the trains is the issue, said homeowner Steve Reble, whose home near Lansdowne Avenue and Dundas Street West backs onto the tracks.

"Metrolinx lacks the commitment to promises it's made," Reble said Friday on CBC Radio's Metro Morning.

Metrolinx CEO Bruce McCuaig said construction of some sound walls was delayed by both the harsh winter and the time it takes to work out details like property lines with homeowners.

McCuaig said the remaining walls should be up by late summer or fall.

"We're committed to completing those noise barriers," he said.