Ottawa’s O-train is back on track after a four-month service disruption.

The stoppage allowed $59-million in upgrades to be done to the rail service over the summer. Many were happy to be back on the train.

“I took the 107 over the summer and it was just so slow,” says Chris Mariano who used the alternative bus route during the disruption.

But others were hoping for an immediate improvement in service after an entire summer without the O-Train.

New passing tracks and platforms have been added to the O-Train line to accommodate the newly purchased O-Trains. Still, the trains provided by Alstom will not be ready to hit the rails until September 2014. The added trains will reduce wait times to 8 minutes from the current 15 minutes.

“There is rigorous testing that has to occur and the new service has to meet before we can actually start the service of the Alstom trains,” says Ottawa Transit Commission chair Diane Deans.

Deans also apologizes for delays felt Tuesday as the O-Train service were brought back online. Some riders complained of having to wait upwards of 20 minutes.

“There was a little bit of a slowdown of the service, which is part of the normal resumption of the service,” says Deans.

Deans says any future O-Train disruptions will be minimal with testing done during evening non-peak hours.

With a report from CTV’s John Hua