PORTLAND – No one knew whether Amtrak’s Downeaster would be a success when it departed Portland with its first passengers five years ago on a dark, rainy morning.

More than 1.4 million passengers later, the Downeaster is one of Amtrak’s most successful trains with ridership growing 31 percent in the last fiscal year.

“I don’t think that five years ago people thought it would be this successful,” said Patricia Douglas, executive director of the Northern New England Passenger Rail Authority.

On Friday, the Northern New England Passenger Rail Authority marked the Downeaster’s 5th birthday with cake and the arrival of a train carrying Santa and 120 children from Berwick and Scarborough who donated toys to the Toys for Tots Program.

Also, volunteers were at each of the Downeaster’s train stations handing out cookies and commemorative pins marking the occasion, she said.

In the coming year, operators hope for further ridership gains once track upgrades are completed, allowing the train to make five daily runs.

Beginning last month, Amtrak began using buses for a fifth daily round trip between Portland and Boston. The train had four daily runs when it started.

The track work that’s currently under way involves new sidings to allow freight and passenger trains to move around each other, Douglas said.

While successful, the Downeaster still relies on federal and state subsidies. This year, the federal government provided a $5.3 million grant, and the state provided $1.6 million.