The bill is in for Metro Transit's Service Guarantee Program on the Northstar commuter line, and the agency will be sending checks to riders totaling about $2,200.

In January and February, Metro Transit promised Northstar riders it would refund their fares if trains arrived at the station 11 or more minutes late. During the two-month promotion, 13 trains arrived more than 11 minutes late. More than 800 riders signed up for the promotion, and 402 will be reimbursed, said Metro Transit spokesman Howie Padilla.

Riders who paid cash or did not register for the promotion were not eligible for refunds. The promotion was launched to win back riders who stopped riding the train between Big Lake and Minneapolis last year after many deemed the service unreliable.

Ridership dipped in 2014 due to scores of late trains caused by repeated mechanical issues, harsh weather conditions and track maintenance, the agency said. Northstar's 2014 performance through October 2014 showed that trains were on schedule only 65.7 percent of the time, and through November ridership was 670,907, a dip of 10 percent from 2013.

Padilla said the promotion helped bring some riders back. More than 100 riders using newly purchased Go-To cards were counted, including roughly 30 who had not previously taken Northstar.

"We wanted to show that we could provide reliable service during the worst months," he said. Even though the promotion has ended, "that does not mean we are any less committed to providing reliable service."