Some Northstar riders got a free trip Friday morning because of a delay that forced Metro Transit to make good on its money-back guarantee for January.

This is the first time Metro Transit has had to ante up since it launched its money-back promotion, which gives riders a refund when trains arrive at the station 11 or more minutes late.

"We've been excited up until now that we've been on time," said spokesman Howie Padilla. "We are disappointed this happened today, but we will make good on our word to those who registered and refund their trip."

A switch issue near Big Lake caused two runs on the commuter line to arrive at the station late. A reverse trip from Minneapolis to Big Lake and the fifth and final inbound trip from Big Lake to Target Field arrived more than 10 minutes behind schedule. The last inbound trip left Big Lake at 7:43 a.m. and got to Target Field 25 minutes late, said Padilla.

Metro Transit will issue refunds to customers who registered for the on-time promotion and paid with an electronic fare card. Cash-paying customers do not get a refund.

The agency started the promotion in hopes of wooing riders back to the train after numerous delays last winter led to a drop in ridership.

It was not immediately clear how many riders were on Friday's trips nor how many riders were eligible for a refund.

Tim Harlow • 612-673-7768