Some Northstar riders got a free trip Friday morning when 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 behind schedule. The last inbound trip left Big Lake at 7:43 a.m. and got to Target Field 25 minutes late, said spokesman Howie Padilla.

That means riders who had signed up for Metro Transit's on-time guarantee promotion will get their fares refunded. The agency started the promotion Jan 1 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 to get a refund. To get a refund, customers had to have paid with an electronic fair card and be registered with Metro Transit. Cash paying customers will not get a refund

This is the first time Metro Transit has had to ante up since it launched its money-back guarantee. The promotion runs through Jan. 31.

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