Premier Dalton McGuinty’s money-back guarantee to GO Transit riders will kick in this fall, the government announced Monday.

If a GO train is more than 15 minutes late, commuters will be eligible for a refund on their fare.

But the government, which didn’t specify a date, has left itself lots of outs. The guarantee won’t apply to delays caused by extreme weather, police investigations, accidents and medical emergencies, meaning quite a few late trips will be exempt from the policy.

It is, however, a little more generous than the premier’s original proposal last June when he floated the guarantee for 20-minute-or-more delays.

Metrolinx CEO Bruce McCuaig estimated at that time that the refund policy would cost between $6 million and $7 million annually.

Some 640 of GO’s 54,000 train trips last year had delays of 15 minutes or more. Of those, 565 trips would have qualified for refunds under the new program, according to Metrolinx spokesman Malon Edwards.

Despite Duguid’s comments, Metrolinx estimates the guarantee would cost only $7 million annually.

McGuinty said the policy was an extension of other money-back promises for government services such as birth certificates.

GO’s latest report suggests that 95 per cent of its rush-hour trains run within five minutes of scheduled service and only 1 per cent of trips are cancelled or delayed more than 20 minutes.

GO carries about 62 million riders per year with about 75 per cent of that on trains. Each 12-car train carries about 1,600 people.