WASHINGTON — As derailment repairs continued through Tuesday morning, nearly nine out of 10 Red Line riders were late. But it’s unclear whether they would get refunds under a new “Rush Hour Promise” policy the Metro Board is due to adopt next week.

“As we announced well in advance, Red Line service would be significantly reduced …. during the morning commute due to ongoing repairs,” Metro spokesperson Sherri Ly said in an email. “Not surprisingly, only 12 percent of AM Peak trips on the Red Line arrived on time.”

A number of riders described trips that took an hour or more longer than usual as they struggled to squeeze in on packed trains. Repairs were completed in time for Tuesday afternoon’s rush hour.

The details of the refund policy set to be approved by the full Metro Board next week are still being finalized, but it is expected to include refunds to rush hour rail riders who arrive more than 15 minutes beyond Metro’s maximum expected time for a trip from tap in to tap out except in situations like 24/7 shutdowns, when disruptions are announced in advance.

Because the policy has not been finalized, it is not clear whether Tuesday’s rush hour would count as a situation where riders had enough notice of the potential delays. Had Monday not been a holiday, the refund policy would have applied then to riders delayed more than 15 minutes during the rush hour periods.

Even including Tuesday morning’s Red Line issues, Metro found 80.1 percent of riders Tuesday arrived on time under the measure that includes time to walk to and from the train in stations, the maximum scheduled wait for a train at that time of day, and the scheduled travel time. An additional 7.1 percent of riders Tuesday arrived within 5 minutes of the expected time, Ly said.

On other lines Tuesday, which were unaffected by the derailment, 96 percent of Green Line riders were on time, 93 percent of Yellow Line riders were on time, 88 percent of Orange Line riders were on time, 85 percent of Blue Line riders were on time, and 83 percent of Silver Line riders were on time