PROVIDENCE, R.I. — Free trains are running to one of the most popular events of the summer, the Rhode Island National Guard Open House and Air Show.

The show is Saturday and Sunday at the Quonset Business Park in North Kingstown.

Traffic typically becomes heavily congested. Organizers say the show attracts about 90,000 people.

The state Department of Transportation worked with the show’s organizers to offer free trains to get to and from the event.

Attendees can park for free and catch the train at the Providence Station, T.F. Green Airport station in Warwick or Wickford Junction Station in North Kingstown.

This year there will be twice as many trips scheduled.

There will be three trains from each station. The schedule can be viewed online .