Free wireless service is now standard for passengers on Amtrak's Acela Express trains.

Amtrak made the announcement Tuesday, following a three-month trial run in which all 20 of Amtrak's Acela Express cars provided free service. Amtrak says about 115,000 passengers a month have used the service, or about 39 percent of ridership. It plans to expand the wireless service to other routes starting in late fall.