Starting July 1, up to 5,000 volunteers in Oregon can sign up to drive with devices that collect data on how much they have driven and where. The volunteers will agree to pay 1.5 cents for each mile traveled on public roads within Oregon, instead of the tax now added when filling up at the pump.

Some electric and hybrid car owners, however, say the new tax would be unfair to them and would discourage purchasing of green vehicles.

“This program targets hybrid and electric vehicles, so it’s discriminatory,” said Patrick Connor, a Beaverton resident who has been driving an electric car since 2007.

State officials say it is only fair for owners of green vehicles to be charged for maintaining roads, just as owners of gasoline-powered vehicles do.