Oregon voters Tuesday approved a constitutional amendment requiring cars and trucks to pay their fair share of highway construction and maintenance costs. It’s unclear how the vote will affect a spring referendum that would raise the gas tax and do away with the state’s weight-distance tax.

The tax change was supposed to go into effect Nov. 1, but opponents of the measure gathered enough signatures on a petition to send it to the voters next May.
Supporters of the new tax say the constitutional amendment, Measure 76, will help the gas tax measure win with voters.
Opponents, however, say it won’t be any help, because voters will know it gives trucks an unfair tax break. Polls have indicated strong opposition to the gas tax increase.