Tolls may be coming to interstate highways in the Portland area in a few years, and the mere idea has opponents rushing to file a ballot measure aimed at stopping them.

State Rep. Mike Nearman, R-Independence, and Les Poole, a Gladstone planning commissioner, have filed preliminary paperwork to place a constitutional amendment on the 2020 general election ballot. If they succeed, voters will be asked to amend the constitution to require a statewide vote on most proposals to impose new fees or tolls on users of “transportation infrastructure” — roads and bridges — anywhere in Oregon.

It’s a bad idea.

Oregon’s ability to maintain, much less enhance, the state’s highways and bridges is at best just holding its own, even as the population and vehicle usage increase.

The federal government does not pick up the entire tab. Too, while increasingly fuel-efficient vehicles may be good for the environment, they cut into the amount of money state and federal fuel taxes generate.

Oregon lawmakers took steps to improve the situation last year, when they approved a $5.3 billion transportation package that raised fuel and registration fees and created a payroll tax, among other things. The bill also required the Oregon Department of Transportation to consider tolling in the Portland area to reduce congestion and help finance new projects as they’re needed.

The proposed constitutional amendment could derail that project and make it nearly impossible to get it back on track. That despite the fact that tolls on Portland roads would, in fact, apply only to those who use those roads.

Oregon must find ways to build and maintain the transportation infrastructure it needs, and the proposed user fees would help that cause. If the proposed petition gets to the ballot, it should be defeated.