The question of letting heavy commercial trucks use all of Maine’s interstate highway system has been bouncing back and forth in Washington for years.

And the ones paying the price for current rules banning trucks weighing 80,000 to 100,000 pounds from interstate roads that are not part of the Maine Turnpike are the communities whose side roads and main streets the trucks must use instead.

It’s time to settle this question once and for all. Therefore, Maine Sen. Susan Collins is to be commended for getting a Senate committee to include in its transportation spending bill for 2012 a plan to get heavier tractor-trailers back on the roads that are best-suited for their use.

Similar measures have been sponsored or supported by the other members of the state’s congressional delegation. A bill submitted by Rep. Mike Michaud has 54 supporters in the House, but is not yet in that chamber’s budget.

Getting the trucks off the streets and onto the highways is blocked by federal transportation law, but New Hampshire and Massachusetts already have waivers that permit it, giving them a competitive advantage over Maine businesses that depend on trucking.

Collins’ bill would extend the same benefit to Maine and Vermont. The reason the turnpike is exempt is that Maine law governs its traffic, but once trucks cover the road’s 100-mile stretch from Kittery to Augusta and reach the federally controlled four lanes, they are dumped onto other roads.

Opponents of the change say the big trucks are too damaging to the road surface and bridges, but how much more harm are they doing now to the streets of our towns and cities?

Indeed, the interstates are the roads best suited to heavier vehicles, and they should be permitted to cover as much of their routes on them as possible. They had that permission for a year, under a trial exemption sponsored by Collins, but that expired last December.

Sen. Olympia Snowe has submitted a bill to let states seek waivers from the secretary of transportation rather than require changes in the law for each one, which would also work.

Either way, towns and cities north of Augusta shouldn’t have to bear the noise and wear that larger trucks are bringing them now.