For 40 years, Mainers have been arguing that the state needs an east-west highway. Now we are arguing about whether the project needs another feasibility study.

It’s hard to believe that the idea hasn’t been studied enough yet. There have been passionate advocates for building this road, and plenty of analysis about its supposed benefits. The question always has been what it would cost and who would benefit.

At issue this time is a proposal from private interests, led by Peter Vigue of Cianbro Corp., who envision a privately funded toll road that would run from Calais to Coburn Gore, creating a straight shot for truckers moving goods between New Brunswick and Quebec.

Tolls collected from those truckers would help pay for the road, which also would provide tourists with a fast way to reach northern and Downeast Maine, and boost all kinds of commerce in some of the most economically disadvantaged parts of the state.

It’s an argument that we’ve heard before, but some basic questions are still outstanding.

The first is whether there are investors interested in funding this project, since it’s clear that the state and federal governments have not stepped up in the last four decades.

Why should the state pay for a study to help a private company decide if a private business investment is feasible?

Typically, the state requires developers to pay for their own studies when they apply for permits, even when those projects are expected to deliver a significant public benefit.

Regardless of the route, building a new highway would result in a significant environmental impact; and if demonstrations at the State House last week are any guide, developers can expect to see opposition as their plan moves forward. The state will be an arbiter in those disputes, not a cheerleader.

Lawmakers also should ask why they should pay for a study at the same time they are cutting services to some to the state’s neediest people. A $300,000 line item would hardly be noticed in the budget of a project that is expected to cost more than $1 billion.

Last year, Gov. Paul LePage made a point of vetoing several bills because they called for state-funded studies. He should consider staying consistent on that score if this bill gets to his desk.