The Maine Turnpike Authority is one of the more curious state agencies. The idea behind the MTA dates back to 1941, when, in an unusually forward-thinking moment, the Legislature decreed a limited access toll road from Kittery to Fort Kent.

The latter provision is why residents of far northern Maine believe they were cheated when — after the federal Interstate Highway Act inaugurated major non-toll roads in 1956 — Maine got only enough money to take I-95 to Houlton.

The first section of turnpike, from York to Portland, was finished in 1948. A second section to Augusta, was done by 1956, when interstate system construction took over. Though it’s hard to believe now, when the Augusta extension opened, there was so little traffic MTA had to offer promotions to get thrifty Mainers to drive on it.

To its critics, the MTA is a secretive and unaccountable agency. It is governed by six directors, all appointed by the governor, with the deputy commissioner of the Department of Transportation serving ex-officio. Except when it chooses to play ball, it is completely separate from MDOT, which is what irks critics.

Legislators and citizens used to lambasting MDOT and its commissioner — it’s practically a spectator sport — are curiously hesitant about MTA, which has a chairman who’s amazingly little known. (It’s currently Gerald Conley Sr., a former Senate president from Portland who’s just had MTA’s new building named for him.)

MTA’s reputation for ignoring the public began when it attempted to widen the road to six lanes north of Kittery back in the 1970s with scarcely a public hearing — a move Attorney General Jon Lund put a stop to. MTA suffered a second defeat when voters deauthorized pretty much the same widening project in 1991, but that defeat had as much to do with voter anger over the recent shutdown of state government as with the road. In 1997, voters approved the widening.

So while many think MTA is too powerful, there’s another sense in which it’s not powerful enough. When the turnpike was installing its new barrier toll system, replacing paper tickets, it wanted to build a central toll station in Scarborough, but folded in the face of intense local opposition.

That retreat is the reason for the inequities that remain in the toll system, and why northbound travelers pay a toll if they exit at I-295, but not if they drive a half-mile to the Maine Mall exit.

Now, the action has shifted to York, where the MTA, having given up on Scarborough, has been trying to build a replacement for the poorly situated York toll plaza, now sinking into a swamp.

York’s residents and selectmen have been giving MTA the business. They’ve objected to every plan for relocating the plaza, the least obtrusive requiring the removal of one house. Yes, one.

So intransigent have the York folk become that they hired their own consultants to recommend that MTA install an all-electronic toll system that would not disturb one inch of currently private property.

It’s a lousy idea. Since MTA has no way to require everyone to use EZ Pass transmitters, it would have to bill everyone without them — and 50 percent of turnpike traffic is out-of-state vehicles, with no way for Maine to compel them to pay.

What might really get York’s attention is moving the toll plaza to Kittery — ending its toll-free access to Portsmouth and Boston.

But there’s one idea from the current criticism worth pursuing — ending the separate status of MTA and combining it with MDOT. New Hampshire built its massive turnpike with a unified agency. The benefits of toll revenue are used as the state sees fit.

Over the past 20 years, MTA has been well funded and MDOT poorly funded. A recent report by the Legislature’s accountability office raised the question of whether MTA is meeting its legal obligation to support the state transportation budget.

A better question is why we even need a separate turnpike agency to administer 100 miles of road in an interstate system five times that long, with more than 7,000 miles of other state highways to maintain.

Angus King, the last governor to raise this question, promised to merge MTA with MDOT. He backed off, he said, because MTA can raise money more cheaply. Perhaps. But it’s hard to imagine that lawyers couldn’t create enough firewalls to keep whatever advantage there is.

The Maine Turnpike is undoubtedly an asset. But it should be managed to benefit the entire state, not just part of it.