The Pennsylvania Turnpike Commission's reconstruction project involving seven miles of the toll road between Mileposts 31 and 38 provides ample evidence as to why the state Department of Transportation is focused primarily on maintaining existing roads rather than constructing new ones.

That evidence is the construction cost.

For the seven miles of turnpike in question, for which ground was broken on Thursday, the work will involve an outlay of $113 million.

Actually, the first work tied to the project began about four years ago with the dismantling and reconstruction of four bridges in the project area at a cost of $18.5 million.

The part of the project on which work began Thursday carries a long construction window — to November 2012. Fortunately for motorists, except for some off-peak single-lane traffic restrictions, two lanes of traffic are expected to be maintained in each direction during construction.

Milepost 31 is about three miles east of the Cranberry interchange, and Milepost 38 is a little more than a mile west of the Butler Valley interchange, which empties onto Route 8.

Motorists paying hefty tolls on what often is referred to as the "Granddaddy of Superhighways" expect modern, safe travel when they enter the highway. The project getting under way is another effort at beefing up safety as well as ensuring a smooth ride for the vehicles that traverse its hundreds of miles of pavement.

Toll revenue makes such major financial commitments possible. PennDOT doesn't have the advantage of major toll funding sources.

At Thursday's groundbreaking, Joseph Brimmeier, Turnpike chief executive officer, said, "We're spending well over $1 billion on the Turnpike this year. We spent $1 billion last year, and we're going to spend $1 billion next year."

He said that funding is "more funding than the (federal) stimulus package that was given to Pennsylvania."

Butler County needs more new roads than it ever is likely to obtain. The economic possibilities would be extraordinary if the city and its surrounding area were served by a modern four-lane, limited-access Route 8 between the Turnpike and Interstate 80, a modern Route 68 connecting the city to Cranberry, and a four-lane, limited-access highway to Route 28.

But with the high cost of new construction, including land acquisition, and the financial constraints under which PennDOT continues to work, Butler seems stuck with the limited possibilities that currently exist.

Unfortunately, not only is there not a major shovel-ready project to adequately connect Butler to one of the major routes, including for a complete four-lane highway from the city to Interstate 79, but, actually, the most rudimentary planning has yet to begin — and may never begin.

During the decades of major highway construction in the big metropolitan areas such as Philadelphia and Pittsburgh, smaller cities were assured that their turn for new highways to meet their needs would eventually come.

Unfortunately, those assurances were in many ways hollow.

Those assurances didn't anticipate the spiraling costs, limited funds, and economic and budget pressures that the Keystone State would encounter and be living under today.

Unfortunately, there's no guarantee that new highway construction ever again will take a front seat.

PennDOT can only look at what is happening on the Turnpike and ponder what could be if its financial resources were multiplied.