A proposed six-mile highway outside Charlottesville is so wasteful and ill-conceived that it’s achieved literary status. It prompted best-selling novelist and area resident John Grisham to write a book implicitly denouncing it.

“The Activist,” published last month and aimed at youths ages 10 to 12, is fictional. But Grisham said it was inspired by the decades-long battle over a $245 million bypass west of the city that’s home to the University of Virginia.

Grisham, famed for such legal thrillers as “The Firm,” said the new book is about “a boneheaded bypass around a lovely little college town and all the issues that go into such a boondoggle.”

The rest of the state, and especially Northern Virginia, should be equally appalled. The road is one of the most egregious examples of a pattern in which Gov. Bob McDonnell’s administration relentlessly pushes a major highway project despite abundant evidence that the money could be spent more wisely elsewhere.

Another example, which I described in a January column, is the $1.4 billion “Road for Nobody” outside Hampton Roads. A third questionable project — though more defensible than the first two — is the Bi-County Parkway linking Prince William and Loudoun counties.

“In each of these cases, there are legitimate transportation issues. But there are other answers that are not nearly as costly or destructive,” said Trip Pollard, a land-use specialist in Richmond for the Southern Environmental Law Center.

McDonnell (R) and his hard-charging transportation secretary, Sean Connaughton, are trying to lock in all these highways before their terms expire early next year. Taxpayers ought to demand they first prove the roads are cost-effective.

Voters also ought to insist that gubernatorial candidates Ken Cuccinelli (R) and Terry McAuliffe (D) make clear whether and how they’d change priorities, if elected.

The Charlottesville project, designed to bypass congestion on Route 29 in northern Albemarle County, should certainly be rethought.

For years, it was pitched as a way to speed up travel between southern Virginia and the Washington area. But the state’s own estimate is that the time saved would be only four to seven minutes. That’s not much on the four-hour trip between Danville and Gainesville.

Now the state’s official position is that the bypass — by carrying all the through traffic — would relieve local congestion and improve safety near Charlottesville.

But that’s questionable, at best, because the through traffic is a small fraction of the total.

“The data demonstrate that the proposed bypass does very little to improve traffic operations on Route 29,” said a study in October by the Vermont firm Smart Mobility.

Given all that, it’s a bit of a mystery why McDonnell and Connaughton are so keen to build it.

One theory is that pro-GOP business interests in south-central Virginia have convinced themselves that a bypass is crucial to their future economic health despite the small travel time savings.

“This has become a kind of testosterone thing between the Lynchburg and Danville communities and Charlottesville,” said James Rich, a former member of the Commonwealth Transportation Board.

Another hypothesis is that even though cheaper options exist, they are opposed by influential local business interests. In particular, a pair of overpasses to eliminate major choke points on Route 29 are opposed by an auto dealer and other property owners who would be displaced.

Pollard thinks the administration just has a big-project mentality when it comes to roads.

“It’s a very odd thing for a conservative administration to be in love with large-scale governmental projects,” he said.

One conservative who doesn’t share that view is Rich, perhaps the road’s most credible critic. As a retired attorney for Shell Oil and a former member of the Virginia GOP’s executive committee, he is no knee-jerk highway opponent.

McDonnell appointed Rich to the transportation board in 2010 but pushed him out in December after he vocally opposed the Charlottesville bypass and other projects.

“To me, it’s just immoral to take money from taxpayers and throw it down a rathole for special interests,” Rich said. He finds it especially galling because he knows firsthand how the money could be better spent.

“I was a commuter from Fauquier County to downtown Washington for 20 years. There are needs out there,” he said.

McDonnell and Connaughton deserve credit for procuring this year’s historic, bipartisan transportation funding package. It will add more than $1 billion a year for roads and transit.

For sanity’s sake, however, we shouldn’t let them decide on their own how to spend it.

For previous Robert McCartney columns, go to washingtonpost.com/mccartney.