RICK SNYDER, the Republican governor of Michigan, wants a major tax increase — $1.4 billion a year — to expand and maintain his state’s ailing transportation system. Terry Branstad, the Republican governor of Iowa, is eyeing a gasoline-tax hike for his state’s roads.

But in Virginia, where the gas tax, the major source of state transportation funding, is among the nation’s lowest — less than those in Michigan and Iowa — another Republican governor, Robert F. McDonnell, is standing pat. Too bad he lacks the political courage of his Midwestern counterparts.

The transportation program Mr. McDonnell unveiled as a candidate in 2009 — all 19 single-spaced pages of it, plus two more enumerating a dizzying array of funding sources — promised almost $1.5 billion in new annual funding and $17.5 billion over a decade to “get Virginia moving again.” Measured against those promises, his actions have fallen glaringly short. While the governor has delivered on some promises, there is unlikely to be much in the way of sustained new funding.

Let’s examine the promises and the reality.

The governor, as he promised, has accelerated the sale of some $3 billion in bonds for immediate construction projects, but it was his predecessor, Timothy M. Kaine (D), who won approval for those funds and got them in the pipeline. That money will be spent in a couple of years, while the state’s massive needs will remain.

Mr. McDonnell promised to dedicate funds to transportation when state revenue growth exceeds 3 percent, but now he’s raised that bar to 5 percent. Either way, and even if the legislature approves, it won’t yield anything approaching the $1.5 billion in transportation funds over a decade that he predicted — and may not raise anything at all if growth remains sluggish.

The governor promised, and has proposed, to dedicate 75 percent of any budget surpluses to transportation, saying that would produce $860 million over 10 years. Some of that may eventually materialize, but it’s hardly money in the bank.

The governor said privatizing Virginia’s liquor saleswould bring in $500 million. That number was plucked from the air to begin with; in any event, the legislature has shunned the idea.

The governor promised more than $1 billion in royalties and taxes from offshore drilling. So far there is no offshore drilling, nor any short-term prospect of it, and it’s unclear how much oil and gas might be extracted.

The governor pledged $2 billion over a decade from growth at the Port of Virginia in Hampton Roads. If and when any revenue starts flowing from that source — legislation has been introduced this year — it’s likely to be a fraction of what Mr. McDonnell predicted.

The governor said adding tolls to Virginia’s interstates would yield $500 million over a decade, but his proposal is under attack and may never get off the ground.

The governor said he would shift a portion of the state’s sales tax revenue to transportation from schools, public safety, health and other programs. That hasn’t happened yet, and the prospects for it in the legislature are 50-50 at best.

Many of Mr. McDonnell’s ideas were fanciful, far-fetched or politically iffy to begin with. They were a smokescreen to advance the notion that major, long-term revenue — which the governor acknowledged was needed — could be generated without resorting to new taxes. Now this has been revealed as an illusion, unsurprisingly.

For the sake of ideological purity, and, most likely, his viability as a possible vice presidential candidate, Mr. McDonnell has proposed no new taxes and has embraced no major initiatives that will provide sustained, year-on-year funding to ease the severely overcrowded and massively underfunded transportation network. That’s fine for the ideologues, but what about commuters and other motorists who rely on a roads network that needs $1 billion in new annual revenue?

Finding that revenue would have required bold strides, but Mr. McDonnell has offered only baby steps. Measured against his own promises, his program is a bust. Perhaps a future executive in Richmond, Republican or Democrat, will take his or her cues from the gutsier governors in Michigan and Iowa.