News of $115-a-barrel oil, and of gas prices headed toward $4 per gallon, ought to tell Minnesotans that the time to start building a modern rail transit system in the Twin Cities was yesterday. That's why it's regrettable that the run-up to construction of that system's spine -- the Central Corridor link between the Twin Cities' twin downtowns -- has hit a pair of speed bumps this spring.

First came Gov. Tim Pawlenty's April 7 veto of the state's $70 million share of start-up funds. Then, on April 11, the University of Minnesota's Board of Regents reaffirmed its support for a route through Dinkytown -- not the Washington Avenue transit mall chosen in February by the Metropolitan Council, the agency charged with building the proposed line.

Neither of these developments necessarily means the shelving of plans to get Central Corridor approved for federal funding in 2009 and operational by 2014. Neither development should -- not when every year's delay adds roughly 5 percent, or $45 million, to the total cost of the project, and demand for non-auto mobility is soaring. Transit ridership was up 10 percent in the 12 months ending in February.

But what happens in the next month is critical, if Central Corridor is to stay on schedule.

It was encouraging that Pawlenty and DFL legislative leaders last week discussed the revival of the vetoed $70 million bonding provision. Pawlenty erred in using this project as a political bargaining chip -- but DFLers erred in giving him that opening, by sending him a supersized bonding bill. Both sides should be chastened, and should aim to rescue this project from the ash bin before the session's May 19 end date.

They should also call for more cooperation between Met Council and University of Minnesota officials. Their dispute over the rail route appears to be intensifying, just when it should be moving toward resolution.

The university says that the Met Council's preference for an auto-free transit mall on Washington Avenue will require major unaccounted-for expenses for traffic mitigation. A clear plan for meeting those expenses should be identified -- one that does not involve students footing the bill.

The university's preliminary analysis says the Dinkytown route would be cheaper to build and, because of the higher speeds that would be possible, a faster ride. It's also much preferred by the adjacent neighborhood associations. It behooves the Met Council to examine that report quickly and, if its findings hold up, make an earnest attempt to accommodate the route change while staying on schedule. But the university must recognize that the cost advantage it touts for the Dinkytown route will vanish if its selection forces a year's delay.

As a matter of legal authority, the university cannot unilaterally stall the Central Corridor project. But as a matter of practical politics, no governor or Met Council chair wants to take a $450 million transit request to Washington without the backing of such an important stakeholder. By the same token, no university leader should want to stand accused of delaying light rail service to the heart of the Twin Cities, or running up its cost. Each side in this dispute says the other isn't listening. Each had better start.