Riders on the Green Line deserve faster, more reliable service than the city of St. Paul has so far allowed. Since the line opened on June 14, trains have displayed a pokey indifference at getting from Union Depot in downtown St. Paul to Target Field in downtown Minneapolis in a reasonable time. The 11-mile run takes nearly an hour. In an end-to-end race with a good long-distance runner, a Green Line train would come in second.

The fault lies less with Metro Transit than with a city that has resisted giving trains priority at 38 intersections with stoplights, including 19 low-volume crossings, most of them along University Avenue. That must change. Except for the busiest downtown streets and, perhaps, for Snelling Avenue and Lexington Parkway, trains should stop only at stations. Forcing trains to stop at other intersections wastes an extra 15 minutes per run (by our count) and costs an extra $1 million per year, according to Metro Transit, which has had to add trains in order to keep schedules and bus connections.

Perhaps the greatest cost is customer frustration, especially when trains are forced to stop at a light before gliding to another stop at the station a few feet away. “Riders see one or two cars getting priority over a train with 200 or 300 people. That doesn’t sit too well,” said Metro Transit General Manager Brian Lamb.

These problems should have been ironed out long before the line opened.

“We’re making progress,” St. Paul Mayor Chris Coleman promised the Star Tribune Editorial Board. “It will get more efficient.”

When trains pass over sensors in the tracks, signals are sent for stoplights ahead to change for a certain time span, allowing trains to pass through. But the time span isn’t always long enough, because some trains take too long to load and unload and some must slow down to avoid a stray pedestrian or vehicle. But the biggest barrier is city policy. If trains were allowed a longer priority at stoplights, St. Paul is afraid that neighbors would complain about trains getting special treatment.

“Remember some of the values that went into this project,” Coleman said. He was talking about not sacrificing local sensibilities for the sake of train speed — specifically, not interrupting the normal flow of auto and pedestrian traffic across University Avenue. “It can’t just create a wall,” he said.

But the mayor vastly overstates that problem. Trains running at 10-minute intervals cross a given intersection only 12 times every hour, meaning that they tie up an intersection for just a few minutes every hour. Vehicle and pedestrian traffic still operate almost normally the rest of the time. That’s hardly a wall.

Despite the Green Line’s languid pace, ridership is fairly good, with higher numbers expected when college terms resume next month. Most riders seem to recognize that the line is not designed primarily for downtown-to-downtown service. (Express buses cover the distance in half the time.)

Still, the Green Line’s slower-than-necessary performance threatens the whole system’s reputation as well as its timely operation. It’s good news, then, that St. Paul and Metro Transit began a pilot project Wednesday to give trains full priority at three Frogtown intersections — Chatsworth, Victoria and Grotto. Extending full priority to the entire line can’t come soon enough.