Imagine if an electronic message sign told you how fast to drive to catch the next green light.

Nick Musachio thinks that’s exactly what will solve the Green Line’s tardiness problem. Instead of forcing traffic signals to turn green as the light rail approaches, he wants to speed the train up in segments and slow it down in others. By continuously adjusting train speeds, the light rail would hit green lights set to appear at predictable intervals.

Musachio, an established inventor who lives in the Como Park neighborhood, said his patented “Always Green” technology has garnered the interest of University of Minnesota transportation engineers and others in the field.

There is one major caveat: Outside of high-tech simulations, it has never been field tested.

“It’s a solid concept. It has potential,” said civil engineering professor John Hourdos, the director of the Minnesota Traffic Observatory at the University of Minnesota in Minneapolis. “But it needs to be tested on the road. You cannot just put it on University Avenue everywhere and hope for the best.”

Faced with travel times that sometimes are nearly an hour on what’s presumed to be a 48-minute route, Metro Transit has been pushing the city of St. Paul to give the new light rail greater power to prioritize green lights at University Avenue intersections.

The city has started experimenting at three low-volume crossings — Chatsworth, Grotto and Victoria streets. Of the city’s 46 signalized crossings, 19 are considered low-volume because they’re believed to accommodate fewer than 3,000 cars on a daily basis.

Musachio suggests doing otherwise. Rather than forcing traffic signals to turn green as the light rail approaches, he proposes keeping the lights on a set timing sequence, so the green lights pop up at predictable, regular intervals without variation.

Using “Always Green” technology on board the light rail vehicles, a screen would alert the driver to adjust speed to catch the next green light. If the driver is not going to make a light a few blocks away, it tells him how much he needs to slow down to get the next green light after that, all without stopping.

The idea is that a continuously moving train is better than a train that stops and starts, even if it means slowing down or speeding up within particular route segments.

Musachio believes the overall Green Line trip would be faster, without sacrificing crossing time for pedestrians and vehicles on cross streets. That’s because the amount of time wasted by rail cars that accelerate from a complete standstill to 30 or 40 miles per hour adds up over the course of dozens of traffic lights.

“When you come to a complete stop, people call it the ‘wasted green,'” Musachio said. “The light turns green, and there’s a two-second delay.”

By braking less, the system would save money and energy, and create a more comfortable ride for passengers.

Musachio tested “Always Green” in software simulations at the Minnesota Traffic Observatory. He recently presented his findings to St. Paul City Engineer John Maczko and other higher-ups in city engineering to receive a skeptical reaction. He has yet to garner an audience with officials from Metro Transit.

“Ultimately, the decision whether or not to implement a system such as this along the Green Line would need to be made by Metro Transit’s project team,” said Kari Spreeman, a spokeswoman with the St. Paul Public Works Department.

David Levinson, an engineering professor at the University of Minnesota who specializes in transportation issues, has blogged about “Always Green” on his website, Transportationist.org.

“It’s an interesting idea,” Levinson said. “Even if the total travel time is the same in both cases, it’d be better than going fast and then stopping. You might even save some time. After you stop, you have an acceleration-deceleration loss (in travel time).”

Levinson acknowledged one drawback, however. “It’s never been tested,” he said.

Frederick Melo can be reached at 651-228-2172. Follow him at twitter.com/FrederickMelo.