Updated 9/18/2014 with MPR article
Fred Melo writes in the Pioneer Press about Always Green Traffic Control “Green Line: Inventor proposes using timing, speed to improve travel time“
“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 Department of Public Works.
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.
Tim Harlow at the Star Tribune writes in his column The Drive: Nick Musachio and the Always Green Traffic Control
David Levinson, a transportation expert at the University of Minnesota, says the Always Green Traffic Control has potential.
“I think it would work best for isolated intersections on rural expressways, but there is no reason it couldn’t work in an urban area,” Levinson said. “Static speed signs have been used for decades on Connecticut Avenue in Washington, D.C. Something dynamic should do even better. I do believe it warrants a field test.”
Musachio faces the challenge of getting somebody to do just that. He’s been bending ears of the St. Paul Public Works Department, but so far they have not bitten.
“In theory the system could work, but it has not been tested in a real environment. Until that happens, we won’t consider it,” said city spokeswoman Kari Spreeman.
Marion Renault at MPR writes “Inventor says synchronized lights could boost Green Line travel time” [I hope by “boost” she means reduce.]
“You can either change the lights to match the vehicles,” said David Levinson, a civil engineering professor at the University of Minnesota. “Or you can change the vehicles to match the lights.”
Levinson said keeping cars moving at a steady speed is optimal for traffic flow. But he said it takes a lot of coordination and a tightly-maintained fixed traffic system to create a grid of alternating, forward-moving platoons of cars and trains.
Though Musachio is certain the system would work “perfectly” with the Green Line, David Levinson, associate professor [sic] in the Department of Civil Engineering [double sic], isn’t so sure.
“The Green Line is all tied up in politics,” he said.
Levinson said the system warrants a field test but believes a rural or suburban traffic signal is the place to start before it moves to an urban area.