Speeding Up the Green Line

greenlinerankings1The Green Line’s on-time performance is poor. Few trains are able to meet the already relaxed running time. Lateness of 5 minutes is typical and 12 minutes not uncommon. After almost a month of late and erratically timed trains, it’s clear that unnecessarily restrictive traffic signals in St. Paul are the culprit. In contrast, Minneapolis is doing a pretty good job, with few delays because of their signals.

On top of the lateness, the slow running time is blowing a hole in Metro Transit’s budget, because more trains are required to keep the line from melting down due to the delays. We’re talking millions of additional dollars. The problem is the lack of full signal preemption at the low volume cross streets. There are simply too many traffic lights spaced too close together for conventional signal timing with priority to move the trains along.

St. Paul decided not to do full signal preemption because they didn’t want to unduly delay auto traffic crossing University Avenue. That concern is legitimate for the major streets—Rice, Marion, Dale, Lexington, Hamline, Snelling, Fairview and Vandalia. MnDOT’s online traffic volumes map shows that these have traffic volumes equal or greater than University.

However, there are 19 additional intersections where University has anywhere from 2 to 7 times the traffic of the cross street (see the table)University traffic volumes. Add the LRT riders and that difference increases to 3 to 8 times greater. Several of these cross streets have such low volumes that MnDOT and the City don’t even bother to do traffic counts, meaning they’re under 3000 cars per day.

At a lot of these intersections, a train with 200 passengers sits waiting for a handful of cars on the cross street to clear the intersection. The goal of not delaying autos has produced a perverse effect-more cars are delayed on University than on the cross streets-and it’s clearly hurting the Green Line at the same time.

So convert those low volume intersections to full preemption. That will greatly improve the Green Line’s on-time performance and reduce its operating expense.

Aaron Isaacs

About Aaron Isaacs

Aaron retired in 2006 after 33 years as a planner and manager for Metro Transit, where he worked in route and schedule planning, operations, maintenance, transit facilities, light rail and traffic advantages for buses. He's an historian of transit, as a 40+ year volunteer with the Minnesota Streetcar Museum. He's co-author of Twin Cities by Trolley, The Streetcar Era in Minneapolis and St. Paul, and author of Twin Ports by Trolley on Duluth-Superior.