Green Line Accident is Reminder of Commuter Rail Risks

Friday’s MBTA Green Line crash, that injured some 25 people, is a reminder that even after running vehicles on tracks for almost 200 years, it is still not as safe as it should be.

And while most of the problems in the region recently have involved urban trolley and rapid-transit cars, the commuter rail system that serves Franklin is not immune to problems. Annually, the trains strike and kill multiple pedestrians and crashes are not unknown. Indeed, on passenger-mile basis the commuter rail vehicles may be no safer than the Green, Red, Blue, and Orange line vehicles.

In particular, critics say the “push-pull” style of operation (the locomotive pulls the train outbound but pushes it inbound) may be less safe heading inbound. Why? A Harvard professor, John Stilgoe, writing in the Boston Globe in 2005, pointed out that the more lightly-built passenger cars would be the first part of the train to strike an object in a crash when heading inbound, increasing the risk of passenger injury. He also pointed out the problematic nature of the “push” configuration which could force cars ahead of the locomotive off the tracks during sudden acceleration or deceleration.

Stopping times may be increased in push mode, as well. An investigation by the Auckland, New Zealand transit system in the early 2000s found that virtually all instances of trains accidentally overshooting (passing) a station platform occurred while in push mode.

Finally, an incident in Oxnard, California in 2015, had some pointing at push-pull being part of the problem. According to an NBC News report, the transit operator (Metrolink's) use of “push" trains, was faulted by some in the wake of derailment that injured 30.

According to the report, the three lead cars in the five-car train left the tracks and toppled onto their sides. The last car and the locomotive derailed, but remained upright.

NBC quoted, Edward Pfiester, Jr., an attorney who has represented riders in other derailments, "There's absolutely no question push trains are more vulnerable to derailing," he stated.

The biggest factor in favor of push-pull is reduced cost and faster train turnaround times – there is no actual turnaround, the train is just operated in the opposite direction. These factors have continued to make push-pull the rule rather than the exception with MBTA and most other transit operations.