Mesa PD said the crash between a light rail train and a garbage truck on Wednesday was caused by the light rail operator running its version of a red light. ABC15 looked into how Valley Metro light rail interacts with stoplights and intersections.
Each car has a driver in the front cab with a control to handle acceleration and braking, continually communicating with the Valley Metro Operations Center in Phoenix.
Each city’s stop lights are programmed to prioritize the light rail. The lights are triggered when the light rail leaves the intersection before it, much like the button a pedestrian may push to try to cross the street.
“When a light rail vehicle is approaching an intersection, we can get that vehicle through if it’s within a window of opportunity,” said Mesa ITS Engineer Micha Henry.
But if the train takes too long or a pedestrian is crossing, the window of opportunity can close.
“If we have conflicting movements at an intersection,” Henry said. “The light rail vehicle would have to abide by the light rail indication.”
The indication is not the red or green light drivers see at a stop light, but instead a vertical or horizontal white bar in the light rail’s path.
“As with all indications at an intersection, it is the responsibility of the operators to abide by it, that includes pedestrians, vehicle drivers and light rail operators,” Henry told ABC15.
In fiscal year 2023, the light rail had 49 collisions around the Valley, per a Valley Metro report. That’s a little less than a collision every week.
Valley Metro declined an offer for an on-camera interview but did issue the following statement: The collision that occurred on Wednesday, Jan. 3, 2024 between a Valley Metro light rail train and a truck at the intersection of Robson and Main Street in Mesa is under a thorough investigation. Any additional information is unavailable at this time.
