On Tuesday, March 11, regularly scheduled 1 Line train number 12 rolled into service equipped with a brand-new feature designed to improve train visibility and passenger safety along the at-grade portions of Sound Transit’s light rail network.
This is called the wig wag train, and it is designed to pilot a technology that is already employed on Sounder locomotives and cab cars, as well as in select light rail systems nationwide, as part of our continuing efforts to improve passenger, pedestrian, and motorist safety while interacting with trains in the Rainer Valley.
The wig wag train uses a pattern of flashing lights that are tied in with the train’s bell and horn systems that begin flashing when triggered by the operator. The flashing of the lights is designed to combine with the audible warning from the bells and horns to provide enhanced warnings in any areas where there are potential conflicts with a train.
The story behind the name “wig wag” is also excellent – it refers to an old-fashioned railroad crossing indicator light, which was designed to swing back and forth to indicate a grade crossing. That swinging motion was said to be reminiscent of a dog wagging its tail – thus the name wig wag.
Before entering pilot service, the wig wag program went through an extensive series of tests. While the lights themselves are the same as any other Link light rail vehicle (LRV), control and wiring elements needed to be updated and tested to tie together the system of lights, horns, and bells that operators use to keep people safe.
This was followed by a series of live evaluations, where test trains traversed the 1 line with observers on board and following in cars and on platforms to evaluate the lights and passenger reactions to them. The final test, which took place on Monday, featured a full four car train, led in each direction by the two LRVs equipped with wig wag technology, travelling through the Rainer Valley four times.
Sound Transit’s pilot project to test the effectiveness of the wig wag system on LRVs follows in the footsteps of several other light rail operators, including Twin Cities Metro Transit, which found their pilot so successful that they’re retrofitting their entire fleet with the feature. During our pilot phase the wig wag headlights will be evaluated by staff at Sound Transit and King County Metro to determine the path forward for the program.
To learn more about the this and other programs designed to enhance safety in the Ranier Valley and at some locations in Bellevue and Redmond on the 2 Line, explore the At-Grade Crossing Program. You can also sign up here for the At-Grade Crossing mailing list to stay informed about upcoming projects and opportunities to get involved.