PORTLAND, Ore– TriMet and Portland & Western Railroad are completing final upgrades and testing for a federally-mandated safety system called Positive Train Control (PTC) along the WES Commuter Rail corridor. As part of the project, crews will need to test railroad equipment during overnight hours Friday night, Dec. 7 through Monday morning, Dec. 10. That will require activation of the crossing safety lights, bells and arms at times. On Sunday night, it will also require trains to travel along the tracks and sound their horns at crossings, even in quiet zones. Among the major safety changes is the addition of Positive Train control. It helps guard against human error and prevents collisions. Check trimet.org/alerts Monday morning ahead of leaving for work or school there may be delays.