"We're on the wrong side of the tracks, and it's freaking me out!"
That message is somewhere on my wife's phone, and it's all due to my first experience with what I've come to learn is called "single-tracking."
I had been riding Valley Metro light rail for years before joining the company, commuting from Veterans Way & College near Sun Devil Stadium to the station at 44th Street & Washington near the airport to get to work. The train operator announced that we'd be rolling on the opposite side of the tracks due to some sort of problem, but there was still a lingering fear that things may be terribly wrong.
Now that I work at Valley Metro, I have a much better perspective on the situation. As a commuter, single-tracking was an extremely rare occurrence. As a Valley Metro employee who works full time in the rail operations control room, I now know that it happens nearly every day, and sometimes, multiple times a day.
There are many reasons why this can happen. Usually, it involves vehicles that have become stuck on a track for some reason. Once there's word of a blockage, the operations staff leap into action! Behind the scenes, staff at the operations control center are like air traffic controllers, only for trains. They know where all the trains are at all times, and are in constant communication with train operators to make sure everything runs smoothly. When there's a problem, they quickly assess the situation and find the best way to get around the obstacle.
The operations staff will determine which switch will be used to get around the blockage, and then order trains to hold, if necessary, to allow the oncoming train to safely use the opposite track. Field supervisors are dispatched to get a first-hand look at the situation, and communications specialists (like me) make announcements at stations to inform passengers that their next train will be arriving on the other track.
Ultimately, my panic over my first experience with single-tracking wasn't necessary. The main priority for Valley Metro operations staff, field supervisors and train operators is safety, and they take that responsibility very seriously. So, don't freak out! You're in good hands, and with the expertise of our team members, you'll get to your destination safe and sound.