State of play: High temps can cause outdoor rails to expand or contort, and trains run at slower speeds for safety.
Zoom in: Metro workers take "heat rides" to monitor track temps — at 135 degrees, all above-ground rail is slowed to 35 mph, about half the max speed.
Meanwhile, Amtrak is experiencing delays in the Northeast Corridor as trains run under heat restrictions — typically 50-70 mph slower than max.
The bottom line: You may want to park it like it's hot until temps cool.
