Dear 100 Hour Board,
When driving in the carpool lane, on the center divider there are periodically small yellow flashing lights. What are those for? What do they represent? I noticed that the lights happen to be when the solid lines break up.
I presume you're referring to the lights on the backs of the HOV signs facing the other direction. If you are, you'll be interested to know that those light up whenever someone passes beneath the sign who has an Express Pass transponder. Their passage signals UDOT to charge them the specified amount for use of the HOV lane as a toll lane, since they are presumably traveling solo. (If they were carpooling, they would simply turn disable the Express Pass so as not to be charged as though they were alone.) The lights are there to aid law enforcement in determining which cars have transponders.
UDOT has a very informative page on their website about the Express Lanes. The information there includes a short video outlining their purpose and use that I recommend watching. Pay particular attention just after the 2-minute mark for more details about the lights in question.
- The Detective