Reason's Ted Balaker finds carpool lanes aren't filled with co-workers sharing a ride:
"When is a carpool really a carpool? An Arizona woman fought her carpool ticket on the grounds that she did have two people in her car–herself and her unborn child. The judge didn't buy it and now Candace Dickinson must pay up: $367 for improper use of a High Occupancy Vehicle lane. Although this case has been resolved, confusion over the purpose of carpool lanes remains... Carpooling doesn't take cars off the road if cars are just being filled up with passengers who wouldn't be driving anyway. It might be convenient for a mom to take her daughter to soccer practice via the carpool lane, but if the child is under the legal driving age, this sort of carpool does not spare the road from an extra car. Consider a husband and wife driving together. As long as they were going to travel together anyway–perhaps they're off to the movies–this carpool doesn't take cars off the road either."
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