I'm fully aware of that. In Utah, the express lane isn't separated physically, it's a double white line with a
Dotted line area for entering and exiting the lane. It is to the left of the left/passing lane. It is generally illegal to cross the double white line except in certain situations, despite bad/impatient drivers doing it all the time anyway. I think you're confusing the separated HOV lane and the express lane, which is not physically separated from the left/passing lane by barriers or reflector poles.