HOV Lanes sometimes can be reversable. They are quite weird and only open at certain times. During rush hour in the morning they are open going into the city. During rush hour at night they are open going out of the city. There are gates on either end of the HOV Lane and a few electronic signs that display the status (OPEN/CLOSED/CAUTION) of the HOV Lane. One specifically is I-279 going to Pittsburgh, also known as Parkway North. It is seperated from the other 6 lanes of traffic (3 on each side) by Jersey barriers on either side. Two lanes for the major part of the lane. It isn't a very long lane, but it does help some of the congestion. Also, if you are leaving a Pittsburgh Pirates game or a Steelers game, it is allowed for you to drive in the HOV Lane without the occupancy requirement. This is also true for weekends. The HOV Lane is also used for buses extensively using it.