US 19 Truck Wrong-Way Self Concurrency

[theroadwayone]

So near Pittsburgh, when US 19 Truck reaches I-376/US 222/whatever, it apparently forms a wrong-way concurrency where the northbound and southbound lanes run together. What was the whole rhyme or reason behind that?
(Move this to Northeast if need be.)

[rickmastfan67]

It's because of the lack of space for a complete interchange with PA-51 due to the Fort Pitt Tunnel.