I think I am reading this as a Park and Pedal inquiry...where to take the bike via car, and ride in the last few miles?
Two suggestions come to mind: Shoot over Rochester to Millvale, and park at Millvale Riverfront Park, and take the trail to the 31st Street Bridge. Then through the Strip a few blocks to his destination.
The other would be to take Union Avenue to Bellevue, park on the street there, and take the Brighton Heights Route along Lincoln/Benton/Brighton/Shadeland/Woodland/Brighton/North Shore/Trail to 31st Street Bridge.
Or, he could even do the Lincoln/Benton/Brighton/Woods Run to SCI-Pittsburgh and take the trail all the way to 31st Street Bridge.
There is no good parking that I know of at the North End of the North Shore Trail (near the Penitentiary) or along Woods Run. But, I don't know the area all that well, and options may exist. That would avoid the McClure hill on the way home. I'd have him explore that area for parking options if he wants a trail ride that is longer than just Millvale to the Strip.