I got to thinking about that last point and went to Google Maps. I couldn't make a link work to what I found, but you can see it if you go to Google Maps and type Cornplanter and Winfield Road Cabot PA.
There is a short and direct access to the north to Rt 422, which connects directly to I-79 North to Erie or I-79 South to West Virginia. You can also continue and access the Pa and Ohio turnpikes. There is also a direct route south to Rt 28, which has an exit that is 2 miles away from the the Allegheny Valley exit on the PA turnpike (I-76) , from which point a van could go west or east. No EZ Pass or cameras to see the van in those days. You could also go east on 422 and through the mountains up into the Allegheny National Forest and into southern New York, where there are several ski areas. That would take about 3 hours but much of it is very rural and soon enough it would have been getting dark and people would be home and inside. Ski areas to the north, the east (Seven Springs) and the south.
Weirdly, this intersection is almost a perfect spot from which to kidnap a child; if you are pretty sure you can get an hour's jump, you can be in Ohio or the PA mountains or halfway to Erie before anyone starts to look. Even in the Amber alert era, chances are several hours would have passed before law enforcement was called and had a chance to interview the kids on the bus and learn about the van with the ski scene. By that time, the van could have been in New York, Ohio, West Virginia, or Maryland--and into ski country in all of those states accept Ohio. In fact, Canada would have been less than four hours away via Buffalo--422 to I 79 to Erie and then straight north to Buffalo.
You can best see what I mean if you put the little focus thingy halfway down in order to see the intersection in relation to other WPA road. I've lived here all my life and always thought of Cabot as so rural, and such a weird spot for a kidnapping. But I'm sure the state troopers that handled the case thought about this location long ago.