Just based on the map alone it looks like they may have missed the on ramp and may have stopped to turn around. But I'm on the other coast, so I wouldn't know the first thing about driving it in person.
Knowing they went by way of Lake Wolford Road in order to get to Deer Springs, while there are many options in some spots, ultimately, unless there are a lot of missing or unreported pings, they basically HAD to end up on either N. Centre City Parkway or Jesmond Dene to merge onto N. Centre City Parkway.
Otherwise, they can't have gotten to near the Deer Springs ramp unless pings somewhere else were WAY off.
Without knowing some of the middle pings there is some leeway, but knowing the ones they included (how they left the casino, where their initial turns were, etc. onto Lake Wolford - and the last one at Deer Springs) does eliminate some choices.
Had they missed turning left (west) from N. Centre City Parkway and
onto Deer Springs (where if they had gone back east it turns into Mountain Meadow) just in order to take the NB 15, then they'd have continued on N. Centre City Parkway.
N. Centre City Parkway turns into Champagne Blvd after you pass the Deer Springs Rd option, and goes past the Lawrence Welk Resort, and then turns into Old Highway 395 right near Old Castle Road (which is the other route to Valley View from the 15) and you hit Gopher Canyon - the NEXT entrance/exit to the 15 if you miss Deer Springs.
N. Centre City isn't a big road - one lane each direction north of Deer Springs and up to Gopher Canyon, etc.
Had they decided to turn around if they missed Deer Springs, it'd be hard to do without turning into a private drive or something, plus it's pretty clear that road keeps going (if you're driving on it it's pretty clear) and you can tell you're running parallel to the 15 and will eventually hit it again.
Because there are so few options off that road, it seems like if they had turned around to go back, deciding not to trust the parallel / business freeway type route that N. Centre City is, they really shouldn't have been able to miss Deer Springs a second time to then go on the freeway the right way.
Maybe I'll see if I can get up there with someone and drive it so you guys can see it
