I-76 Turnpike is free between Route 18 and Cranberry.
Coming from the west: when entering PA turnpike from I-76 Ohio turnpike, PA has a entrance fee of around $7 for a car and more for a truck and trailer.
Coming from the north: I-376 turns into a toll road at New Castle but it possible to take 422 to the next exit at Moravia and take some back roads to route 18. Some of these roads are not well marked. I-376 is a toll road between Route 51 in the south to 422 in the north. When I-376 is a toll road it is plate read (PA sends you a bill in the mail) or EZ Pass only, no manned toll booths.
Coming from the east: I-76 is easy but is a toll road until you get to Cranberry Township. Then I-76 is free between Cranberry and Route 18. If your coming down I-79 from I-80 and want to cut across to the race track through Ellwood City, be aware that route 351 is closed at the Koppel bridge and the detour adds about 10 miles.
Coming from the south: Either I-79 or I-376. I-376 turns into a toll road at route 51 but you can exit there and take secondary roads to route 18. But as usual for western PA secondary roads there can be steep hills and bumps. Right now there is a sinkhole on route 588 going down the long hill and a stop is required.
Getting off of I-376 and going down route 351 (Fairlane Boulevard) to route 18. The interchange there can be confusing and last time I was there a sign was backward. Also Fairlane Boulevard has some shoulder washout damage from recent storms.
Some notes: If your using a GPS device, there is a Cranberry (way up north) and a Cranberry Township in PA. You want Cranberry Township. Its best to look at the Cranberry Township map on the internet beforehand, as there is two methods of getting onto I-76.
Cranberry Township has just about every store, car rental, and restaurant available in the northeast USA. There is a Tesla and a Maserati/Bentley dealership south on route 19 (Perry Highway). Across the road from the host Marriott hotel is the Pittsburgh Penguins training ice rink. North on route 19 there is a mini-golf and a Costco, and an inside children's playground.
If your running up I-376, before you cross the Ohio river, on the left side at Monaca is the Shell cracker plant under construction with the world's largest crane.
PA has the US's second highest gas tax, typically gas is cheaper out of state.
The sign for Pittrace - Pittsburgh International Race Complex, off of route 18 is not overly large. If you find yourself going uphill on a long smooth road, you're going in the right direction.
One of the venues for breakfast on Saturday morning is at Cracker Barrel which is just east of the host hotel Marriott. Right at that main intersection, there is an off ramp road that goes directly to Cracker Barrel. But it is a one way road. When leaving Cracker Barrel proceed on the same road to a T, turn left on Longtree Way and go to a round-about, then the third turn goes up a hill toj stop light on 228. Cracker Barrel has only been there about a year and half and does not yet show up on some maps and GPS devices.