The fair place to meet is Columbus, OH — the city closest to the midpoint of Indianapolis and Pittsburgh. From the farther side that’s about 3 hr 31 min of driving.
Recommended midpoint
Columbus, OH
From Indianapolis
3 hr 31 min
168 mi to Columbus
From Pittsburgh
3 hr 24 min
162 mi to Columbus
That’s an even split — both sides drive within 7 min of each other. Indianapolis and Pittsburgh are about 329 miles apart.
Indianapolis and Pittsburgh are about 329 miles apart by road. Split the difference and you arrive near Columbus, the city closest to the halfway point between them. That splits the trip almost evenly — about 3 hr 31 min from Indianapolis and 3 hr 24 min from Pittsburgh.
That's a half-day drive from each side, so Columbus suits an overnight or a weekend rather than a quick coffee — long enough to want a reason to stay, short enough to drive.
If Columbus doesn't have what you're after, Cincinnati and Cleveland are also close to the midpoint and worth a look — each keeps the drive reasonably balanced between Indianapolis and Pittsburgh.
Columbus is the capital and most populous city of the U.S. state of Ohio. With a population of 905,748 at the 2020 census, it is the 14th-most populous city in the U.S., second-most populous city in the Midwest, and third-most populous U.S. state capital. Read more →
Indianapolis, colloquially known as Indy, is the capital and most populous city of the U.S. state of Indiana and the county seat of Marion County. Indianapolis is situated in the state's central till plain region along the west fork of the White River. Read more →
Pittsburgh is a city in Allegheny County, Pennsylvania, United States, and its county seat. Read more →
City descriptions adapted from Wikipedia (CC BY-SA); photos via Wikimedia Commons, credited above.
Estimates use straight-line distance and typical road speeds; real drive times vary with route and traffic.