The fair place to meet is Chicago, IL — the city closest to the midpoint of Boston and Salt Lake City. From the farther side that’s about 26 hr 22 min of driving.
Recommended midpoint
Chicago, IL
From Boston
17 hr 48 min
849 mi to Chicago
From Salt Lake City
26 hr 22 min
1,257 mi to Chicago
Boston has the shorter trip; the split is off by about 8 hr 34 min. The alternatives below can even it out. Boston and Salt Lake City are about 2,094 miles apart.
Boston and Salt Lake City are about 2,094 miles apart by road. Split the difference and you arrive near Chicago, the city closest to the halfway point between them. That puts roughly 17 hr 48 min of driving on the Boston side and 26 hr 22 min on the Salt Lake City side — the fairest single meeting point among the cities near the middle.
Over this distance most people will fly rather than drive the whole way. Chicago still makes a fair, central place for Boston and Salt Lake City to converge, splitting the travel instead of asking one side to cross the country.
If Chicago doesn't have what you're after, Milwaukee and Omaha are also close to the midpoint and worth a look — each keeps the drive reasonably balanced between Boston and Salt Lake City.
Chicago is the most populous city in the U.S. state of Illinois and in the Midwestern United States. Located on the western shore of Lake Michigan, it is the third-most populous city in the United States, with a population of 2.74 million at the 2020 census. Read more →
Boston is the capital and most populous city of the U.S. state of Massachusetts. It serves as a cultural and financial center of New England, a region of the Northeastern United States. Read more →
Salt Lake City, often shortened to Salt Lake or SLC, is the capital and most populous city of the U.S. state of Utah. It is the county seat of Salt Lake County, the most populous county in the state. 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.