U.S. Route 222 and Pennsylvania Route 272 have a brief concurrency in Fulton Township, Lancaster County in a village called Wakefield. After both routes pass through Lancaster city, they meet up again on the U.S. Route 30 freeway north of Lancaster. U.S. 222 then shifts north as a freeway in its own right up toward Reading and Allentown, with PA-272 paralleling it until that route ends at the Berks County line in between Lancaster and Reading. They also parallel each other (several miles apart) in almost the whole stretch between the Maryland state line and Lancaster. Until yesterday when I drove through Lancaster on U.S. 222, I thought 222 and 272 were concurrent beginning in Willow Street, a borough to the south of Lancaster, and then through Lancaster itself.
U.S. Route 40 splits from I-70 east of Hancock, Maryland after being concurrent with I-68 most of I-68's way through Maryland. U.S. 40 then rejoins I-70 in Frederick, 44 miles to the east, at the same exit that I-270 ends. 29 miles after that, to the west of Ellicott City in Howard County, U.S. 40 leaves I-70 for good. I-70 of course ends in a parking lot at the Baltimore city line about 11 miles later. U.S. 40 meanwhile ends up in Atlantic City.
Not a concurrency, but U.S. Route 1 Business in Bel Air, Maryland, which I live right up the road from, crosses paths with mainline U.S. Route 1 in between Bel Air and a crossroads called Hickory; this is where the U.S. Route 1 "Bel Air Bypass" becomes the "Hickory Bypass". North of Hickory, Business U.S. 1 reaches its northern end at mainline U.S. 1. It's only been like that since around late 2000/early 2001, when the Hickory Bypass and a small extension of Maryland Route 23 opened. For the previous 35 or so years before that, there was only the Bel Air Bypass which ended slightly south of the point where U.S. 1 and Business U.S. 1 cross paths today, and the Hickory portion of Business U.S. 1 was part of mainline U.S. 1. Before 1966 or so there was no Bel Air Bypass either, and mainline U.S. 1 passed straight through downtown Bel Air.