US 340 and US 15 cross over Ballenger Creek before reaching a diamond interchange with Jefferson Technology Parkway, which is unsigned MD 872G. The highway's partial interchange with I-70 (Eisenhower Memorial Highway) features ramps from eastbound I-70 to both directions of US 340, a ramp from westbound I-70 to westbound US 340, and a ramp from eastbound US 340 to eastbound I-70 and access to southbound I-270 just to the east. Immediately to the northeast, US 340 and US 15 have a four-loop-ramp interchange with MD 180, which heads west as Jefferson Pike and south briefly as Ballenger Creek Pike. US 340 reaches its eastern terminus at the third interchange, which is a partial cloverleaf interchange with the Frederick Freeway. The first ramp from eastbound US 340 provides access to westbound I-70; the second ramp leads to the northbound Frederick Freeway (US 40), onto which US 15 exits. The ramps from westbound US 340 provide full access to I-70, I-270, US 15, and US 40. The roadway continues northeast as Jefferson Street, which reduces to a two-lane undivided street that heads toward an intersection with MD 144 (South Street eastbound and Patrick Street westbound) just west of downtown Frederick. The portion of Jefferson Street between the overpass of US 40 and just west of Jefferson Street's intersection with Pearl Street is unsigned US 15B.