US 15 and US 340 run concurrently northeast toward Frederick as a four-lane freeway. The two highways have a diamond interchange with Mt. Zion Road and cross over Ballenger Creek. The road has a diamond interchange with Jefferson Technology Parkway (MD 872G). On the southwest side of Frederick, the freeway has a partial interchange with I-70 (Eisenhower Memorial Highway), a folded diamond interchange with MD 180 (Jefferson Pike), and a partial cloverleaf interchange with the Frederick Freeway, which carries US 40 through the interchange. US 340's eastern terminus is within the third interchange, where US 15 exits north onto the Frederick Freeway and Jefferson Street continues east toward downtown Frederick.