and Interstate-35 was modernized and upgraded as part of the widening to six lanes of Interstate-35 to Norman. It formerly ran through downtown Norman along Classen Boulevard, Porter Avenue then west along Robinson Street to Flood Avenue. The north–south section of the new alignment along 12th Avenue was previously flagged as SH-77H. I-35 and US-77 remain together until the Fort Smith Junction in downtown Oklahoma City, where it transfers onto Interstate 235. At Interstate 44, I-235 ends, but US-77 continues northbound as a freeway, called the Broadway Extension. The Broadway Extension is a major freeway linking the downtown area to Edmond. In Edmond, it heads east to meet I-35, which it joins again until Guthrie, where it splits off. In Guthrie, US-77 meets State Highway 33. It continues northbound to serve as the eastern terminus of State Highway 164 and turns eastward toward Perry. After passing the north end of State Highway 86, it turns back northward and has a half-interchange with the Cimarron Turnpike. It then carries State Highway 15 for . At Tonkawa, it begins a wrong-way concurrency with U.S. Highway 177 and U.S. Highway 60. It splits off to the north to head through Ponca City and Newkirk, before crossing over the Kansas line towards Arkansas City, Kansas. History US-77 has followed Commerce entirely through the Ardmore city limits since 1950 when that thoroughfare was built in its current form as an early bypass along what was then Ardmore's west side to provide a straighter route for through traffic and relieve downtown traffic congestion, replacing the original US-77 route in Ardmore which followed Broadway east from Commerce to "E" Street, north on "E" Street to 12th and west on 12th back to Commerce before proceeding north on Commerce out of the city. Spurs SH-153 State Highway 153 (abbreviated SH-153) is a short state highway in Love County, Oklahoma. At , it is the shortest non-suffixed state highway in Oklahoma. SH-153 connects U.S. Highway 77 in Thackerville, Oklahoma to Interstate 35 at mile marker 5. It has no lettered spur routes. SH-77C State Highway 77C is an unsigned route through Purcell. It heads east on Main Street, then turns north onto Canadian Avenue. That is the road the eastern terminus of the highway is on, which is at US-77/SH-39. SH-77D State Highway 77D is a Y-shaped spur route through the Turner Falls area. The main branch of SH-77D