Oklahoma State Highway 9

State Highway 9, abbreviated as SH-9, OK-9, or simply Highway 9, is a major east–west highway in the U.S. state of Oklahoma. Spanning across the central part of the state, SH-9 begins at the Texas state line west of Vinson, Oklahoma, and ends at the Arkansas state line near Fort Smith, Arkansas. State Highway 9 is a major highway around the Norman area. At 348.1 mi,  SH-9 is Oklahoma's second-longest state highway (second to State Highway 3).

West of Interstate 35
From the western terminus at State Highway 203 along the Texas border, the highway travels due east for 5 mi and intersects with SH-30 between Madge and Vinson. SH-9 continues east for 23 mi without intersecting another highway until meeting US-283 and SH-34 2 mi north of Mangum. The highway overlaps the other two routes for 4 mi, going north, before splitting off and heading east again through Granite and Lone Wolf. East of Lone Wolf, the highway forms a concurrency with SH-44. Near Hobart, SH-9 overlaps US-183 for 4 mi(again going northward) before splitting off again.

Continuing east, SH-9 passes through Gotebo, Mountain View, and Carnegie. Around Fort Cobb, Oklahoma, the highway begins 9 mi of travel to the south. There, the route links up with the concurrent U.S. Highways 62 and 281. While US-281 will split off in Anadarko, SH-9 and US-62 remain concurrent until Newcastle. In Chickasha, US-277 joins to form another three-route concurrency with US-62 and SH-9. On the eastern edge of Chickasha, US-62/277/SH-9 have an interchange with I-44, or more commonly known as the H.E. Bailey Turnpike.

Traveling northeast from Chickasha, US-62/277/SH-9 are routed to the town of Blanchard. Four miles later, SH-9 splits away from the two U.S. routes at a diamond interchange that also serves as the eastern terminus of the H.E. Bailey Turnpike Spur. SH-9 remains without any concurrent routes until Goldsby. The section of road east of US-62/277, recently upgraded to a four-lane divided highway, provides a link from the H.E. Bailey Turnpike Spur to Interstate 35. At the interstate, SH-9 merges onto I-35 northbound to cross the Canadian River into Norman.

East of Interstate 35
Through Norman, Highway 9 serves as a major artery providing access to the University of Oklahoma campus (in particular, the Lloyd Noble Center). Around the area, the route is a four-lane divided expressway (with surface crossings and stoplights). However, after a full interchange with 72nd Avenue SE, the road becomes a two lane highway again.

SH-9 continues eastward, passing Lake Thunderbird State Park, before reaching the towns of Tecumseh and Seminole. The road intersects the Indian Nation Turnpike near Hanna, and US-69 near Eufaula. SH-9 provides access to the south side of Lake Eufaula before reaching Stigler.

SH-9 overlaps US-59 for 5 mi, after which the road becomes concurrent with US-271. Both remain concurrent, until the highway ends at the Arkansas border. After passing the Arkansas state line, State Highway 9 becomes I-540, and US-271 continues over the state line concurrent with the Interstate.

History
Officially designated on August 24, 1924, the original route encompassed all of current SH-9 west of Blanchard. East of Blanchard, SH-9 followed a more northerly route. Bypassing Norman, SH-9 ran north to Oklahoma City before going east through Harrah, Meeker, Prague, Henryetta, and Checotah. The highway ended at the original SH-3 in Spiro. Upon the creation of the United States Numbered Routes system in 1926, the section between Oklahoma City and Warner was overlaid with US-266. Four years later in 1930, SH-9 was truncated to Chickasha. By this time, much of the route had become part of US-62.

On 1935-08-27, the route was extended eastward, taking over the original SH-37. SH-9's eastern terminus became SH-48 near Seminole. On 1937-08-25, the route was brought further east to end at US-69 in Eufaula. Part of the newly commissioned section was rescinded on 1937-10-19, when a small segment just east of SH-48 and the entire Hughes County portion were dropped from the highway. These sections were re-added on 1938-09-27.

SH-9 was extended eastward twice in the route's history. The first extension occurred on 1941-02-26, and extended SH-9 to SH-2 at Whitefield. The final extension brought SH-9 to the Arkansas state line on 1941-11-12. The only major realignment in SH-9's history since 1941 was the Norman expressway bypass, which was designated as SH-9 on 1971-11-08.

After the I-40 bridge disaster, parts of SH-9 in eastern Oklahoma served as an emergency detour for eastbound I-40 traffic. All eastbound traffic was routed along the section of SH-9 between SH-2 in Whitefield and US-59. In addition, the section of SH-9 between US-59 and the Arkansas state line were used for eastbound traffic for commercial trucks.

Discussions to widen SH-9 to four lanes east of US-77 in Norman began in 2008. The City of Norman and ODOT have conflict in their proposals for the design of the widened highway. ODOT has proposed a 16 ft paved median, with 12 ft shoulders to accommodate bicyclists. Norman's proposal includes a grass median and a separate bike path along the north side of the right-of-way, running from 24th Avenue S.E. to Lake Thunderbird. ODOT criticized the city's plan as too expensive. The city then proposed, with a narrower raised concrete median and separate bike path. By 2014, the plan for the widening had been finalized and work had begun from US 77 eastward. As of 2024, SH-9 has been widened to four lanes to 108th Avenue S.E. Future plans call for the highway to be widened to four lanes from Pecan Creek to SH-102.

The I-35 and SH-9 West interchange in Goldsby is also expected to be reconfigured into a Diverging diamond interchange. The new design is expected to "accommodate large volumes of turning traffic by shifting traffic to the left side of a divided roadway through a series of coordinated signals for safer and more efficient left turns." This follows a large project that reconfigured the I-35 exits at West Lindsey Street into Single Point Urban Interchange and the SH-9 east exit to a trumpet interchange in Norman. That project started in March 2015 and was completed and opened in October 2017.

Future
The I-35 and SH-9 West interchange in Goldsby is also expected to be reconfigured into a Diverging diamond interchange. The new design is expected to "accommodate large volumes of turning traffic by shifting traffic to the left side of a divided roadway through a series of coordinated signals for safer and more efficient left turns."

Spurs
State Highway 9 creates three spur highways throughout the state. Additionally, it has two business routes, serving towns the main route bypasses. These routes are:
 * Business SH-9, a three-mile (5 km) loop through Hobart.
 * Another instance of Business SH-9 that loops through Gotebo. (This is not shown on the state highway map.)
 * SH-9A is a designation for three distinct highways:
 * A highway that intersects SH-9 in Earlsboro and links the parent highway to I-40 and SH-39 in Konawa. The spur also passes through the town of Maud.
 * A connector highway from US-69 to SH-9 south of Eufaula.
 * A spur route to SH-112 in Arkoma. This section is a former alignment of U.S. Highway 271.