| State: | OK |
| Type: | SH |
| Route: | 108 |
| Maint: | ODOT |
| Length Mi: | 24.0 |
| Length Round: | 1 |
| Established: | July 11, 1955 |
| Direction A: | South |
| Direction B: | North |
| Terminus A: | south of Ripley |
| Terminus B: | in Lela |
| Previous Type: | SH |
| Previous Route: | 105 |
| Next Type: | SH |
| Next Route: | 109 |
State Highway 108 (abbreviated SH-108) is a minor state highway in Payne, Noble, and Pawnee counties in north-central Oklahoma. It runs for 24.1miles, from SH-33 south of Ripley to U.S. Route 64 (US-64) in Lela. It has no lettered spurs.
SH-108 was added to the state highway system on July 11, 1955. It had the same extent it does today; only slight modifications have been made to its alignment due to the straightening of connecting highways.
SH-108 begins in Payne County approximately halfway between Perkins and Cushing at SH-33. From here, the highway runs north on Ripley Road. About NaN2 into its journey,[1] the road passes through the town of Ripley (pop. 444).[2] North of Ripley, it crosses the Cimarron River. Seven miles (11 km) later, the highway intersects SH-51, and SH-108 turns west along it, forming a one-mile (1.6 km) concurrency.[2] SH-108 then continues north on Rose Road.[1]
Approximately NaN8 north of SH-51, SH-108 enters Glencoe (pop. 583).[2] The highway then crosses the Cimarron Turnpike on a grade separation with no interchange. The highway shifts to the east about one mile (1.6 km) north of Glencoe.[1] Upon exiting Payne County, the highway straddles the Noble–Pawnee County line all the way to its terminus at US-64 in the unincorporated settlement of Lela.[1]
As of 2012, the highest average annual daily traffic (AADT) count along SH-108 was 5,900, measured along the concurrency with SH-51. The highest traffic volume on SH-108 alone was an AADT of 1,900, measured north of SH-51. The lowest AADT measured was 1,500, which occurred both in Glencoe and south of Ripley.[3] No part of SH-108 has been designated as part of the National Highway System.[4]
SH-108 was first designated on July 11, 1955. The highway was mostly gravel at that time; only the portions from the southern terminus to Ripley and the concurrency with SH-51 were paved.[5] In 1960, the section of SH-108 between SH-51 and Glencoe was paved.[6] In 1963, the paved segment extended north of Glencoe, to the highway's northern terminus.[7]
The first change to the highway's alignment occurred on November 1, 1966, when SH-51 was straightened between Stillwater and Yale; SH-108 was realigned to continue to concur with SH-51. Around the same time, the remainder of SH-108 was paved. The final change to SH-108 was made on June 4, 1974, when a straightening of SH-33 resulted in a slight extension of SH-108 to continue to meet the new highway. No changes have been made since.