Business routes of Interstate 40
Interstate business routes are roads connecting a central or commercial district of a city or town with an Interstate bypass. These roads typically follow along local streets often along a former U.S. Route or state highway that had been replaced by an Interstate. Interstate business route reassurance markers are signed as either loops or spurs using a green shield shaped and numbered like the shield of the parent Interstate highway.
Along Interstate 40, business routes are found in the five westernmost states through which I-40 passes, California, Arizona, New Mexico, Texas, and Oklahoma. The Interstate has no business routes along its passage through Arkansas nor Tennessee, and there once was a business route in North Carolina, but it was decommissioned in 2020.
Some states regard Interstate business routes as fully integrated within their state highway system, while other states consider them to be either local roads to be maintained by county or municipal authorities or a hybrid of state and local control.
Although the public may differentiate between different business routes by the number of the parent route and the location of the route, there is no uniform naming convention. Each state highway department internally uses its own designations to identify segments within its jurisdiction.
From central Oklahoma westward, the business routes often follow the historic alignment of the former U.S. Route 66.
California
Interstate business routes in California are assigned by the California Department of Transportation, but are not maintained by Caltrans unless they overlay other routes of the state highway system. Local authorities may request route assignment from the Caltrans Transportation System Information Program, and all requests require approval of the executive committee of the American Association of State Highway and Transportation Officials.Needles
Interstate 40 Business is a business loop of I-40 through Needles in San Bernardino County that begins at exit 141 of I-40/US 95 northwest of town. The unsigned highway follows Broadway to the southeast to Needles Highway, then eastward through an underpass of I-40 into the town center. At N Street, the loop turns southward into the southern part of town where it reconnects with Broadway. The route then continues southeastward to I-40 exit 144 where it terminates and US 95 continues southward along Broadway. The route largely follows the former route of US 66 through town except where the historic highway's path has since been disrupted by the construction of I-40.;Junction list
Arizona
The business loops within Arizona are maintained by the Arizona Department of Transportation and by municipal authorities. I-40 has five business loops within the state located in Seligman, Ash Fork, Flagstaff, Joseph City, and Holbrook, and a business spur in Winslow. The state formerly had business loops in Kingman and Winslow, as well as a second loop in Flagstaff. ADOT internally identifies each Interstate business route as a State Business Route with the number of the parent Interstate. Individual loops along an Interstate are designated by adding parenthetical numbers that increase eastward and northward. Gaps in numbering represent removal of former routes or potential expansion.Kingman
State Business Route 40 was a former business loop of I-40 at Kingman in Mohave County. The loop began at I-40 exit 48 where US 93 approaches the intersection from the west along Beale Street and joins the Interstate while the loop proceeded eastward along Beale Street. After a short distance, the loop joined Andy Devine Avenue which carried the former US 66. The loop turned northward, returning to I-40 and US 93 at exit 53 where the loop terminated, but the roadway continues forward, carrying SR 66.;Junction list
Seligman
State Business Route 40 is a business loop of I-40 at Seligman in Yavapai County. The loop begins at I-40 exit 121 on the west end of town and proceeds northward, passing over the former SR 66, a local road still signed as a state route that is a former alignment of US 66. The loop then takes a semicircular path near the Seligman Airport, returning to Historic US 66, where the loop turns east through town. At the eastern edge of town, the loop turns south, returning to I-40 at exit 123.;Junction list
Ash Fork
State Business Route 40 is a business loop of I-40 through Ash Fork in Yavapai County. The highway is co-signed with Historic U.S. Route 66 for its entire length. The loop begins at I-40 exit 145 and proceeds to the northeast along the western edge of town. The loop passes through town as a divided route with eastbound traffic following Park Avenue and westbound traffic routed along Lewis Avenue. The roadways combine on the east end of town, and the loop returns south, terminating at I-40 exit 146. The roadway continues south beyond I-40 as SR 89.;Junction list
Williams
State Business Route 40 was a business loop of I-40 through Williams in Coconino County. The loop began at I-40 exit 161 west of Williams and took US 66 into town. In the town center of Williams, the eastbound and westbound lanes of the loop diverged into a oneway pair near 9th Street. The eastbound lans used the appropriately named "Route 66" while the westbound utilized Railroad Avenue. A junction at 2nd Street provided access to I-40 exit 163 and the Grand Canyon Railway station. East of town, the westbound and eastbound lanes of the loop reconverged. The loop curved northeast at Bearizona Wildlife Park before arriving at a junction with I-40 exit 165, the diamond interchange served as the eastern terminus of the loop. The road continued straight ahead as SR 64, which has its western terminus at exit 165. This route was a former section of US 66 and US 89. On August 16, 1990, ownership and maintenance of the business route was handed over to the city of Williams, and the designation was decommissioned.;Junction list
Flagstaff
I-40 has both a current route traversing the city of Flagstaff in Coconino County and a former route previously on the city's eastside.Current route
State Business Route 40 is a business loop of I-40 through Flagstaff in Coconino County. The loop begins at I-40 exit 191 west of Flagstaff and enters the city following the former route of US 66. In central Flagstaff, the loop intersects SR 89A at Milton Road. The loop turns north and follows Milton Road and then turns east along the street known as Route 66 before intersecting US 180 at Humphreys Street. The loop continues to the east side of Flagstaff, where Route 66 diverges carrying the former alignment of SR 40B, before intersecting US 89. From this intersection, the loop turns southward along Country Club Drive until terminating at I-40 exit 201.;Junction list
Former route
State Business Route 40 was a former business loop on the eastside of the city of Flagstaff in Coconino County. The loop began at the combined route of SR 40B and US 180 and followed Santa Fe Avenue eastward, underpassing the current business route. The loop continued along the former US 66, connecting with I-40 and US 180 at exit 204 for Walnut Canyon Road along the city's eastern edge. The loop was decommissioned in 2008 and returned to the city for maintenance.;Junction list
Winslow
Current route
Interstate 40 Business Spur or State Route 40 Spur is a business spur of I-40 located in Navajo County serving the city of Winslow. The spur begins at I-40/US 180 exit 252 and follows Hipkoe Drive south while concurrent with SR 99. At the intersection with 3rd Street, the two highways split; SR 99 heads east, while SR 40S heads west. After crossing over the BNSF railway, the spur continues for, ending just north of the intersection of Cooperstown Road and the county line.BS 40 was originally designated US 66 Spur on June 15, 1970. The route was re-routed onto a new alignment on August 23, 1974. US 66 Spur was redesignated as BL 40 Spur on October 26, 1984, when US 66 and all of its associated suffixed routes in Arizona were decommissioned and redesignated as SR 66 or business routes of I-40, where US 66 wasn't concurrent with I-40.
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