Business routes of Interstate 25

New Mexico

All of the business loops within New Mexico are maintained by the New Mexico Department of Transportation (NMDOT). In New Mexico, Interstate business routes are named independently of their parent Interstate's designation with business loops of Interstate 25 (I-25) numbered between 10–19, those of I-10 between 20–29, and those of I-40 between 30–39. New Mexico business loop numbers ascend eastward and northward with gaps in numbering to allow for future designations. I-25 begins with a business route through Williamsburg and Truth or Consequences before proceeding northward with additional routes serving the towns of Socorro, Belen, Las Vegas, Springer, and Raton. These routes largely conform to the current or former alignment of the unsigned U.S. Route 85 (US 85) through these communities before the construction of I-25. NMDOT has decommissioned US 85 throughout the state and no longer signs the highway along its length as US 85 entirely follows I-25 with the single exception of the business loop in Las Vegas. The American Association of State Highway and Transportation Officials (AASHTO), however, continues to recognize the New Mexico portion of US 85 maintaining continuity with sections in adjacent states.

Williamsburg – Truth or Consequences

Business Loop 11 is a 5.7-mile (9.2 km) business loop serving the cities of Williamsburg and Truth or Consequences in Sierra County. The loop begins at Exit 75 of I-25 in Williamsburg, intersecting State Road 187 (NM 187), traveling northeast on Broadway Street through Truth or Consequences until meeting Main Avenue. Between that point and Date Street, the route follows two one way roads with Broadway carrying northbound traffic and Main conveying traffic to the south. The routes combine and turn north on Date, intersecting the western terminus of NM 51. Turning northwest, the highway intersects NM 181 and terminates at Exit 79 on I-25 on the north side of Truth or Consequences.

Most of the loop, with the exception of its I-25 interchanges, was previously part of US 85 which joined the route from the south at NM 187 and departed to the north along NM 181.

The entire route is in Sierra County.

Socorro

Business Loop 12 is a 2.9-mile (4.7 km) business loop serving the city of Socorro in Socorro County. The loop begins at Exit 147 of I-25 and travels northwest along California Avenue until an intersection with NM 1. The loop turns north as a divided highway as it enters the city. US 60 intersects from the west, and the loop becomes concurrent with US 60 as the pair of highways continue to the north. The loop terminates at Exit 150 on I-25, and US 60 continues along the Interstate as it exits Socorro.

The entire route is in Socorro, Socorro County.

Belen

Business Loop 13 is a 6.6-mile (10.6 km) business loop serving the city of Belen in Valencia County. The loop begins at Exit 190 on I-25 and intersects the northern terminus of NM 116 as the highway travels north along Main Street into the city. The western terminus of NM 309 is met in central Belen. The loop continues north to NM 314 then turns northwest before terminating at Exit 195 on I-25.

The entire route is in Belen, Valencia County.

Las Vegas

Business Loop 15 is a 4.240-mile (6.824 km) business loop serving Las Vegas in San Miguel County. The loop begins at Exit 343 of I-25 and travels northeast intersecting NM 329. The loop continues north passing to the west of the Las Vegas Intermodal Facility served by the Southwest Chief line of Amtrak just south of the intersection with NM 104. Continuing north, the highway passes east of Municipal Park before terminating at NM 250 and I-25 at Exit 347.

Uniquely among the I-25 business routes, the Las Vegas segment remains as the only recognized portion of US 85 within the state that has not relocated to I-25.

The entire route is in Las Vegas, San Miguel County.

Springer

Business Loop 16 is a 3.4-mile (5.5 km) business loop serving the city of Springer in Colfax County. The loop begins at Exit 412 of I-25 and travels northeast along Railroad Avenue. The loop serves as the main north-south road in the town, and intersects Fourth Street which to the west of the loop is NM 21 and to the east is US 56 and US 412. Continuing northwest, the loop intersects NM 468 and then runs closely parallel to the Interstate before merging at Exit 414.

The entire route is in Colfax County.

Raton

Business Loop 17 is a 4.2-mile (6.8 km) business loop that begins at Exit 450 on I-25 south of Raton in Colfax County concurrent with US 64. The two highways intersect NM 555 then pass east of La Mesa Park traveling along Second Street north into the city. Clayton Road takes US 64 off of the loop to the east as the loop continues north crossing over the rail line that serves the Raton Amtrak Station before turning northwest and terminating at Exit 454 on I-25.

The entire route is in Colfax County.

Colorado

All Interstate business routes are maintained by the Colorado Department of Transportation (CDOT). Within Colorado, all highways maintained by the state are classified as state highways including Interstates and U.S. routes which hold the same numerical designations as their nationally established routes. The numerical values of all state highway names are followed by an alphabetic suffix, although this convention is used by the department internally and not reflected in route signage. Hence, the mainline of Interstate 25 throughout the length of the state is classified as State Highway 25A while its two business routes in Aguilar and Walsenburg are internally named State Highway 25B and State Highway 25C respectively. US 85 and US 87 are hidden routes not recognized nor signed by CDOT in southern Colorado. They are, however, established AASHTO routes maintaining continuity with signed portions in other states along their routes. In southern Colorado, the routes primarily follow I-25 including at Aguilar but with deviations such as along the Walsenburg business route. In addition to these, US 160 joins I-25 at Walsenburg and follows concurrently with the Interstate to Trinidad including the portion bypassing Aguilar. Thus in Walsenburg, US 160 crosses the business route in the town center and again at the business route's southern terminus.

Aguilar

State Highway 25B is a business spur of I-25 connecting the town of Aguilar in Las Animas County to the Interstate. The 2.0-mile (3.2 km) route begins at the corner of Main Street and First Street in Aguilar. The spur proceeds for one block north along N. First St. before turning to the northwest along Lynn Rd. away from town. The route turns east along County Road 60 immediately before terminating at I-25 Exit 34.

The entire route is in Las Animas County.

Walsenburg

State Highway 25C is a business loop of I-25 serving the town of Walsenburg in Huerfano County. The route 4.4-mile (7.1 km) begins at I-25 Exit 49 and proceeds to the west along the southern edge of Walsenburg. The route then turns to the northwest along Walsen Avenue. At Seventh Street, US 160 intersects from the west. US 160 runs concurrently with the loop until US 160 turns off to the east along Fifth Street to I-25. The loop then continues northeast along Walsen Ave. leaving town and intersects State Highway 69 (SH 69) before terminating at I-25 Exit 52.

CDOT does not recognize or sign US 85 in the southernmost part of its route within the state, nor does it recognize US 87 anywhere within Colorado as they are redundant with other routes in the state highway system. The highways remain established by AASHTO primarily along I-25 in southern Colorado and along Walsenburg's I-25 business route.

The entire route is in Huerfano County.

Wyoming

All business routes of Interstate 25 are maintained by the Wyoming Department of Transportation (WyDOT). Wyoming has no naming convention for disambiguation between different business routes with all designated simply as I-25 Business along the Interstate. I-25 has seven business routes within the state. Road concurrences are frequent in Wyoming, and the seven business highways often overlay multiple other highways including US 87 Bus. wholly or partly at all seven locations as US 85 largely follows I-25 throughout the state.

Cheyenne

Interstate 25 Business is a business loop serving the city of Cheyenne in Laramie County. The 8.0-mile (12.9 km) highway begins at Exit 7 of I-25 and US 87 and is routed along Wyoming Highway 212 (WYO 212) and is named College Drive. At just over two and a half miles, US 85 is intersected. Here, I-25 Bus. leaves WYO 212 and turns north onto US 85 and will remained paired with it until its end. I-25 Bus. and US 85 enter Cheyenne from the south and intersect I-80 at Exit 362. At this point I-180 begins while US 87 Bus. joins the route from the west. Despite the Interstate designation, the I-180 portion is not a freeway. The I-180 concurrency only lasts for just over one mile as I-180 ends at I-80 Bus. / US 30 along Lincolnway. I-25 Bus. continues north with US 85 and US 87 Bus. now as a one-way couplet through central Cheyenne northbound as Warren Avenue and southbound as Central Avenue. Near the Cheyenne Regional Airport, the one-way streets combine and continue as Central Avenue before intersecting the southern terminus of WYO 219 at Yellowstone Avenue. I-25 Bus. and US 87 Bus. terminate at Exit 12 of I-25 / US 87. Here US 85 joins those routes northbound.

The entire route is in Laramie County.

Chugwater

Interstate 25 Business is a business route serving the Town of Chugwater in southeastern Platte County, Wyoming. The highway begins at exit 54 of I-25/US 87. At this interchange lies the northern terminus of Wyoming Highway 211 and the western terminus of Wyoming Highway 313. Here I-25 Business travels east overlapping Highway 313 into Chugwater. At six-tenths of a mile, the southern terminus of Wyoming Highway 321 is intersected, and will take over as the routing for I-25 Business, as WYO 313 turns east to leave Chugwater. 2.7 miles later, I-25 Business/WYO 321 reach I-25/US 87 at exit 57 were they both end. WYO 321 is signed from the freeway as I-25 Business, and serves as a defacto business route, however I-25 business is not signed anywhere along WYO 321.

Wheatland

Interstate 25 Business is a business route serving the Town of Wheatland in central Platte County, Wyoming. Interstate 25 Business runs concurrent with U.S. Route 87 Business for its entire length. I-25 Business begins at exit 78 of I-25/US 87. Here I-25 Business begins on a short section of Mariposa Parkway but then turns north onto S. Wheatland Highway for a third of a mile. Wyoming Highway 310 and Wyoming Highway 312 are then intersected as the business route turns east along South Street. A half-a mile later, the business route turns north, now onto 9th Street and intersects Wyoming Highway 316 (Antelope Gap Road) shortly after. Further north, the southern terminus of Wyoming Highway 320 is intersected as the business loop becomes S. Swanson Road. At 2.95 miles, I-25 Business meets I-25/US 87 at exit 80 where it ends.

Douglas

Interstate 25 Business is a business loop serving the town of Douglas in southern Converse County. The 5.0-mile (8.0 km) loop runs concurrently with US 20 Bus., US 26 Bus., and US 87 Bus. for its entire length. I-25 Bus. begins at Exit 135 of I-25 / US 20 / US 26/ US 87 southeast of Douglas. The loop follows E. Richards Street into Douglas. At S. Fourth Street, the loop turn north through Douglas. A mile later, the loop turn west onto Center Street, which becomes Yellowstone Highway. Near its end, the northern terminus of WYO 94 and the southern terminus of WYO 59 are intersected at Riverbend Drive. Past that intersection, the business routes rejoin I-25 / US 20/ US 26 / US 87 at Exit 140.

The entire route is in Converse County.

Glenrock

Interstate 25 Business is a business route serving the Town of Glenrock in Converse County, Wyoming. I-25 Business begins at exit 165 of I-25. The business route travels north, concurrent with Wyoming Highway 95, into Glenrock on Deer Creek Road and then S. 4th Street. At approximately 2 miles, I-25 Bus/WYO 95 intersects US 20/US 26/US 87. Here I-25 Bus turns east onto Birch Street to travel with US 20/US 26/US 87 for the remainder of its route. WYO 95 temporarily ends and resumes its routing west of here. I-25 Bus continues east out of Glenrock, intersecting the northern terminus of Wyoming Highway 90 (Boxelder Road), before reaching its eastern end at exit 160 of Interstate 25. US 20/US 26/US 87 join I-25 eastward.

Casper

Interstate 25 Business is a business loop serving the city of Casper in eastern Natrona County and runs entirely concurrent with US 87 Bus.. The 2.2-mile (3.5 km) loop, along with US 20 Bus. and US 26 Bus., begins at Exit 186 of I-25. The westbound exit ramp leads the northbound loop to F Street serving as the Interstate service road and conveying westbound US 20 / US 26 and northbound US 87 from Yellowstone Street. The business routes turn south along Bryan Stock Trail with eastbound US 20 / US 26 and southbound US 87 to Yellowstone St. while the mainline U.S. routes continue west merging with I-25. Meanwhile, the southbound loop has a direct entrance ramp from Yellowstone to the Interstate. Northbound, the loop follows Yellowstone St. southwest until turning west along First Street. WYO 251 intersects the loop from the south along Wolcott Street before the loop turns north along the unsigned WYO 255 at Center Street to return to I-25 / US 20 / US 26 / US 87 at Exit 188A. US 20 Bus. and US 26 Bus. continue west along First St.

The entire route is in Natrona County.

Buffalo

Interstate 25 Business is a business spur serving the city of Buffalo in Johnson County that runs concurrently with US 87 Bus.. The 1.7-mile (2.7 km) spur begins at Exit 298 of I-25 / US 87 south of Buffalo. I-25 Bus intersects WYO 196 a half-mile into its route as it follows Main Street into Buffalo. One mile later, US 16 joins the spur at Fort Street. US 16 has a short half-mile concurrency with the spur until Hart Street where it turns east along I-90 Bus. where I-25 Bus. terminates. I-90 Bus. approaches the intersection from the north along the northern extension of US 87 Bus.

The entire route is in Johnson County.