List of business routes of the Interstate Highway System

From the AARoads Wiki: Read about the road before you go
Jump to navigation Jump to search
Dwight D. Eisenhower National System of Interstate and Defense Highways
System information
FormedJune 29, 1956[1]
Highway names
InterstatesInterstate nn (I-nn)
Business Loop:Business Loop Interstate nn (BL I-nn)
Interstate nn Business Loop (I-nn Bus. or I-nn BL)
Business Spur:Business Spur Interstate nn (BS I-nn)
Interstate nn Business Spur (I-nn Bus. or I-nn BS)
System links

The Interstate Highway System of the United States, in addition to being a network of freeways, also includes a number of Business Routes assigned by the American Association of State Highway and Transportation Officials (AASHTO). These routes connect a central or commercial district of a city or town with an Interstate bypass, and are signed with green shields resembling the Interstate Highway shield. The word BUSINESS is used instead of INTERSTATE, and, above the number, where the state name is sometimes included, the word LOOP or SPUR appears. A business loop has both ends as its "parent", while a business spur has a "dangling end", sometimes running from the end of the Interstate to the downtown area.

As the main purpose of a Business Interstate is to serve a downtown area, it is typically routed on surface roads. Thus Business Interstates do not have to meet Interstate Highway standards and are not considered part of the Interstate Highway System. AASHTO does, however, apply similar standards as to new U.S. Highways, requiring a new Business Interstate to meet certain design standards.[2] Business Interstates are also sometimes routed onto freeways that were once designated as mainline Interstates themselves, such as the now-decommissioned Interstate 40 Business in Winston-Salem, North Carolina, and the existing Interstate 80 Business in Sacramento, California.

Business Interstates are most often posted in the western states, across the Great Plains and in Michigan. Eastern states generally did not designate business routes, as most of the Interstates paralleled the original U.S. Highways instead of directly replacing them. With the exception of mountainous areas, this left most of the U.S. Highways in place, or as co-signed routes with the parent Interstate, while the former routes were redesignated as local or frontage roads. In contrast, construction of the Interstate system in the western states often directly overlaid the old U.S. Highway, leaving the former road impassable or as a disconnected route. Exceptions were at cities and towns, where the freeway would shift onto a bypass around them. This often left extant segments of old U.S. Highways in place, with a business route designation applied to them as a motorist aid to and from a business district of collection of motorists services.

Like auxiliary Interstate Highways, Business Interstates can be repeated from state to state along their route. However, unlike auxiliary Interstate Highways, Business Interstates can also be repeated in several locations within the same state.



Defunct routes are listed in italics.

Interstate 5

Interstate 205

Interstate 8

Interstate 10

Interstate 15

Interstate 17

Interstate 19

Interstate 20

Interstate 24

Interstate 25

Interstate 126

Interstate 526

Interstate 27

Interstate 29

Interstate 229

Interstate 30

Interstate 35

Interstate 40

† Business Loop I-40 for Glenrio, Texas is a spur route (at the New Mexico state line it becomes a country road), but is posted as a business loop.

Interstate 44

Interstate 45

Interstate 49

Interstate 55

Interstate 65

Interstate 69

Interstate 70

Interstate 72

Interstate 75

Interstate 375

Interstate 76 (west)

Interstate 376

Interstate 80

Interstate 83

Interstate 84 (east)

Interstate 84 (west)

Interstate 85

Interstate 385

Interstate 585

Interstate 86 (west)

Interstate 89

Interstate 90

Interstate 94

Interstate 95

Interstate 495

Interstate 96

Interstate 196

Interstate 496

Interstate 696

See also


  1. ^ Weingroff, Richard F. (Summer 1996). "Federal-Aid Highway Act of 1956, Creating the Interstate System". Public Roads. Washington, DC: Federal Highway Administration. 60 (1). Retrieved March 16, 2012.
  2. ^ Special Committee on U.S. Route Numbering (November 15, 1997). "Report of the Special Committee on U.S. Route Numbering to the Standing Committee on Highways" (PDF) (Report). Washington, DC: American Association of State Highway and Transportation Officials. Archived from the original (PDF) on October 16, 2017.
  3. ^ District 11-0 (August 19, 2009). "I-376 Corridor New Exit Numbers" (PDF). Pennsylvania Department of Transportation. Retrieved November 21, 2009.{{cite web}}: CS1 maint: numeric names: authors list (link)[permanent dead link]

External links