Interstate Business Route Guides
The following Interstates have business loops/spurs or have Business U.S. or State Routes that act as de facto Interstate business connections. Click on the Interstate to view the list of business routes:
The lists show all the Interstate business routes, both alive and dead. In the table, "decommissioned" denotes business routes no longer in service, "active" denotes active business routes, "not a business loop" denotes business routes that have never existed (such as Business U.S. routes that have both endpoints at an Interstate highway), "proposed" indicates the business route may have been proposed at one time (or is still proposed now), and a (?) indicates I am not sure if the business route ever existed or not. For the purposes of these lists, active business loops are considered to have at least one sign along the route - hence why Business Loop I-89 in Lebanon, New Hampshire, is considered active and Business Loop I-65 in Lebanon, Indiana is considered decommissioned.
The following Interstates do not have green-shielded Interstate Business Loops or Spurs. Interstate 64 is the longest route not to have any business loops or spurs.
- Interstate 4
- Interstate 12
- Interstate 16
- Interstate 26
- Interstate 37
- Interstate 39
- Interstate 43
- Interstate 49
- Interstate 59
- Interstate 64
|* - Pennsylvania 60 Business will become Business Loop I-376 once the extension of Interstate 376 is signed.
Purposes of Business Loops
Interstate business connections (loops and spurs) were approved by AASHTO in 1964 as a method to provide access from the Interstate superhighway to the cities and towns bypassed by the freeway. AASHTO made this decision during the height of Interstate highway system construction.
With business connections (loops and spurs), travelers could choose to follow the main Interstate around the populated area or travel through it via the marked business route. Each state would determine if the business connection would be feasible or necessary.
Many states in the East did not designate business loops, as most of the new Interstates paralleled the old U.S. route, and such a route was not necessary. In the western states, in many places the old U.S. route was directly overlaid by the new Interstate highway. Since Interstate highways did not go directly into towns but rather around them, the business loop designation was used to allow travelers to follow the old U.S. route through town.
For more information on the usage of business connections, check out Dan Stober's Utah Business Loops Page. The introduction eloquently states the reasons why so many western states have business loops and why so many eastern states do not.
Gene J. Yao writes that it would be safe to suggest that Business Interstate routes are much more prevalent in the West than in the East. "That's because out West many Interstates overlaid old U.S. roads and bypassed the cities and towns along the way. With the decommissioning of the U.S. highways it was necessary to give the vestigial remainders of the roadway going through towns a route number that identified them with the Interstate (since the Interstate replaced the U.S. highway). In the East, however, many of the old U.S. routes remain. A business route designation would be redundant with the U.S. route designation. Moreover, they might cause some confusion, since most East Coast people aren't aware of the existence of the business route system and may assume that the green business loop shields actually designate the Interstate mainline. Most states [in the northeast] have avoided spending money on designating business routes with some notable exceptions: New Hampshire (Business Loop I-89 in Lebanon), Massachusetts (Business Spur I-495 in Lowell), and Pennsylvania (Business Loop I-83)."
Maintenance of the business route depends upon the state's preference. Some states, like Illinois, Michigan, South Dakota, and Wyoming, treat business loops as full state highways, receiving the same signage standards as "normal" Interstate, U.S., and state highways. Other states, like California, usually transfer responsibility for business loops to the local municipality when the bypass route is completed. Some other states have some business loops under local control and others under state control, including Nevada and Washington.
In California, business routes are specifically designated based on the requirements specified in the following passage from the California Highway Design Manual. The design manual seems to indicate that by definition, a business route is a loop through a city or town rather than a spur:
(4) Business Routes. A Business Route generally is a local street or road in a city or urban area, designated by the same route number as the through Interstate, U.S., or State highway to which it is connected, with the words "Business Route" attached to the identifying route shields. The Business Route designation provides guidance for the traveling public to leave the main highway at one end of a city or urban area, patronize local businesses, and continue on to rejoin the main route at the opposite end of the city or urban area.
The Transportation System Information Program is responsible for approval of Business Route designations. Applications for Business Route designation and signing must be made by written request from the local government agency to the Chief of the Transportation System Information Program. U.S. and Interstate Business Routes require approval by the AASHTO Executive Committee.
For example, when Interstate 5 was completed in Northern California, maintenance of the old U.S. 99W was turned over for maintenance to the counties and cities rather than Caltrans. There are some exceptions to this, such as Business Loop I-80 (U.S. 50 and California 51) in Sacramento. Most segments of old U.S. 99W were handed over to the counties and municipalities. Although there are several business loops on I-5 between Sacramento and Red Bluff -- in Woodland, Arbuckle, Williams, Willows, and Orland -- I challenge anyone to find their way along the business route. The signage is terrible.
As the Interstate Highway System neared completion, business routes became more prevalent. Business loops were commissioned in some areas where the U.S. route still existed as a means to entice travelers to exit and use the services available in that town. However, business connections were always city arterials, meaning the business route had traffic lights, cross streets, and so on. Sometimes the sections closer to the Interstate were multi-lane divided or even access controlled, but a full freeway business connection was very uncommon.
Types of Business Routes
There are five basic types of business connections:
- Business Loops that replace a decommissioned U.S. route. Examples include:
Business Loops that are from Interstates cosigned with a U.S. Route. Examples include:
- The I-5 business loops in northern California, which replaced U.S. 99W through towns such as Woodland, Arbuckle, Williams, Willows, Orland, Red Bluff, and Redding.
- The I-15 business loops in Utah, which replaced U.S. 91 through towns such as St. George, Cedar City, Parowan, Beaver, and Nephi. Notably, most business loops in Utah are cosigned with a different state highway route number.
- The I-55 business loops in Illinois, which replaced U.S. 66 through towns such as Springfield, Bloomington-Normal, and Lincoln.
- The I-94 business loops in North Dakota, which replaced U.S. 10 through towns such as Mandan-Bismark and Fargo.
Business Loops that are from Interstates paralleled by a U.S. Route. Examples include:
- The I-25 business loops in Wyoming, which provide direct access from the Interstate to the original U.S. 87 route through towns such as Cheyenne, Wheatland, Douglas, Casper, and Buffalo.
- The I-70 business loops in Colorado, which provide direct access from the Interstate to the original U.S. 6 alignment in western Colorado (Grand Junction, Rifle, Idaho Springs) and U.S. 40 alignment in eastern Colorado (Denver, Limon).
- The I-86 business loop in Idaho, which provide direct access from the Interstate to the original U.S. 30 alignment through the town of American Falls.
- The I-75 business loops in southern Georgia, which connect to and supplement U.S. 41 through towns such as Tifton and Cordele.
- The I-80 business loops in Nebraska, which connect to and supplement U.S. 30 through towns such as Sidney.
Business Spurs from Interstate into City/Destination. Examples include:
Business Loop Freeways. With the designation of Business Loop I-80 in Sacramento in 1981, the fifth type of business connection was created: the business loop freeway. There are currently three of them: Business Loop I-40 in Winston-Salem, North Carolina, Business Loop I-80 in Sacramento, California, and Business Loop I-85 in Spartanburg, South Carolina. The Business I-495 Spur Freeway into Lowell, Massachusetts, is a decommissioned business spur freeway from Interstate 495 and U.S. 3 into the city.
- Business I-20 Spur from the I-20/95 junction into Florence, South Carolina.
- Business I-44 Spur into Fort Leonard Wood, Missouri.
Interstate Business Loops in California
California has standards that are unlike those of other states. Joe Rouse provided the official policy on business route signing in California from the state Traffic Manual:
The ROUTE ## BUSINESS sign may be used to direct motorists to an established U.S. or State numbered business route or an Interstate business loop from a State highway. The plate should be installed below an advance ground-mounted directional sign. The sign may be placed separately in advance of the business route if it is necessary. A NEXT RIGHT/LEFT message may be used on expressway and conventional highway installations. A NEXT EXIT message may be used on freeways.
The INTERSTATE BUSINESS LOOP sign may be used to advise motorists of an established Interstate business loop. The sign should be installed on the right on the loop. It should not be placed on the Interstate route itself. The ROUTE ## BUSINESS plate should be used for advanced signing on the Interstate route.
The BUSINESS plate, in appropriate color, may be used to indicate an alternate route that branches from a US or State sign route, passes through the business district, and rejoins the route. The plate should be placed above the ROUTE SHIELD sign. The INTERSTATE BUSINESS LOOP sign should be used on an interstate business loop. The ROUTE ## BUSINESS plate should be used for advanced signing on U.S. or State sign routes.
Finally, here is Caltrans' policy on establishing business routes per the Caltrans Traffic Manual - Section 4-04.5:
State business routes and Interstate Loops are established by the District Directors. U. S. business routes require AASHTO approval. Applications may be made by memorandum and shall include a written request for the route from those local agencies within and whose boundaries the route traverses. A sketch, preferably on letter size stationary, showing the highway relocation and the business route or loop, should be included. Submission for AASHTO approval will be made by Headquarters. Continuous business route signing shall be provided through the bypassed area and back to the highway. If a business route is approved prior to relinquishment, G55 Business plates or G31 Interstate Loop shields will be installed by Caltrans. After relinquishment, they will be installed by the local agency involved.
A random collection of Business Loop and Spur routes from across the country.
Page Updated June 9, 2009.