Posted May 23, 2008. Revised December 17, 2010 and February 24, 2011.
The Federal Highway Administration (FHWA) receives occasional inquiries related to shared use paths and bicycles on, along, or near Interstate highways or other freeways.
Under the United States Department of Transportation Policy Statement on Bicycle and Pedestrian Accommodation, "The DOT policy is to incorporate safe and convenient walking and bicycling facilities into transportation projects. Every transportation agency, including DOT, has the responsibility to improve conditions and opportunities for walking and bicycling and to integrate walking and bicycling into their transportation systems. Because of the numerous individual and community benefits that walking and bicycling provide - including health, safety, environmental, transportation, and quality of life - transportation agencies are encouraged to go beyond minimum standards to provide safe and convenient facilities for these modes."
Note: The term "Shared Use Path" means a multi-use trail or other path, physically separated from motorized vehicular traffic by an open space or barrier, either within a highway right-of-way or within an independent right-of-way, and usable for transportation purposes. Shared use paths may be used by pedestrians, bicyclists, skaters, equestrians, and other nonmotorized users.
There are no Federal laws or regulations that prohibit shared use paths along or near Interstate highways or other freeways. Bicycle and pedestrian accommodations may be allowed on Interstate and other major highways and freeways. Bridges are essential in any transportation network, and many Interstate or other freeway bridges often are the only possible bridges across rivers, canyons, railroads, other highways, or other major barriers. Major highway bridges often are necessary links for nonmotorized transportation networks.
Bicyclists and pedestrians should be accommodated in new construction in corridors where there is current or potential demand. Under 23 U.S.C. 217(g), transportation plans must consider bicycle and pedestrian accommodations.
23 U.S.C. 217(g) Planning and Design.--
In General.--Bicyclists and pedestrians shall be given due consideration in the comprehensive transportation plans developed by each metropolitan planning organization and State in accordance with sections 134 and 135, respectively. Bicycle transportation facilities and pedestrian walkways shall be considered, where appropriate, in conjunction with all new construction and reconstruction of transportation facilities, except where bicycle and pedestrian use are not permitted.
Safety considerations.--Transportation plans and projects shall provide due consideration for safety and contiguous routes for bicyclists and pedestrians. Safety considerations shall include the installation, where appropriate, and maintenance of audible traffic signals and audible signs at street crossings.
Under 23 U.S.C. 217(e), bridge deck replacement and rehabilitation must consider bicyclists:
23 U.S.C. 217(e) Bridges.--In any case where a highway bridge deck being replaced or rehabilitated with Federal financial participation is located on a highway on which bicycles are permitted to operate at each end of such bridge, and the Secretary determines that the safe accommodation of bicycles can be provided at reasonable cost as part of such replacement or rehabilitation, then such bridge shall be so replaced or rehabilitated as to provide such safe accommodations.
There are several examples of shared use paths along or within Interstate or other freeway rights-of-way. Nearly all have obvious barriers (walls or fences) or grade separation between the freeway and the shared use path.
I-5, Portland, Oregon. There are several locations where there are shared use paths within or adjacent to Interstate rights-of-way in Portland OR, such as the Eastbank Esplanade along the Willamette River, and adjacent to I-5. I-205 in northeast Portland has a separated path for several miles. There are portions of shared use paths along or near other Interstates in Portland. Numerous website links are available through web search engines.
I-66, Arlington Virginia. A shared use path was built adjacent to I-66 as part of the environmental mitigation. There is always a barrier (usually a sound wall, sometimes a fence) between the Interstate lanes and the path. Crossings over or under the Interstate are grade separated. Where the path is adjacent to the Interstate, it usually (but not always) crosses streets with a grade separation. The portion of I-66 adjacent to the Washington & Old Dominion rail-trail has the Metrorail in the median (a rail-with-highway-with-trail), and provides access to the East Falls Church Metro Station. The Martha Custis Trail provides access into Washington DC.
I-70, Glenwood Canyon, Colorado. This is a Best Practice for incorporating various uses along an Interstate highway right-of-way through a canyon. See the March/April 2004 edition of FHWA's Public Roads Magazine.
I-90, Seattle, Washington: There is a shared use path using the I-90 bridge across Lake Washington on the east side of Seattle. See the City of Seattle Bike Maps website.
The League of American Bicyclists has a list of Interstate Bridges with Bicycle Access.
There are photos of shared use paths next to various kinds of highways at www.pedbikeimages.org (the FHWA-supported Pedestrian and Bicycle Information Center). On the Welcome page, click on Design and Engineering. Near the top you will see Bike Trails & Shared Use Paths and Adjacent to Road. You will see many examples, including some examples along Interstate highways.
There are no Federal laws or regulations that prohibit bicycle use on Interstate highways or other freeways. Although a State may prohibit bicycles on freeways, prohibition is not a Federal requirement. Most western States allow bicycles to use Interstate highways or other freeways. Many of these States restrict bicycle use in urban or other congested areas.
In some locations, the Interstate highway or other freeway may be the only reasonable route, or may be preferred compared to other steep, narrow, or winding routes. A State should consider safety and traffic concerns along the freeway and along alternative routes when considering whether or not to allow bicyclists to use freeways.
The Guide for the Development of Bicycle Facilities 1999 from the American Association of State Highway and Transportation Officials (AASHTO) recognizes that bicycles may use freeways (see page 60). To order a copy, go to the AASHTO Bookstore.
Section 166 of title 23 allows motorcycles and bicycles to use High Occupancy Vehicle (HOV) facilities, unless either or both create a safety hazard. If so, the State must certify, the Secretary must accept certification, and it must be published in the Federal Register with opportunity for public comment.
If you need additional information, please contact:
Bicycle and Pedestrian Program Manager
Federal Highway Administration
Trails and Enhancements Program Manager
Federal Highway Administration