Bicycle Facilities Design Guidance

This section is a summary of BicyclingInfo.Org’s design and engineering page. Please consult the link for more detailed design guidance.

On-street Facilities

Bicyclists can be found on almost every type of roadway, from rural interstates to local streets, and the majority of these roads have no special facilities designated for bicycling. Nonetheless, they are a critical part of the bicycling infrastructure and need to be maintained and operated so that bicyclists can use them safely and comfortably. Drainage grates, railroad tracks, potholes, utility covers, gravel, wet leaves, pavement joints and many other surface irregularities have a profound impact on bicyclists and can quickly cause a fall and serious injury.

Paved Shoulders

The AASHTO Guide for the Development of Bicycle Facilities notes that in rural areas, adding or improving paved shoulders often can be the best way to accommodate bicyclists – and they have the additional attraction of providing a variety of benefits to motorists and other road users as well.

 Critical dimensions

• Less than 4 feet (1.2m): any additional width of paved shoulder is better than none at all, but below 4 feet a shoulder should not be designated or marked as a bicycle facility.
• 4 feet (1.2m): minimum width to accommodate bicycle travel measurement must be of useable width and should not include the gutter pan or any area treated with rumble strips
• 5 feet (1.5m) or more: minimum width recommended from the face of a guardrail, curb or other barrier

Widths should be increased with higher bicycle usage, motor vehicle speeds above 50mph, higher percentage of truck and bus traffic. Further guidance on the appropriate width of shoulders to accommodate bicyclists on roadways in these situations can be found in FHWA's Selecting Roadway Design Treatments to Accommodate Bicyclists.
 
Wide Outside Lanes

In urban areas, paved shoulders are not normally provided on major roads. A wider outside (or curbside) lane allows a motorist to safely pass a cyclist while remaining in the same lane and this can be a significant benefit and improvement for bicyclists, especially more experienced riders. A wider outside lane also helps trucks, buses, and vehicles turning onto the major road from a driveway or wide street.
 

Critical dimensions

• 14 feet (4.2m): recommended width for wide outside lane width must be useable and measurement should be from the edge line or joint of the gutter pan to the lane line.
• 15 feet: (4.5m) preferred where extra space required for maneuvering (e.g. on steep grades) or to keep clear of on-street parking or other obstacles.
• Continuous stretches of lane 15 feet or wider may encourage the undesirable operation of two motor vehicles in one lane. Where this much width is available, consideration should be given to striping bike lanes or shoulders.

Signed Shared Roadways
 
The AASHTO Guide describes signed shared roadways (bike routes) as "those that have been identified by signing as preferred bike routes" and goes on to describe the reasons why routes might be so designated:

• Continuity between bicycle lanes, trails or other bicycle facilities.
• Marking a common route for bicyclists through a high demand corridor.
• Directing cyclists to low volume roads or those with a paved shoulder.
• Directing cyclists to particular destinations (e.g. park, school or commercial district).

In addition, designation indicates that there are particular advantages to using the route rather than an alternative. Signed shared roadways generally do not succeed in diverting bi cyclists away from routes that are more direct, faster, and more convenient even though they may be on quieter streets.

 The AASHTO guide recommends considering a number of factors before signing a route:

• The route provides through and direct travel.
• The route connects discontinuous segments of shared use paths or bike lanes.
• Bicyclists are given greater priority on the signed route than on the alternate route.
• Street parking has been removed or limited to provide more width.
• A smooth surface has been provided.
• Regular street sweeping and maintenance is assured.
• Wider curb lanes are provided compare to parallel roads.
• Shoulders are at least four feet wide.

In all cases, shared use roadway signing should include information on distance, direction and destination, and should not end at a barrier such as a major intersection or narrow bridge.
 
Bike Lanes

Bike lanes are the portion of the roadway which has been designated by striping, signing and pavement marking for the preferential or exclusive use by bicyclists. Bicycle lanes make the movements of both motorists and bicyclists more predictable.

Bicycle-friendly cities such as Madison, Eugene, Davis, Gainesville, and Palo Alto have developed extensive bike lane networks since the 1970s and more recently large cities such as Tucson, Chicago, Houston, Philadelphia, Portland and Seattle have begun to stripe bike lanes on their arterial and collector streets as a way of encouraging bicycle use.

In general, bicycle lanes should always be:

• One-way, carrying bicyclists in the same direction as the adjacent travel lane
• On the right side of the roadway
• Located between the parking lane (if there is one) and the travel lane

Critical Dimensions

Bicycle lane width:

• 4 feet (1.2m): minimum width of bike lane on roadways with no curb and gutter.
• 5 feet (1.5m): minimum width of bike lane when adjacent to parking, from the face of the curb or guardrail.
• 11 feet (3.3m): shared bike lane and parking area, no curb face.
• 12 feet (3.6m): shared bike lane and parking area with a curb face.

Bicycle lane stripe width:

• 6-inch (150mm): solid white line separating bike lane from motor vehicle lane (maybe raised to 8-inches (200mm) for emphasis.
• 4-inch (100mm): optional solid white line separating the bike lane from parking spaces.

 Signs and Markings

Signs denoting bike lanes or the intersection of a shared use path with a roadway may have specific instructions or significance for bicyclists.

All of the roadway signs, markings, and signals you encounter as you travel across the country are governed by the Manual on Uniform Traffic Control Devices (MUTCD), a detailed manual that is managed by the Federal Highway Administration and contains all national design, application, and placement standards for traffic control devices.

The Federal Highway Administration adopted the current edition of the MUTCD in 2000 after extensive revision. Part 9 of the Manual describes signs, signals, and markings for bicycle facilities (including shared use paths) and can be found on-line at http://mutcd.fhwa.dot.gov/HTM/2003/part9/part9-toc.htm.
 
Some of the most critical elements of Part 9 are:

The definitions used in the Manual and the signs and markings are consistent with the 1999:

• AASHTO Guide for the Development of Bicycle Facilities.
• Smaller sign sizes for use on shared use paths (trails).
• The bicycle lane sign no longer includes the diamond symbol.
• The bicycle crossing warning sign may be used in conjunction a "Share the Road" plaque.
• The bicycle crossing warning sign may have a fluorescent yellow-green background color
• All new graphics showing appropriate placement and use of signs and markings.
• Guidance on the appropriate use of Stop and Yield signs at trail/roadway intersections.

Much of the new information in the Manual was developed and recommended by the bicycle technical sub-committee of the National Committee on Uniform Traffic Control Devices (NCUTCD). The NCUTCD advises the Federal Highway Administration on the content of the Manual.

Bicycle Parking

More than 1.5 million bicycles are reported stolen every year in the United States and fear of bicycle theft is recognized as a significant deterrent to bicycle use. The availability of safe and convenient parking is as critical to bicyclists as it is for motorists and yet it is frequently overlooked in the design and operation of shops, offices, schools, and other buildings.
 
Bicycle parking needs to be visible, accessible, easy to use, convenient, and plentiful. Racks need to support the whole bike and enable the user to lock the frame and wheels of the bike with a cable or U-shaped lock. Parking should preferably be covered, well lit, and in plain view without being in the way of pedestrians or motor vehicles. And if any of these criteria aren’t met, there’s a good chance cyclists won’t use what is provided and will park wherever they think their bike will be safe.

The International Bicycle Fund has created a two-page fact sheet on bicycle parking criteria that discusses these many factors in more detail and further advice on planning for bicycle parking can be found related specifically to shopping , or commuting .
 

Finding a Good Location

Having determined which stores, schools or street corners need bike racks, the next task is find the location for the rack so that it is clearly visible and accessible, yet does not interfere with pedestrians or vending machines or whatever else is also on the street corner. For example, the City of Seattle specifies that:

• Racks are installed in public space within the Seattle City limits, usually on a wide sidewalk with five or more feet of clear sidewalk space remaining.
• Racks are placed to avoid conflicts with pedestrians.  They are usually installed near the curb and away from building entrances and crosswalks.
• Racks can be installed in bus stops or loading zones only if they do not interfere with boarding or loading patterns and there are no alternative sites.

The City of Chicago notes that they will provide racks only on sidewalks ten feet wide or more, and they can’t be installed on the city’s heated, vaulted, or architectural sidewalks for a variety of technical reasons. The city will only install bike racks in concrete, as they cannot be securely anchored in asphalt. Racks must be four feet from fire hydrants, curb ramps, building entrances etc.

Choosing the Type of Rack

The City of Denver’s regulations specify that “The Inverted U type bike rack is the required bicycle parking rack”, although other racks may be proposed provided that they meet certain performance requirements. Racks should:  

• Support the frame of the bicycle and not just one wheel.
• Allow the frame and one wheel to be locked to the rack when both wheels are left on the bike.
• Allow the frame and both wheels to be locked to the rack if the front wheel is removed.
• Allow the use of either a cable or U-shaped lock.
• Be securely anchored.
• Be usable by bikes with no kickstand.
• Be usable by bikes with water bottle cages.
• Be usable by a wide variety of sizes and types of bicycle.

Short-Term Bicycle Parking

Most communities divide parking facilities into those that provide acceptable long-term or short-term parking. Short-term bicycle parking is usually defined as being two hours or less, such as might be necessary outside a store, or for visitors to an office building or Government service center. Both Portland and Denver recommend racks be within 50 feet of the main entrance to the building, or entrances that are frequently used by bicyclists. The Palo Alto bicycle parking ordinance actually requires the furthest bicycle parking rack to be no further away from an office entrance than the nearest car parking space! Other critical factors for short-term parking are that it be:

• Well distributed (i.e., it’s likely better to have four or five racks spread out along one city block rather than a group of four or five racks mid-block)
• visible to the cyclist in areas of high pedestrian activity, to discourage would-be thieves

Long-Term Parking

Long term parking usually suggests that the bicyclist is leaving the bike all day, or overnight, or for an even longer duration. Obviously the level of security and protection from the elements needs to be greater, but the immediate convenience of the parking facility may not be as important.

Long-term parking options include:

• Lockers, individual lockers for one or two bicycles.
• Racks in an enclosed, lockable room.
• Racks in an area that is monitored by security cameras or guards (within 100 feet).
• Racks or lockers in an area always visible to employees.

A growing number of communities are supporting the development of centrally-located secure bicycle parking garages that also offer bike rentals and repairs, easy links to transit, showers and lockers, and a variety of other services. There are three Bikestations in California and similar facilities under development in Fort Collins, and Denver, Colorado, Seattle, Pittsburgh and Chicago.

Spacing and Siting Standards

Perfectly good racks that are poorly installed will simply not be well used. Racks that are too close to the wall, or which don’t have enough room between them, will end up sitting empty while nearby railings, trees and light poles continue to be used by bicyclists.

The Denver, Portland, and Madison parking guides all provide detailed information on the precise location details of racks to ensure these problems don’t occur.

Shared Use Paths (Trails)

Shared use paths provide many valuable benefits including transportation links, recreation areas, habitat corridors, economic development attractors and outdoor fitness centers. They may range in length from a mile or two in a downtown, to a regional commuter route of 15 miles or more, right up to a cross-state or interstate path covering hundreds of miles. Regardless of the location, purpose, level of use, or mix of users, there are certain design elements that are important for the successful and safe operation of a shared use pathway.

Important Principles of Shared Use Path Planning and Design
 

1. Shared use paths are an addition, and complimentary, to the roadway network: they are not a substitute for providing access to streets and highways. Even the most extensive trail network cannot provide access to all the origins and destinations in a community, and trail users have to be able to get to and from the trail on the regular street network.
2. Shared use paths function best when they are in their own right of way. Paths along former railroad corridors or canals work well because they are likely to have fewer intersections with roadways, and may even be completely grade separated from crossing roadways. By contrast, paths that have frequent intersections with roadways and/or driveways usually require path users to stop or yield at every crossing and every crossing creates potential conflicts with turning traffic.

National and state design manuals strongly caution against developing shared use paths immediately adjacent to highways and to designating sidewalks as shared use facilities for a number of reasons. The 1999 edition of the AASHTO Guide for the Development of Bicycle Facilities recommends against such facilities in at least three separate places, and provides a list of nine reasons why.  

1. They require one direction of bicycle traffic to ride against motor vehicle traffic, contrary to normal Rules of the Road.
2. When the bicycle path ends, bicyclists going against traffic will tend to continue to travel on the wrong side of the street. Likewise, bicyclists approaching a bicycle path often travel on the wrong side of the street in getting to the path. Wrong-way travel by bicyclists is a major cause of bicycle/automobile accidents and should be discouraged at every opportunity.
3. At intersections, motorists entering or crossing the roadway often will not notice bicyclists coming from their right, as they are not expecting contra-flow vehicles. Even bicyclists coming from the left often go unnoticed, especially when sight distances are poor.
4. When constructed in narrow roadway right of way, the shoulder is often sacrificed, thereby decreasing safety for motorists and bicyclists using the roadway.
5. Many bicyclists will use the roadway instead of the bicycle path because they have found the roadway to be safer, more convenient, or better maintained. Bicyclists using the roadway are often subjected to harassment by motorists who feel that in all cases bicyclists should be on the path instead.
6. Bicyclists using the bicycle path generally are required to stop or yield at all cross streets and driveways, while bicyclists using the roadway usually have priority over cross traffic, because they have the same right of way as motorists.
7. Stopped cross street motor vehicle traffic or vehicles exiting side streets or drive-ways may block the path crossing.
8. Because of the closeness of motor vehicles to opposing bicycle traffic, barriers are often necessary to keep motor vehicles out of bicycle paths and bicyclists out of traffic lanes. These barriers can represent an obstruction to bicycles and motorists, can complicate maintenance of the facility, and can cause other problems as well.
9. Cyclists using the path against the flow of traffic often cannot see the signs posted for traffic using the roadway without stopping and turning around.
10. Shared use paths need to be connected to the transportation system. Trails do not exist in a vaccuum; users need to be able to get to and from the facility on the regular street network and the transition between the two should be safe, obvious and convenient. Similarly, connections between the trail access points and local transit service can encourage trail use and boost bus ridership.

Strategies for achieving this connection include:

1. Signing access to the trail from the roadway network.
2. Signing the trail at cross streets and vice versa, so that trail users know where they are.
3. Motorists recognize that they are crossing a trail.
4. Intersections between shared use paths and roadways are the greatest challenge. Great care has to be taken in managing the operation of trail/roadway intersections to ensure safety, convenience and comfort are balanced. Trail users don't want to have to stop every few hundred yards at every driveway and intersection, especially where crossing traffic volumes are very small.
5. Shared use paths should be designed based on the same engineering principles that are applied to highways. This doesn't mean that trails should always be mini-highways that flatten everything in their path — but it does mean that principles such as providing adequate sight distances and stopping distances cannot be ignored just because these are trails.

Width and Clearance

1. 10 feet or 3 meters is the recommended width for a two-way, shared use path on a separate right of way.
2. 8 feet may be used where bicycle traffic is expected to be low at all times, pedestrian use is only occasional and passing opportunities are provided.
3. 12 feet is recommended where substantial use by bicycles, joggers, skaters, and pedestrians is expected, and where grades are steep.
4. 2 feet of graded area should be maintained adjacent to both sides of the path.
5. 3 feet of clear distance should be maintained between the edge of the trail and trees, poles, walls, fences, guardrails or other lateral obstructions.
6. 8 feet of vertical clearance to obstructions should be maintained, rising to 10 feet in tunnels and where maintenance and emergency vehicles must operate.

Traffic Calming

Well designed and implemented traffic calming measures can have a number of beneficial impacts for bicyclists. The reduced vehicle speeds associated with such projects can reduce both the severity and incidence of motor vehicle/ bicycle crashes and can make bicyclists feel more comfortable in traffic.

In the late 1990's traffic calming became widespread throughout the nation. The Institute of Transportation Engineers and the Federal Highway Administration recently teamed up to develop a detailed state of the practice report on traffic calming that documents the experience of 20 communities with a variety of traffic calming devices. In addition, they collected numerous resources on traffic calming, and developed a training course on the subject.

The Federal Highway Administration inaugurated a new web site dedicated to all the known and/or electronically publicized transportation programs and studies that pertain to traffic calming. Additional FHWA/ITE web sites can be found at FHWA - Traffic Calming and ITE Traffic Calming.