Chapter Three: Designing Local Bicycle and Pedestrian Networks

Bicycle and pedestrian networks are made up of a variety of facility types. Sidewalks, trails, paths, and various kinds of bikeways contribute to the basic infrastructure that accommodates bicycling and walking. Existing roadway rights-of-way serve as the primary way for non-motorized as well as motorized traffic. Trail opportunities complement roadways to complete the non-motorized network.

Following is a discussion of and guidance for design considerations for various bicycle and pedestrian accommodations within the transportation system. In addition to the linear components of a non-motorized network, traffic control, intersection design, and auxiliary facilities such as bicycle parking are covered.

Well-designed bicycle and pedestrian facilities are those that are safe, attractive, convenient and easy to use. They minimize user conflicts, and promote proper use.

Poorly designed facilities are those that are used very little, or used in an inappropriate manner. Poor design is unsafe and can create maintenance difficulties.

Good planning sets the stage for good design. Since most bicycling and a great deal of walking is on or adjacent to streets, the best accommodations result from including bicycle and pedestrian needs at the inception of transportation projects. When added as an afterthought, bicycle and pedestrian facilities will likely be under-designed and costly.

Planning and design resource documents are listed in Appendix One. Of these, several are of primary importance to the local design of pedestrian and bicycle facilities. These include:

Manual on Uniform Traffic Control Devices (MUTCD). This manual contains unified national standards for signs, signals, markings, and devices on all streets and highways open to public travel. “Part IX: Traffic Controls for Bicycle Facilities” establishes national recommendations for signing and marking both on-road and off-road bicycle facilities. A completely rewritten Part IX will be included in an upcoming new edition of the MUTCD. Proposed changes to Part IX include:

• Bringing the new AASHTO bicycle facilities guide and MUTCD into conformity
• New bike lane signs and markings
• New “Share the Road” signs
• New loop detector markings for bicyclists
• Variable-size signs for use on shared-use paths

The MUTCD is available from the U.S. Government Printing Office, Superintendent of Documents, P.O. Box 371954, Pittsburgh, PA 1 5250-7954, (202) 783-3238. FAX orders: (202) 512-2250.

Guide for the Development of Bicycle Facilities, 1999. American Association of State Highway and Transportation Officials (AASHTO). These national guidelines and minimum design criteria have been published by AASHTO to provide information on the development of new facilities to enhance and encourage safe bicycle travel. Most state transportation departments use the AASHTO Guide as the standard for bicycle facility development. The Guide is available from AASHTO, 444 N. Capitol Street NW, Suite 249, Washington, DC 20001, (202) 624-5800.

Selecting Roadway Design Treatments to Accommodate Bicycles. This manual was published by FHWA in 1994 to assist transportation planners and engineers in selecting roadway design treatments to accommodate bicycles. It offers guidelines on the desirable width for various types of design treatments based on the anticipated type of bicycle users and various combinations of traffic operational factors. Document #FHWA-RD-92-073 is available at no cost from the FHWA Reports Center, (301) 577-0818. FAX orders: (301) 577-1421.

Design and Safety of Pedestrian Facilities: A Recommended Practice, 1998. Institute of Transportation Engineers (ITE). This is a compilation of articles by experts on the design of pedestrian facilities. Articles address many aspects of roadway, walkway and crosswalk design, as well as, grade separation, signing and signalization. It is available from ITE, 525 School St., S.W., Suite 410, Washington, DC 20024-2797. (202) 554-8050. FAX orders: (202) 863-5486.

AASHTO is in the process of developing a Guide For the Development of Pedestrian Facilities. It will be similar in scope to the AASHTO bicycle guide and will provide planning and design guidance. It will be available in early 2002. (See above for contacting AASHTO).

Accessible Rights-of-Way: A Design Manual, 2000. U.S. Architectural and Transportation Barriers Compliance Board (Access Board). This recently published manual addresses the legal and design aspects of accommodating disabled individuals within the street environment. Available from The Access Board, (800) 872-2253

http://www.access-board.gov

FHWA is in the process of preparing a two-part report. Designing Sidewalks and Trails for Access: Part I: Review of Existing Guidelines and Practices, is complete; Part II: Best Practice Design Guide, is under review. To request a copy of the draft documents call (202) 366-7660 or (202) 366-3409. This report addresses the needs of a variety of vulnerable groups, including the elderly, the disabled and children. Design details are offered for sidewalks and trails that are meant to assure the accommodation of the widest possible range of users for each type of facility.

Ideally, every community should be connected to a significant trail. If a community is served by nearby trails, the benefits can be increased by improved access. Access is improved by:

• Local bicycle and pedestrian facilities
• Signing
• Amenities

Local Facilities

Local bicycle and pedestrian facilities allow and encourage bicycling and walking in a community. These facilities should complement and connect to state and regional trails. Design guidance for trails and multi-use paths is summarized in Chapter Four of Iowa Trails 2000. Design considerations for bicycle and pedestrian facilities within the transportation system are discussed below.

Signing

There are four basic types of signs that offer information about the bicycle and pedestrian environment:

• Directional signs give street names, trail names, direction arrows, and other navigational information.
• Cautionary signs warn of upcoming roadway crossings, steep grades, blind curves, and other potential hazards.
• Regulatory signs tell the “rules of the road” prohibiting certain uses or controlling direction of travel.
• Interpretive signs offer educational information and are often used on trails.

The street environment is generally signed with directional, cautionary and regulatory signs and markings as specified by the MUTCD.

Trails, and sometimes community bicycle networks, are signed with identifying names and logos. In some cases, inter-jurisdictional trail systems share a logo, as is the case of the Cedar Valley Lakes Trail System in Waterloo and Cedar Falls, Iowa.

Additional information about trail signing can be found in Chapter Four of Iowa Trails 2000. Signing of bicycle and pedestrian facilities is discussed as it relates to the facility considerations that follow.

Amenities

The general environment surrounding a specific facility will influence the level of user comfort. Amenities, provided by the public and private sectors, can enhance the trail experience and increase the economic benefits of the trail Benches, water fountains, bicycle parking facilities, and pull out bays for maps along trails all make using trails, bikeways and sidewalks more pleasant. Additional amenities that encourage bicycle and pedestrians are casual restaurants, outdoor cafes, bike shops, gas stations and mini-marts, public toilets and pedestrianized central business districts. The Cities of Ames, Waterloo, Des Moines and many other Iowa communities have revitalized their Central Business Districts to encourage walking to shop and to enhance the enjoyment of public spaces.

Shared Roadways

Some streets are useable as is for bicycle travel. These include many residential streets, and some collectors and minor arterials. Major arterials and many minor arterials and collectors require some type of improvement to accommodate most bicyclists. The ideal on-street bicycle network is made up primarily of minor arterials and residential collectors. These are generally through streets that do not have the very high speeds and volumes of major arterial roadways.

Removing Hazards

"To varying extent, bicycles will be used on all highways where they are permitted," (AASHTO, 1999). Therefore, all roadways should be made as safe as possible for bicycle travel.

Bicyclists, even more than motorists, need a smooth, debris-free pavement. Certain design features that can make any roadway a safer place for bicycling include:

• Signals that can be activated by a cyclist.
• Pavement markings placed over the most sensitive part of a loop so that cyclists know where to position themselves to trip the light.
• Bike-friendly railroad crossings with rubberized crossings and/or a widened pavement that allows a cyclist to cross tracks at right angles.
• Bike-friendly drainage grates without slats that run parallel to the curb and “eat” bicycle tires.
• General attention to maintenance needs at the right-hand edge of the roadway.

Increasing Lane Width

"Width is the most critical variable affecting the ability of a roadway to accommodate bicycle travel," (AASHTO, 1999). This does not necessarily mean that all roads should be widened. Lane widths can sometimes be re-configured to provide a wider outside travel lane (12-foot to 14-foot) for shared bicycle, motor-vehicle use.

Special Considerations

• Wide curb lanes on arterial roadways improve the cycling environment but are not designated bicycle facilities.
• A wide curb lane integrates bicycle and vehicle traffic and forces recognition and awareness on the part of motorists, particularly at intersections.
• Wide curb lanes on urban arterials accommodate bicycle use, whereas, striped and signed bike lanes accommodate and encourage increased bicycle use.
• Shared lanes should not be wider than 14 to 15 feet; greater width encourages motor vehicles to double up; if more than 15 feet of space is available, bicycle lanes should be considered.

Paving Shoulders

Paved and maintained shoulders improve conditions for bicycle travel on roads without curb and gutter.

Special Considerations

• Shoulders must be paved and maintained to a surface standard equivalent to regular travel lanes.
• Paved shoulders that are intended for bicycle use should continue through intersections and should not be routinely used as right-turn lanes for vehicular traffic.
• Rumble strips should not be used on shoulders designated for bicycle travel; if used, additional paved width (4 feet) for cyclists should be provided on the right side of a narrow rumble strip.
• Shoulders may be designated as lanes for preferential bicycle use through appropriate signage and pavement markings if they meet the recommended AASHTO width of four feet or greater. (See section below on bicycle lanes for additional considerations).

Bicycle Routes

Bicycle routes are shared roadways that are signed for preferential use by bicyclists. Bicycle route signing is recommended for relatively low volume, low speed streets that form part of a bicycle facility network that serves destinations of importance to bicyclists.

Special Considerations

• Hazards to bicycle travel should be removed from designated streets.
• Signed routes should serve a destination unless the purpose of the route is to explore a certain neighborhood, such as an historic district.
• Supplemental information added to bicycle route signing to indicate direction and distance to destinations is very useful.

Sidewalks As Bicycle Routes

It is generally inadvisable to sign sidewalks as bicycle routes. Even very wide sidewalks do not necessarily add to the safety of bicyclists, since a wide width encourages faster bicycling and increases the potential for conflicts with pedestrians and with motor vehicles at intersections.

Special Considerations

• Sidewalk facilities may be used as bikeways for short distances to provide system continuity where the roadway is not appropriate for bicycle travel.
• Sidewalks may be used as bikeways on narrow bridges.
• Sidewalk riding by young children is common and acceptable.

Bicycle Lanes

Bike lanes are striped portions of the roadway designated for preferential use by bicyclists. The lanes must be a minimum of 4 feet in width (5 feet where adjacent to parking), exclusive of curb and gutter. Bicycle lanes have been shown to increase the predictability of movements by bicyclists and motorists.

Special Considerations

• Bike lanes should always be placed to the right of the travel lane and to the left of the parking lane.
• Bike lanes are one-way facilities.
• Pavement-markings indicate direction of travel.

Bike Lanes At Intersections

Intersections present special problems for bicyclists. However, where space is limited due to multiple turn lanes, the approaching bike lane may be dropped in advance of the intersection, whereby the cyclist assumes proper lane position to proceed straight, and then picks up the designated bike lane on the other side of the intersection.

Special Considerations

• "Bike lane stripes should not be installed across pedestrian cross-walks; and in most cases should not continue through any street intersections," (AASHTO, 1999).
• AASHTO provides guidance for bike lane treatments at various types of intersections.
• Bicycle lanes are generally designated by pavement markings and symbols.
• The diamond symbol previously used on signs and as a pavement marking should no longer be used for bike lanes.

One-Way Streets

One-way streets can be difficult for bicyclists. Legally, bicyclists must ride with traffic. On one-way streets, bicyclists often use the sidewalk or ride against traffic, a significantly hazardous practice. Some communities provide bike lanes on matched one-way streets. Cyclists can also be given the legal right to ride the “wrong” way on a one-way street in a contra-flow lane, when other options are not available.

Contra-Flow Bicycle Lane

Design solutions need to include elements to make both motorized and non-motorized users aware of the special conditions that exist on a one-way street that incorporates a contra-flow bike lane:

• The contra-flow lane should be signed and marked 4 to 6 feet from the left curb with a “centerline” stripe and pavement stencils for bikes only.
• The entire contra-flow bike lane may be colored blue or red to make the unusual situation highly visible.
• A regular bicycle lane is typically provided on the right side of the street.
• On-street parking may or may not be present on the side that flows with vehicular traffic but is not recommended on the contra-flow side.
• Each intersection is signed for two-way bike traffic and one-way motor vehicle traffic.
• Special treatment should be installed at signals to provide a clear green for wrong-way bike traffic.

 

Finding Space For Bike Lanes

There are several ways to find space on roadways (short of pavement widening) for bike lanes. The Oregon Department of Transportation recommends the following considerations when looking at an existing roadway for bicycle lane opportunities.

Reducing Number of Vehicular Travel Lanes

Many one-way couplets were originally two-way streets. This can result in an excessive number of travel lanes in one direction.

On two-way streets with four travel lanes and a significant number of left-turn movements, re-striping for a center turn lane, two travel lanes, and two bike lanes can actually improve traffic flow. (See Appendix Five, "Do We Really Need 4 Lanes of Traffic?")

On other streets, continuous center lanes may be present in areas with no adjacent land uses to generate turning movements. This center space can thus be reallocated to bicycle lane space.

Reassess the Need for and Configuration of On-Street Parking

Parking can be narrowed to 7 feet, particularly in areas with low truck parking volumes, as today's cars are smaller.

In some cases, parking may be needed on only one side to accommodate residences and/or businesses. Note: It is not always necessary to retain parking on the same side of the road through an entire corridor.

Diagonal parking takes up an inordinate amount of roadway width. It can be hazardous, as drivers backing out often have poor visibility of oncoming traffic. Changing to parallel parking reduces availability by less than one-half of total parking space.

Shared Use Paths

Shared-use paths or trails, made of asphalt or concrete, should be 10 to 12 feet wide. They should be separated from the roadway system and designed for use by bicyclists, pedestrians, in-line skaters and other non-motorized users. Sidepaths are shared-use paths that immediately parallel roadways, like extra-wide sidewalks.

• Multi-use paths and trails are most appropriate within undeveloped linear park-type corridors, such as abandoned railroad beds, along stream banks, and within utility rights-of-way.
• Care must be taken to properly locate and sign/mark intersections of paths with streets and roadways.

Special Considerations

• Contrary to popular belief, a sidepath rider is more likely to be involved in a collision with a motor vehicle than a cyclist on the street.
• Thus, for non-motorized user safety, sidepaths should be considered only when the following criteria can be met:
• There are relatively few intersecting streets and there are good sight triangles, including driveways.
• The path parallels a high-speed or high-volume roadway with poor on-street riding conditions.
• There is 15 to 20 feet of barrier-free space adjacent to the road for path and clear zones.

Bicycle Parking

A component not to be overlooked in any local bicycle plan is the provision for adequate bicycle parking destinations. Investments in bicycle parking will:

• Increase overall parking capacity at little cost.
• Eliminate the clutter, pedestrian hazards and tree damage from randomly parked bicycles.
• Let people know that they and their bikes are welcome to shop locally.
• Attract additional users to the bicycle system.

Short-Term

Short-term bicycle parking facilities include those racks where a cyclist can lock up quickly and easily. Racks that are complicated to use, or any old-fashioned racks that only hold the wheel of the bicycle, should be avoided.

Recommended short-term bicycle parking racks meet the following criteria:

• Simple design that can be permanently installed in the ground.
• Accept the popular U-shaped bike locks, as well as cables and chains with padlocks.
• Allow a cyclist to easily lock the bike frame and one wheel to the rack.

Long-Term

Long-term bicycle parking should be encouraged in areas where it is necessary for employees, transit commuters or tenants to park for more than two hours. One simple way to provide long-term parking is to allow bicycles to be brought and stored inside the workplace. Other options include installing high-security racks, bicycle lids, bicycle lockers, and/or designating locked rooms or cages for bicycle storage.

Recommended long-term bicycle parking facilities should provide:

• A fully enclosed, secure space for the bicycle, or
• A rack that can secure the frame and both wheels without removing either wheel.

Special Considerations

The most important considerations to ensure successful bicycle parking are a good rack and a good location. When choosing a site, consider the following:

• Racks must be convenient
  Bicycle parking must be as convenient or more convenient than auto parking. In strip developments, strive to place parking units no further than 50 feet from the main building entrance or no further than the closest non-handicap automobile parking spaces. In commercial neighborhoods, smaller racks should be dispersed along sidewalks to provide close access to multiple storefronts.

• Racks must be visible
  Parked bicycles should be easily visible from the street or adjacent to high pedestrian traffic to discourage bike theft and vandalism. Adequate lighting of the parking area is also critical.
• Racks must be accessible
  Locate racks far enough away from walls and other obstacles so that a bicycle can maneuver in and out even when other bikes are using the rack.
• Racks should not interfere with other uses
  This includes taking care not to infringe on pedestrian travel zones, as well as separating bike and auto parking areas to protect parked bicycles from being damaged by motor vehicles.
• Racks should ideally be protected from inclement weather
  Whenever possible, install bicycle parking under an existing awning or overhang, and always place racks on a paved surface.

The Sidewalk Corridor

The sidewalk corridor represents the primary transportation facility for walking. As such, the sidewalk system must be continuous and provide access to all the destinations a pedestrian would like to go. The sidewalk corridor varies in width because it should provide at least 5 feet of walking space and additional space for signs, landscaping and amenities. The sidewalk must be adequately maintained to remain useful. The sidewalk corridor is made up of three areas: the walkway area, or what is commonly called the sidewalk; the furnishing zone or parkway area; and, the frontage zone.

The sidewalk or walkway is the area intended for pedestrian travel. Sidewalks separate pedestrians from traffic; must be continuous and well maintained; and, should be a minimum 5 feet in width in residential areas and 6 to 8 feet in commercial areas.

Special Considerations

• The Americans with Disabilities Act (ADA), requires that a useable area of at least 3 feet be provided within the walkway and that it should have a cross slope of no more than 2 percent.
• Surface should be firm, stable and resistant to slipping.
• Sidewalks should cross driveways; the sidewalk surface and grade should be maintained across the driveway.
• Pavement markings and/or traffic controls can further demarcate the pedestrian zone.

The furnishing zone or parkway planting strip separates the sidewalk from traffic and provides an area for landscaping, lighting, signs and utilities. Transit stops are located in the furnishing zone. It varies in width but should be between 4 and 6 feet wide. Landscaping and appropriate lighting create a more pleasant walking environment.

Special Considerations

• On residential streets the parkway plantings contribute to the ambience of the neighborhood and cool the walkway.
• In commercial areas the furnishing zone can be paved or planted; it is usually desirable to include planters and trees even where it is paved.
• Major arterials often lack an adequate furnishing zone:
• a worn path is often visible in the grass

• the sidewalk is immediately adjacent to travel lanes, and/or
• the walkway is interrupted with utility boxes and light poles.
• Every attempt should be made to provide an adequate, continuous walkway, separated from traffic by a furnishing zone, along arterial streets.
• The comfort and safety of transit use should be maximized with paved landing areas, transit shelters and un-obstructed walkways.

The frontage zone is a space from a few inches to several feet in the area between the walkway and the adjacent property line. This zone provides a comfortable shy distance for pedestrians from walls, fences and bushes. Sometimes outdoor cafes, benches and planters fill the frontage area.

Special Considerations

• Sidewalk amenities such as canopies, signs, flags, fences and planters are allowable but should not block the walkway.
• ADA requires that building appurtenances may not project more than 4 inches (100mm) in the frontage area between the heights of 2 feet 3 inches (686 mm) and 6 feet 8 inches (2030 mm).

Crossing Streets

There are two types of crosswalks:

• Unmarked
• Marked

The crosswalk is the natural extension of the sidewalk as the pedestrian crosses the street. Crosswalk markings are used to clarify and visually enhance the pedestrian crossing area where pedestrians can be expected in significant volumes. They are always installed at signalized intersections with pedestrian signal heads. Priority locations for the installation of marked crosswalks, include:

• Approved school crossings and along recommended safe school routes.
• Areas of substantial conflict between motorists and pedestrians.
• At arterial crossings in central business districts.
• Wherever there is a need to clarify or to increase the visibility of the crossing area.

Special Considerations

• Crosswalks should not be marked indiscriminately because motorists may cease to notice or respect their significance.
• If warranted by demand, mid-block pedestrian crosswalks can be marked.
• Mid-block crosswalks should not generally be installed if an intersection is within 400 feet of the location.

Several crosswalk marking designs are in common use. The ladder and zebra stripe markings are useful where extra visibility is desired.

Median Refuge Islands are used to assist pedestrians who must cross wide streets. Refuge islands should be a minimum of 6 feet wide and 12 feet long. They are safer when raised and constructed with barrier curbs. Curb cuts must accommodate wheelchairs and are sometimes used by bicyclists, as well.

Special Considerations

• Median refuge islands are appropriate for crosswalk distances that are greater than 60 feet.
• Are appropriate at complex intersections and for some mid-block crosswalks.

Right-Turn Lane Islands allow pedestrians to deal with just one vehicle movement at a time. This is especially important where the curb radius is large and vehicle turning movements are relatively fast. Right-turn slip lanes can pose difficulties for pedestrians, especially if designed to allow continuous right turns. For pedestrians it is best if turning vehicles must yield to cross traffic in order to create a phase for pedestrians to cross.

Special Considerations

• Right-turn lane islands shorten legs of crossing and increase visibility and site lines
• Channels turning vehicles

Raised concrete medians that provide left turning bays have been found to be safer than dual left turn “scramble” lanes. When medians are landscaped, they contribute to the attractiveness of the roadway and create human-scale boulevards instead of utilitarian and intimidating arterial roadways.

Special Considerations

• Medians are appropriate for multi-lane roadways
• Increase pedestrian and vehicle safety
• May be landscaped to provide a pleasant roadway
• Are safer than two-way left turn lanes

Crosswalks at angled intersections should be located as close as possible to a ninety degree angle with the intersecting street. This configuration shortens the pedestrian crossing distance. Shorter distances are safer for pedestrians and allow for optimal timing of traffic lights.

Special Considerations

• Crosswalks that are perpendicular rather than angled provide shorter crossing distances and are, therefore, safer.
• In some cases, a 90-degree crossing requires that the crosswalk be offset from the corner.

Recessed Stop Lines are especially important where multiple travel lanes and multiple turning lanes can block the driver’s view of crossing pedestrians. The driver has a larger field of vision when stopped further back from the crosswalk. Since the driver might have difficulty seeing intersecting traffic if stopped too far back from the intersection, various considerations must take place when deciding how far back to place the stop line.

Special Considerations

• Recessed stop lines increase driver site lines.
• Are appropriate on multi-lane and one-way streets.

Street Corners

Street corners concentrate pedestrian activities and should be designed to make the pedestrian experience safe and pleasant. The corner is the staging area for street crossings, houses various utility functions such as traffic signal equipment, and provides services, including transit access.

Special Considerations

• Poles and other utilities should be carefully placed so that the corner is not obstructed and visibility is protected.
• Traffic controls should be clearly visible to pedestrians, not just motorists.
• The corner should be designed to prevent motorists from encroaching on the pedestrian area.
• Ramps, traffic signal call buttons and transit waiting areas should be accessible to all pedestrians, including those with disabilities.

Curb cuts/ramps must be ADA compatible in design and placement and must be adequately maintained to operate optimally. The best placement of curb cuts is that which directs the wheelchair directly into the crosswalk. Generally two curb cuts, one in each direction are preferable to one wide corner cut. Every curb cut should have a level landing area at the top and bottom of the ramp. On streets with a grade, care should also be taken to make the crosswalk level. A tactile surface that is perceptible to a blind or visually impaired person should be included in the middle area of the curb cut as it approaches the crosswalk.

Special Considerations

ADA requirements include:

• The slope of the ramp should be no more than 1:12 (8 percent).
• The cross-slope should be no greater than 1:50 (2 percent).
• Every ramp should have a landing at the top and bottom, the cross-slope of which should not exceed 1:50 (2 percent) and it should be 4 feet (1220 mm) in length.
• The width of the ramp and the landing should be at least 3 feet (915 mm).

Curb Bulbs and Extensions effectively narrow the intersection, causing motor vehicles to slow down when approaching the intersection, while shortening the crossing distance for pedestrians. Pedestrians can see and be seen better at extended curbs. The additional corner space can be used for benches, bicycle parking and landscaping, as well as other pedestrian amenities. In general the smaller (tighter) the corner radius, the better the condition is for pedestrians. Advantages include a larger pedestrian area, more flexibility in the placement of curb ramps, a shorter crosswalk, and slower vehicle turning movements.

Special Considerations

• Larger corner radii create longer crossing distances and encourage faster vehicle turns.
• Curb Bulbs/Extensions improve pedestrian site lines and visibility.
• Shorten crosswalk distances
• Provide space for sidewalk amenities
• The “effective radius” of tight corners can be adequate for larger vehicles where cars are parked.

It is critical that lighting is adequate at corners so that pedestrians are visible to motorists at night. Nicely designed lighting also enhances the pedestrian environment.

Special Considerations

• Adequate lighting increases pedestrian safety.
• It is especially important at the intersections of high volume, high speed roadways and at transit stops.