18.2 Planning and Context
18.2.1 Bicycle Planning Principles
Effective bikeway design and network planning often leads to more people bicycling by creating routes that are efficient, seamless, and easy to use. Having a clear understanding of good planning and design principles is important as these concepts will ultimately be the foundation for the design intention and potential trade-offs that may occur. Bicycle planning principles that can be used include safety, comfort, connectivity, and cohesiveness. Descriptions of these principles are provided in
.
Principle | Notes |
Safety |
|
Comfort |
|
Connectivity |
|
Cohesiveness |
|
18.2.2 Context Considerations
Context and engineering judgment play important roles in selecting the appropriate bicycle accommodations. FHWA identifies four components that are important in identifying what type of bicycle accommodation to use: project limits, land use context, types of bicyclists the bicycle accommodation is expected to serve, and key safety and performance criteria.
As part of these overarching themes, the elements outlined below should be documented in the design process and used to determine the selection of an appropriate bicycle facility type, as discussed in the following sub-sections:
- Project Identification- Project name, project ID (CSJ), roadway name, limits, county;
- Roadway Context- Adjacent roadway functional class, speed, average daily traffic volume, project length, intersection frequency and crossing road functional classification, driveway density;
- Area Context- Land use context (see );
- Intended Bicycle Accommodation Users- Target design user (interested but concerned or all ages and abilities);
- Approved Bicycle or Transportation Plan– ; and
- Other Roadway Users- Truck percentage and key movements, transit operation (headway) and key stops, curbside lane activity, expected pedestrian demand.
18.2.2.1 Land Use
The land use context that surrounds a potential bikeway may influence the type of users (e.g., target design user), the number of users, and the potential interactions of other roadway users with the facility. For the purposes of bikeway selection, the five context classifications listed in
have been consolidated into the following two groupings:
- Urbanized which includes the Urban Core, Urban, Suburban and Rural Town Contexts; and
- Rural Contexts
18.2.2.2 Speed and Volumes of Motor Vehicles
There are many factors to consider when selecting and designing bikeways, with motor vehicle speed and volume as the initial determinants of suitable bicycle facilities. The influence of speed and volume on the safety and perceived safety or comfort of bicycle riders is an important factor and the respective criteria for appropriate speeds and traffic volumes is contained in the subsequent guidance.
For purposes of this bicycle guidance when a speed criteria is mentioned it will mean the higher of the design or posted speed (speed limit). The vehicular ADT or traffic volumes referenced pertain to existing conditions. The respective sidepath, or bicycle volumes referenced pertain to existing conditions or anticipated beginning conditions. Refer to
website for additional resources and information on bicycle and pedestrian count guidance. Note that the anticipated growth in usage should also be considered when defining the footprint for the bicycle accommodations.
18.2.2.3 Other Factors
Other factors that should be considered in the selection of bikeways are listed in the
and summarized in
Factor | Description and Design Considerations |
Unusually high motor vehicle peak hour volumes | On roadways that regularly experience unusually high peak hour volumes, more separation can be beneficial, particularly when the peak hour also coincides with peak volumes of bicyclists. |
Traffic vehicle mix | Additional separation between bicyclists and motorists is particularly important on moderate volume to high-volume streets where heavy vehicles are an abnormally high percentage of traffic. Higher percentages (>5%) of trucks and buses increase risks and discomfort for bicyclists due to vehicle size and weight, and the potential for motorists to not see bicyclists due to blind spots. This is particularly a concern for right turns, where large vehicles may appear to be proceeding straight or even turning left as they position to make a wide right turn movement. Visibility and awareness of bicyclists can be improved by providing:
|
Parking turnover and curbside activity | Parked or temporarily stopped motor vehicles present a risk to bicyclists. High parking turnover and curbside loading (commercial and passenger) may expose bicyclists to being struck by opening vehicle doors or people walking in their travel path. Vehicles stopped within bicycle lanes or travel lanes may require bicyclists to merge into an adjacent travel lane. In locations with high parking turnover, high ride-hailing demand, or curbside loading needs, wider bike lanes or separated bike lanes in lieu of bike lanes, can help to alleviate conflicts. This issue also encompasses locations where transit vehicles load and unload passengers within a bicycle lane or shared curb lane. |
Driveways/intersection frequency | The frequency of driveways and intersections also impacts decisions regarding the design of separation between the street and the bicycle accommodation as well as the design of driveways. Motorists need adequate sight distance to enter and exit intersections and driveways and benefit from sufficient space to yield to bicyclists. This is particularly important for sidepaths (the AASHTO Bike Guide enumerates the potential areas of conflict) and two-way separated bike lanes located on one side of two-way streets where contra-flow bicyclist may be unexpected by motorists. High driveway frequency may make a one-way bicycle facility type a preferable option. Consideration may be given to consolidating driveways as applicable. Wider buffers and clear sight lines can improve bicyclist safety. Where contra-flow bicycling occurs, additional design features that slow motorists’ turning movements and give motorists more time to see oncoming bicyclists may significantly improve safety for all users. Frequent, closely spaced driveways may limit the ability to provide vertical elements necessary to provide separated bike lanes. In these locations, buffered bicycle lanes, bicycle lanes or shoulders may be the only viable bicycle facility unless it is feasible to provide a raised bike lane at sidewalk level to provide greater separation from traffic. |
Direction of operation | For separated bikeways, a determination must be made as to whether the bikeway will be provided as a one-way facility on each side of the road, a two-way facility on one side of the road, or as two-way facilities on both sides of the road. As discussed above, the contra-flow bicyclist may be unexpected by motorists requiring additional design mitigations. This decision requires engineering judgment based on the bikeway’s role in the broader bike network, connectivity, safety impacts, the locations of destinations within the corridor, physical constraints within the ROW, and an assessment of intersection operations and frequency of driveways and intersections. |
Vulnerable populations | The presence of high concentrations of children and older adults should be considered during project planning. These groups may only feel comfortable bicycling on physically separated facilities, even where motor vehicle speeds and volumes are relatively low. Typically, these populations are less confident in their bicycling abilities and, in the case of children, may be less visible to motorists and lack both roadway experience as well as reduced traffic awareness skills. They can also create more conflicts with pedestrians when they are expected to share the same space. |
Network connectivity gaps | It is essential to consider the proposed transportation project in context of the local bicycle network. Wide, high-volume, or high-speed roadways can create substantial barriers to connectivity. Parallel alternative routes may not exist or may require bicyclists to ride several miles out of the way, adding substantial distance and travel time. Intersections between State and local roadways may feature a high number of conflict points, constrained ROW, or high-speed differential. Separated facilities can help close gaps in a low-stress network. Considerations include providing separate bicycle facilities under freeway underpasses, improving visibility of bicyclists, providing on-street connections between two major shared use paths, or routes connected to schools, major employers, parks, or other recreational opportunities. |
Transit considerations | Biking offers a valuable “first-mile” and “last-mile” connection to transit systems, effectively expanding the transit-shed around a station or stop. It is important to ensure accessibility of transit boarding areas, pedestrian crossings, and parking spaces, while also integrating the bicycle network into transit systems. Traffic laws and agency policy often address transit vehicles and bicycles in the right most lane or right side of the roadway. Some agencies have designated shared “transit lanes” for bicycle riding, but frequent bus stops or roadway design may create delays or less safe conditions for bicyclists sharing a lane with heavy transit traffic. If the preferred bikeway for a roadway is a bike lane or separated bike lane, the placement of the bike lane with respect to where pedestrians may wait or travel when boarding or alighting transit vehicles should be considered, as should the extent to which transit operations impact bicyclists’ level of comfort and safety. As noted in
, options for minimizing conflicts with transit include installing signs, pavement markings, and/or floating bus stops to provide for shared space, placing a separated bike lane on the left side of a one-way street (out of the way of transit stops along the right side), or choosing to install a separated bike lane on a nearby parallel corridor away from transit. |
18.2.3 Target Design User
Different bicycle riders may have varying tolerances associated with the importance of the individual planning principles outlined above.
indicates the array of potential bicycle riders that should be considered when scoping and designing a roadway project.
Additionally, as discussed in
, micromobility users must share facilities with other users of the transportation system and should be expected to operate within bikeways where provided. Where bike lanes are not provided, these users will operate within shared travel lanes or sidewalks which can raise safety concerns for users who might be apprehensive about walking, riding, or driving alongside these devices. Some micromobility companies advise their users not to ride on the sidewalks which relegates their users to using bikeways or sharing motor vehicle lanes. To mitigate these safety concerns bicycle networks can be expanded to also serve micromobility use.
Research over the last decade has evaluated how to classify the general population into different types of bicyclists. This research confirms that only a relatively small percentage of people can be classified as comfortable bicyclists in mixed traffic, and that a large majority of people prefer some level of separation from higher-volume, higher-speed motorized traffic. As such, in many jurisdictions across the United States, the common target design user are those who are interested in riding but concerned about safety (“Interested but Concerned” bicyclists) as this is the largest group of potential bikeway users among the general population. According to research, these bicyclists would ride more if they felt safer and, thus, are more likely to take short trips, avoiding busier arterial roadways. “Interested but Concerned” bicyclists prefer separation from vehicles and have a lower tolerance for traffic stress than more confident riders. Accommodating these users will also accommodate a wide spectrum of micromobility users.
Figure 18-1: Types of Bicycle Facility Users as a Percentage of Total General Population
To maximize the potential for bicycling as a viable transportation option, it is important to design facilities to meet the needs of the “Interested but Concerned” bicyclist user profile. Bicycle facilities which meet the needs of the “Interested but Concerned” bicyclist will generally meet the needs of all bicyclists, therefore they are considered “All Ages and Abilities” bicycle facilities because they maximize potential use. In general, more separation from motorized traffic is desirable to serve a greater number and type of users more safely.
TxDOT endeavors to provide bicycle facilities to serve bicyclists of “All Ages and Abilities” to maximize the number of people who may use the facility.
An exemption to this bikeway selection approach are situations where bicyclists are operating in large groups, or higher speed bicyclists are likely operating on a sidepath. In these situations, it is acceptable to provide multiple facility types (e.g., a wide outside lane and sidepath, or a bicycle lane and sidepath) where practicable. In all locations with bikeways, there still may remain individual bicyclist who prefer to operate at higher speeds (typically greater than 20 mph) who may prefer to operate in the travel lane.
18.2.4 General Bikeway Selection
The figures in this section provide some general guidance for the bicycle planning principles, target design user, and context discussed in the previous sections. Note, these Figures are for very general guidance and a preliminary bikeway recommendation.
provides specific design criteria and additional guidance for the application of bikeways to serve a target design user. In particular, elements associated with the respective roadway speed criteria discussed in the application discussion or each bikeway in
should be reviewed before making a final bikeway selection and choosing specific design elements. As long as the project meets the defined criteria in
for a specific bikeway,
the engineer has the discretion to select the bikeway that is best suited to the project needs and constraints.
provides an example selection process from FHWA. Note that
and
should be used to make the initial recommendation for the type of bicycle facility
Figure 18-2: FHWA Bikeway Selection Process and Guide Outline
18.2.4.1 Requirements for Selection – Urban, urban Core, Suburban, and Rural Town
For all urbanized (urban, urban core, suburban, and rural town) contexts, the following guidance is provided for various types of construction (the selection guidance is based primarily on
):
- For full reconstruction projects, new construction projects, or other construction projects whether in existing ROW or with additional ROW, the project should use for the initial recommendation for bikeway facility type. See for guidance on downgrading to the next best facility type. For the selected facility type, the geometric values should adhere to the specific guidance for that facility type. For values not provided in this guide, refer to the and, for separated bike lanes, and . Note: TAS/ requirements for each facility type must be met as well.
- For projects involving bridge replacement, bridge deck replacement, or bridge rehabilitation, the following guidance is provided:
- A 5-ft minimum clear space (4-ft shoulder and 1-ft offset measured to the toe of barrier) shall be provided on the structure and along the adjacent barrier. Off-System Bridges, with current ADT greater than 400 ADT, where this addition may represent an unreasonable increase in cost may be excepted from this requirement. See for specific off-system bridge requirements for current ADT of 400 or less. Where feasible, desirable shoulder width as shown in should be used. (This requirement is not applicable if an SUP or other bikeway is provided for bike accommodations.)
- For roadways identified on theTexas Bicycle Tourism Example Network, preferred 10-ft (minimum 8-ft) shoulder width should be provided on bridges. (This requirement is not applicable if an SUP or other bikeway is provided for bike accommodations.)
Figure 18-3: Recommended Bicycle Facility Selection for Urban, Urban Core, Suburban, and Rural Town Context
NOTE: Use the higher of the design speed and the posted speed for the speed. To be conservative when designing for all ages and abilities facilities, designers should attempt to use the higher-level facility at the respective boundary limits.
18.2.4.2 Requirements for Selection – Rural
For rural context (not rural towns), the below guidance is provided for various types of construction:
- For new construction, reconstruction, or widening projects in a rural setting where ROW is being acquired, the following guidance is provided:
- When the scoping process and environmental documentation indicates a need for bicyclist accommodations, the recommended bikeway is shown in , indicating the desirable shoulder widths for various speeds and traffic volumes. In some cases, a shared use path or other locally preferred facility type (such as a buffered bicycle lane or separated bicycle lane) may be identified during stakeholder outreach. See for additional guidance on shoulders and for shared lanes. See for guidance on downgrading to the next best facility type. Note: TAS/ADAAG requirements for each facility type must be met as well.
- Roadways indicated in should be designed with a minimum 8-ft shoulder, a shared use path, or another locally preferred facility type.
- Where new construction, reconstruction, or widening is accomplished without additional ROW, the above should be followed where feasible. See for guidance on downgrading to the next best facility type. Note: TAS/ADAAG requirements for each facility type must be met as well.
- For projects involving bridge replacement, bridge deck replacement, or bridge rehabilitation, the following guidance is provided:
- A 5-ft minimum bicycle clear space (4-ft shoulder and 1-ft offset measured to the toe of barrier) shall be provided on the structure and along the adjacent barrier. Off-system Bridges, with current ADT greater than 400 ADT, where this addition may represent an unreasonable increase in cost may be excepted from this requirement. See for specific off system bridge requirements for current ADT of 400 or less. Where feasible, desirable shoulder width as shown in should be used. (This requirement is not applicable if an SUP or other bikeway is provided for bike accommodations.)
- For roadways identified on theTexas Bicycle Tourism Trails Example Network, preferred 10-ft (minimum 8-ft) shoulder width should be provided on bridges. (This requirement is not applicable if an SUP or other bikeway is provided for bike accommodations.)
Figure 18-4: Recommended Bicycle Facility Selection for Rural Context
NOTE
: A separated shared use path is a suitable alternative to providing paved shoulders solely for the purpose of a bikeway and should be considered on Bicycle Tourism Trail Example Network segments as well as rural roads with ADT above 6000 vehicles per day. Use the higher of the design speed and the posted speed for the speed. If the percentage of heavy vehicles is greater than 5%, consider providing a wider shoulder or a separated path.18.2.5 Bikeway Feasibility Assessment
There will be locations, mostly due to ROW not being acquired, where desirable or minimum bikeway width(s) are not feasible, even after all other design criteria were analyzed as minimum values (e.g., lane widths). In these cases, it will be necessary to consider downgrading the bikeway to the next best facility type and/or to provide a parallel facility. The following should be considered when evaluating bikeway feasibility.
18.2.5.1 Prioritizing Safety
Meeting safety and mobility goals are typical objectives for roadway designers. Designers have an ethical obligation to provide for the health, safety, and welfare of the public, which may require a careful evaluation of mobility goals where they have the potential to degrade safety. One user’s convenience or mobility should not be prioritized over another user’s safety. Most roadway and bikeway design projects can be designed to improve safety for all modes.
As discussed in
, the dimensional values of bicycle facilities influence the safety and comfort of bicyclists. The impact of the use of minimum and constrained dimensional values should be considered carefully during feasibility assessments.
When a bikeway approaches a large intersection, several decisions have to be made that can impact safety. In locations with constrained ROW, the designer may have to evaluate whether to terminate a bikeway to provide an additional travel lane or turn lane. Intersections are locations where a high percentage of bicyclist crashes occur. It is preferable to maintain the bikeway to maximize safety and comfort of bicyclists. If the bikeway cannot be continued, care should be taken to ensure the transition is clear and consideration should be given to providing bicyclists an option to leave the roadway (see
for further guidance.)
Bikeways should remain consistent along a corridor. However, it may be preferable for safety reasons to increase separation as a bicycle facility approaches an intersection – for example, a shoulder could transition to bicycle lane or a bicycle lane could transition to a separated bicycle lane with a protected intersection at large intersections to minimize conflicts between motorists and bicyclists. See
for information on protected intersections.
18.2.5.2 Considerations for Alternatives
Impacts on ridership, comfort/stress, safety, and overall network connectivity should be considered when evaluating alternative bikeway designs or parallel routes to ensure the project will still meet the purpose identified at the outset. The following tradeoffs need to be considered and documented in the design process:
- Reduced or suppressed ridership where the bikeway does not meet the needs of the target design user;
- Additional length of trip when bicyclists must use a parallel route. This length should not exceed 30% more than original route;
- Failure to provide a bikeway or critical connections that leave an important gap in the bicycle network;
- Reduced safety where bicyclists must operate with relatively high motor vehicle speed and/or high-volume traffic in shared lanes;
- Reduced safety where bicyclists must operate in narrow bikeways (e.g., narrow bike lanes adjacent to high turnover parking or narrow shared use paths with high volumes of pedestrians or bicyclists);
- Reduced safety where bicyclists improperly use facilities (e.g., ride the wrong way on shared lanes, sidewalk riding, etc.); and
- Increased sidewalk bicycling where bicyclists are avoiding low-comfort/high-stress conditions.
In instances where shared use paths or separated bike lanes are recommended by volume, speed, and/or other factors, but desirable facility widths cannot be obtained, it may still be preferable to provide separated facilities with minimum or reduced paths and/or buffer widths rather than putting bicyclists in the roadway with highspeed/volume traffic
If selecting a parallel route as the preferred route to accommodate a bikeway that meets the needs of the Interested but Concerned bicyclist occurs, the provision of alternative bicycle facilities on the desired route should still be considered to accommodate the Highly Confident design user and to provide connections for bicyclists to and from properties that exist along that desired route. A typical example would be locations where the Interested but Concerned bicyclist is accommodated on a parallel, low volume local street along a bicycle boulevard because there is not sufficient width available to provide a separated bike lane on the desired route. In these instances, the provision of a bike lane or shoulder can still be beneficial to serve the more confident bicyclists on the higher volume roadway to improve their safety and access to destinations along the roadway.