Download this document
Bicycle Facilities
Bicycling is a key element of Complete Streets in Boston. The bicycle is an ideal vehicle for trips that are too far to comfortably walk, but are still fairly short. Bicycling is an excellent option for trips that are less than three miles in length, which are half of all trips made on a daily basis. The City of Boston has made considerable progress incorporating bicycling into transportation projects, retrofitting existing streets with new bike lanes, and establishing new programs that support and encourage bicycling.
Roadways
These guidelines outline two basic types of cross sections; exclusive facilities where roadway space is designated for bicycle use, and shared facilities where bicycles and other vehicles share roadway space Like pedestrians, bicyclists are vulnerable road users who can be seriously injured in a simple collision. For many people, bicycling in close proximity to faster moving traffic can be an uncomfortable experience. On streets without bicycle facilities, the competition for space can result in unsafe behavior on behalf of both motorists and bicyclists. In addition, lack of bicycle accommodations on the street can increase the number of bicyclists riding on the sidewalk, which conflicts with pedestrian traffic. Welldesigned bikeways reduce these conflicts and create a more predictable traffic environment for everyone.
III.
Exclusive bicycle facilities are the preferred facility type in Boston where feasible. In general, exclusive facilities are not appropriate on Neighborhood Residential and Shared Streets where traffic conditions support bicycling without needing separation and bicycle boulevard treatment should be considered. On streets where an exclusive facility is not feasible, the appropriate shared facility design should be provided. These guidelines provide details on the design and appropriate use of the treatments listed above. Guidance on intersection treatments for bicycles is provided in Chapter 4. The following general design considerations should be taken into account when determining the appropriate type of bikeway design for a given street.
Boston Transportation Department
Updated as of December 2010
Boston Complete Streets Guidelines
95
Download this document
94
96
Roadways
92
III.
97
99
93
100
95
98
Bike Lanes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 Left-side Bike Lanes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93 Buffered Bike Lanes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94 Contra-flow Bike Lanes . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95 Climbing Lanes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96 Cycle Tracks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97 Marked Shared Lanes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98 Priority Shared Lanes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99 Bicycle Boulevard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
96
Boston Complete Streets Guidelines
UPDATED AS OF December 2010
Boston Transportation Department
Download this document
General Design Considerations for Bicycle Facilities
III.
Roadways
>> In order to provide adequate space for bicycle facilities, road diets, lane diets and the consolidation of on-street parking should be considered. More guidance on optimizing street capacity is provided earlier in this chapter, including minimum lane widths for Boston streets. >> While it is illegal for motorists to open car doors into oncoming traffic before checking to see if it is clear, the potential hazard of opening car doors should be considered when developing an appropriate design. Design options have been provided to help reduce conflicts between bicycles and on-street parking. >> Colored pavement should be considered to increase awareness of bicycle facilities in the following ways: >> In curbside locations where there is a problem with (or likelihood of a problem with) parking or stopping in the bike lane. >> At the beginning of the block for a short distance to highlight a bike lane. >> At intersections to increase awareness of conflicts areas and increase visibility (See Chapter 4: Intersections). >> Bicyclists provide their own energy and as such are sensitive to distance. They typically seek the most direct route. Roadways should be designed to provide the most direct appropriate route and minimize convoluted or out-of-theway routing. >> Bicyclists are more sensitive to broken or uneven pavement which can cause them to lose balance or swerve suddenly. This includes uneven or sunken drainage structures and utility access covers. Where possible, the installation of bicycling facilities should be coupled with an evaluation of pavement conditions and improvements as necessary to ensure a smooth riding surface. >> Drainage inlets should be safe for bicycle wheels. >> Angled parking, if provided adjacent to an on-street bikeway, should be back-in to increase visibility of bicyclists when exiting spaces. The design treatments on the following pages should be applied based on engineering judgment and in consultation with BTD and Boston Bikes. The guidance in this document should be supplemented with design guidance provided in the Manual on Uniform Traffic Control Devices and the AASHTO Guide for the Development of Bicycle Facilities.
Boston Transportation Department
Updated as of December 2010
Boston Complete Streets Guidelines
97
Download this document
Bike Lanes
Neighborhood Residential Neighborhood Main Street Downtown Commercial Downtown Mixed-use Industrial
Overview
Use
Bike lanes provide an exclusive space for bicyclists through the use of lines and symbols on the roadway surface. Bike lanes are for one-way travel and are normally provided in both directions on two-way streets and or on one side of a one-way street. Bicyclists are not required to remain in a bike lane when traveling on a street, and may leave the bike lane as necessary to make turns, pass other bicyclists, or to properly position themselves for other necessary movements. Bike lanes may only be used temporarily by vehicles accessing parking spaces and entering and exiting driveways and alleys.
>> Bike lanes can be used on one-way or two-way streets, and on single or multilane roads. >> Bike lanes may be placed adjacent to a parking lane, or against the curb if there is no parking. >> Bike lanes are typically installed by reallocating existing street space (narrowing other travel lanes, removing travel lanes, and/or reconfiguring parking lanes). The minimum widths of bike lanes, 1travel lanes, and 2parking lanes are provided in the minimum widths chart on page TK of this chapter.
Shared Streets Neighborhood Connector Boulevard Parkway
Bike lanes are typically on the
right-hand side of the road because slower traffic normally stays to the right.
III.
Roadways
The minimum width of bike lanes is 5 feet when parking is permitted.
2
1 2
Considerations >> Bicycle lanes are normally placed on the right hand side of the road to reflect the general traffic principle of slower traffic keeping to the right. >> On one-way streets and streets with wider medians, consider a left-side bike lane (see next section). >> Where additional space is available, consider providing a buffered bike lane (see page TK). >> On constrained corridors with high parking turnover, consider providing a buffered bike lane or using parking
98
Boston Complete Streets Guidelines
T’s instead of longitudinal parking stripe to guide bicyclists away from parked vehicles. >> Wider bike lanes enable bicyclists to pass one another on heavily traveled corridors and increase separation from faster traffic.
UPDATED AS OF December 2010
Boston Transportation Department
Download this document
Left-side Bike Lanes
Neighborhood Residential Neighborhood Main Street Downtown Commercial Downtown Mixed-use Industrial
Overview
Use
In some locations, bike lanes placed on the left side of the roadway can result in fewer conflicts between bicyclists and motor vehicles, particularly on streets with heavy right-turn volumes, or frequent bus headways where buses commonly operate in the right-side curb lane. Left-side bike lanes can increase visibility between motorists and bicyclists at intersections due to the location of the driver on the left side of the vehicle.
>> On one-way streets where parking is only provided on the right-hand side, left-side bike lanes are often a better option than right-side bike lanes because there are fewer conflicts with parked cars. The same is true for two-way streets with continuous, raised center medians where onstreet parking is not provided adjacent to the median. >> On one-way streets with parking on both sides, bicyclists riding on the left will have fewer conflicts with car doors opening on the passenger side. >> Left-side bike lanes have the same design requirements as right-side bike lanes.
Roadways
Bicyclists in left-side bike lanes have less chance of being “doored.”
III.
Left-side bike lanes have a minimum width of 5 feet when parking is permitted—the same as right-side bike lanes.
Shared Streets Neighborhood Connector Boulevard Parkway
Considerations >> Colored pavement should be considered in curbside locations to increase awareness of the restriction against parking or stopping in the bike lane. >> Left-side placement may not be appropriate in locations where the street switches from one-way to two-way operation.
Boston Transportation Department
>> Left-side bike lanes may not be appropriate near the center or left side of free flow ramps or along medians with street car operations unless appropriate physical separation can be provided including signal protection where appropriate (see Chapter 4: Intersections).
Updated as of December 2010
Boston Complete Streets Guidelines
99
Download this document
Buffered Bike Lane
Neighborhood Residential Neighborhood Main Street Downtown Commercial Downtown Mixed-use Industrial
Overview
Use
Buffered bike lanes are created by painting a flush buffer zone between a bike lane the adjacent lane. While buffers are typically used between bike lanes and motor vehicle travel lanes to increase bicyclists’ comfort, they can also be provided between bike lanes and parking lanes, in locations with high parking turnover to discourage bicyclists from riding closely next to parked vehicles.
3 feet is the recommended minimum width of a buffer, however their width may vary depending upon the available space and need for separation. Buffers should be painted with solid white lines and cross hatches, per the MUTCD. >> Buffers can be useful on multilane streets with higher speeds, but are not required in these locations.
Shared Streets Neighborhood Connector Boulevard Parkway
>>
III.
Roadways
The buffer should be a minimum of 3 feet wide.
Considerations >> Where only one buffer can be installed on a constrained corridor with on-street parking, buffer should typically be used between the bicycle lane and parking lane.
100
Boston Complete Streets Guidelines
UPDATED AS OF December 2010
Boston Transportation Department
Download this document
Contra-flow Bike Lanes
Neighborhood Residential Neighborhood Main Street Downtown Commercial Downtown Mixed-use Industrial
Overview
Use
The current pattern of street directions in Boston (i.e., two-way or one-way in one of two directions) has been developed primarily to facilitate efficient movement of automobile traffic and has led to significant number of one way streets, especially in older parts of town. This, combined with the organic, non-grid nature of much of the city’s layout, often make bicycling to specific destinations within short distances difficult.
>> Contra-flow bike lanes are used on one-way streets that provide more convenient connections for bicyclists where other alternative routes are less desirable or inconvenient. >> Contra-flow lanes are less desirable on streets with frequent and/or high-volume driveways or alley entrances on the side with the proposed contra-flow lane. >> Care should be taken in the design of termini of contra-flow lanes. Bicyclists should be directed to the proper location on the receiving roadway. On streets with contra-flow lanes, a bike lane should also be included for bicyclists traveling in the same direction as traffic.
III.
Roadways
A contra-flow lane can help to solve this problem. Contra-flow lanes enable one-way streets to operate in two directions for bicycles only. Contra-flow lanes are useful to reduce distances bicycles must travel and can make bicycling safer by reducing wrong-way riding.
Shared Streets Neighborhood Connector Boulevard Parkway
Considerations >> Observations of wrong way riding may indicate the need to consider a contra-flow lane. >> A bike lane of other marked bicycle facility should be provided for bicyclists traveling in the same direction as motor vehicle traffic on the street, to discourage wrong way riding in the contra-flow lane. >> Parking is discouraged against the contra-flow lane as drivers’ view of oncoming bicyclists would be blocked by other vehicles. If parking is provided, a buffer is recommended
Boston Transportation Department
to increase bicyclists’ visibility. On-street parking should be restricted at corners. >> A double yellow line should be provided between contra flow lane and opposing travel lane. The line should be dashed if parking is provided on both sides of the street. >> Intersection design for contra-flow lanes is discussed in Chapter 4.
Updated as of December 2010
Boston Complete Streets Guidelines
101
Download this document
Climbing Lanes
Neighborhood Residential Neighborhood Main Street Downtown Commercial Downtown Mixed-use Industrial
Overview
Use
Climbing lanes are bike lanes that are provided on the uphill side of streets with steep and/or sustained grades. Bicycles travelling in an uphill direction move at significantly slower speeds than adjacent traffic, and therefore benefit from the presence of a bike lane. When travelling downhill bicycles pick up speed and can travel at similar speeds as motor vehicles, therefore shared lane markings, rather than bike lanes, are typically provided in the downhill direction.
>> Climbing lanes are used on streets with steep and/or sustained grades. >> Climbing lanes are not appropriate on streets with short, rolling hills because they would start and stop too often.
Shared Streets Neighborhood Connector Boulevard Parkway
III.
Roadways
In the downhill direction, shared lane markings direct bicyclists outside the door zone.
Considerations >> If on-street parking is provided in the downhill direction, it is particularly important to ensure that bicyclists are directed to ride in a location outside of the door zone, either by the placement of the shared lane marking, a buffer, or other means.
102
Boston Complete Streets Guidelines
UPDATED AS OF December 2010
Boston Transportation Department
Download this document
Cycle Tracks
Neighborhood Residential Neighborhood Main Street Downtown Commercial Downtown Mixed-use Industrial
Overview
Use
Cycle tracks are bikeways that are physically separated from the adjacent roadway through the use of a 1 raised median or on-street parking. Cycle tracks are for the exclusive use of bicyclists and provide added separation that enhances the experience of bicycling on urban streets. Cycle tracks can either be one-directional, or two-directional, and can be provided on both sides of two-way streets, or on one side of one-way streets.
>> Cycle tracks are typically installed on streets with higher traffic volumes and/or speeds, with long blocks and therefore fewer intersections. >> Cycle tracks can be useful on streets that provide connections to off-street trails, since bicyclists on these streets may be more accustomed to riding in an area separated from traffic. >> Intersection design (see Chapter 4 for more information) for cycle tracks is complex and requires careful attention to conflicts with turning vehicles. >> The minimum width of a cycle track is 7 feet. When adjacent to on-street parking, a minimum 3 foot buffer should be provided between parking and the cycle track. The buffer serves as a pedestrian loading and unloading zone.
Cycle tracks must be 7 feet wide at a minimum to allow ample width for passing.
Shared Streets Neighborhood Connector Boulevard Parkway
III.
Roadways
Buffer adjacent to on-street parking must provide 3 feet minimum between parking and cycle track.
2
1
Considerations >> Cycle tracks should be designed to allow bicyclists to pass one another. >> Cycle tracks require increased parking restrictions compared to bike lanes to provide for visibility at intersection transitions. >> Curb separation should be considered when parking is not present. Snow clearance will need to be considered with this option. Parking protected cycle tracks may be combined with islands at corners and crossings. >> When cycle track is provided on same side of road as
Boston Transportation Department
transit operations, 2 transit stops and waiting areas should be provided between the cycle track and the roadway to reduce conflicts between pedestrians loading and unloading, and bicyclists. >> On streets with high volumes of pedestrians and constrained sidewalks, cycle tracks may not be appropriate due to the strong likelihood that pedestrians will use the cycle track as an extension of the sidewalk. >> The presence of drainage and utility structures along the curb may reduce the effective width of the cycle track.
Updated as of December 2010
Boston Complete Streets Guidelines
103
Download this document
Marked Shared Lanes
Neighborhood Residential Neighborhood Main Street Downtown Commercial Downtown Mixed-use Industrial
Overview
Use
Marked shared lanes are shared lanes that have special bicycle markings to increase bicyclist’s comfort. The symbols (called “shared lane markings”) alert motorists of locations where bicyclists should be expected to ride and encourage safer passing behaviors.
>> Shared lane markings are typically used on streets where space constraints make it impossible to provide bike lanes. They should not be used on streets with speed limits higher than 35 mph. >> On streets with narrow lanes, the shared lane marking is typically placed in the center of the lane to indicate that motorists must change lanes to pass bicyclists. >> On narrow travel lanes adjacent to on-street parking, shared lane markings should be placed in a location that is outside of the door zone of parked vehicles.
III.
Roadways
Shared Streets Neighborhood Connector Boulevard Parkway
Considerations >> Marked shared lanes should be provided after considering narrowing or removing travel lanes, parking lanes and medians as necessary to provide exclusive facility. >> Shared lane markings may be placed on both sides of the road where there are multiple routes along a corridor. >> For multilane applications, see Priority Shared Lanes. >> On streets with an on-street parking lane that is frequently unoccupied, bicycles will often feel comfortable riding in the parking lane.
104
Boston Complete Streets Guidelines
>> Shared lanes can be used to complete connections between bike lanes and other facilities.
UPDATED AS OF December 2010
Boston Transportation Department
Download this document
Priority Shared Lanes
Neighborhood Residential Neighborhood Main Street Downtown Commercial Downtown Mixed-use Industrial
Overview
Use
On multilane streets, marked shared lane symbols can be enhanced with dashed longitudinal lines. This marked lane within the lane can reduce conflicts by encouraging (though not requiring) vehicles to use inside lanes, and reserve the outside lane for bicyclists. On streets with narrow travel lanes, priority shared lanes direct the bicyclist to the correct and most conspicuous position on the road—the middle of the travel lane.
>> Priority shared lanes are appropriate on multilane oneway and two-way streets with higher traffic volumes and speeds and limited roadway space.
Shared Streets Neighborhood Connector Boulevard Parkway
When dashed
III.
Roadways
longitudinal lanes are added to marked shared lane symbols, it denotes priority shared lanes.
Considerations >> Priority marked shared lanes should be provided after considering narrowing or removing travel lanes, parking lanes or medians as necessary to provide an exclusive facility.
Boston Transportation Department
Updated as of December 2010
Boston Complete Streets Guidelines
105
Download this document
Bicycle Boulevard
Neighborhood Residential Neighborhood Main Street Downtown Commercial Downtown Mixed-use Industrial
Overview
Use
Bicycle boulevards are quiet, often residential streets that are designed to give priority to bicycle use and to discourage through-traffic by motor vehicles. Bicycle boulevards are shared streets. Separated bicycle facilities (i.e., bike lanes) are not necessary on bicycle boulevards because speeds and traffic volumes are low. Bicycle boulevards are typically designated by special wayfinding signs and pavement symbols.
>> Bicycle boulevards are typically best accomplished in neighborhoods with a gridded street network (one street is chosen as the bicycle boulevard), but can also be accomplished by combining a series of road and trail segments to form one continuous route. >> Bicycle boulevards should be long enough to provide connectivity between neighborhoods and common destinations. >> Traffic calming measures can be used to maintain low speeds (20 mph or less) on bicycle boulevards (see recommendations for traffic calming devices in this chapter). >> Ideally, bicycle boulevards should not carry more than 1,000 motor vehicles per day to be compatible with bicycling. Diverters and other traffic management devices are typically used to discourage motor vehicle through-traffic, while still enabling local traffic access to the street.
III.
Roadways
Traffic calming devices, such as midblock neckdowns, help maintain low speeds on bicycle boulevards.
Shared Streets Neighborhood Connector Boulevard Parkway
Considerations >> At major street crossings, bicycle boulevards may need additional crossing measures for bicyclists, such as traffic signals with bicycle-sensitive loop detectors, crossing beacons, median refuge islands, and/or curb extensions.
106
Boston Complete Streets Guidelines
UPDATED AS OF December 2010
Boston Transportation Department