The New TAC GDG Bike Section

This blog post started out as a series of tweets as I was going through the new Transportation Association of Canada (TAC) Geometric Design Guide (GDG) for Canadian Roads, Chapter 5 - Bicycle Integrated Design. While the tweets become nested and confusing to follow, I figured it was worth recreating here. So read on for a quick overview of the new guidelines for bicycle infrastructure in Canada.

• ​Shifts focus from "bicycles as vehicles" to "people riding bikes", considers human and community needs to encourage bicycle riding.
• Bike chapter guidance is focused on designs that encourage the "interested but concerned" rider, approx 60% of the population.
• Perceptions of safety critical to design given the vulnerability of cyclists relative to other modes.
• Designers must understand which characteristics motivate or deter potential and existing cyclists.
• People biking need sufficient operating space, separation from those with large speed diff, smooth surfaces, speed maintenance, connectivity
  • ​Operating space typically 1.2m to 1.5m (not including clearance) and allows for variation in tracking, typically higher uphill.
  • Operating space may be required for stationary bikes (1.8m) waiting to cross roadway, should consider trailer/cargo bikes (up to 3m).
  • Typical bicycle speeds are 15-30 km/h, maybe 50 km/h+ downhill, if no physical barrier, speed differential should not exceed 20-25 km/h.
  • If speed differential is greater than 25 km/h, separated bikeways should be provided or vehicle speed reduced through design.
  • for cycling to be effective as transportation, people must be able to maintain their momentum without having to slow too often.
  • Where reasonable, bike routes should be continuous, minimise steep grades, rough surfaces, sharp corners, intersections, and need to yield.
  • Surfaces should be even and firm, clear of obstacles and debris, wider if uneven to allow maneuverability, consider 4 season maintenance.
  • Re. connectivity, network should allow movement in various directions, offer route choice, be intuitive, direct, minimize diversion.
• Bike facilities graded on perception of safety, protected bike lanes safest, followed by regular bike lanes, local streets, other streets.
• Separated bike facilities include bike lanes (unbuffered, buffered, protected), bike paths, multi-use paths.
  • Bike lanes whether unbuffered, buffered, or protected require bicycles to operate in parallel with vehicles, especially at intersections.
    • To maintain the functionality of a bike lane, it is necessary to prevent frequent blockage by stationary motor vehicles.
    • Blockage of bike lanes by vehicles can be reduced through regulations, signage, and enforcement.
    • Lane widths, practical lower limit 1.5m, recommended range 1.8-2.1m, where bicycle volume > 1500/day, upper limit preferred to allow passing.
    • If bike lane is adjacent to parking, 2.1m width recommended (essentially allows 0.6m door zone plus 1.5m operating space).
    • Widths lower than the recommended lower limit (1.8m) should only be used under constrained conditions. Must explain context and trade-offs.
    • Painted buffers can be used between travel lanes of parking lanes to increase separation. typically hatched to prevent ambiguity of area.
    • Buffer widths, practical and recommended lower limit 0.3m, or 0.6m adjacent to parking, recommended upper limit 0.9m but can be larger.
    • A step up from the buffered lane is the protected lane, delineated by a vertical barrier of some form, also known as a "cycle track".
    • Protected bike lanes typically positioned next to the curb or on the curb side of a parking lane, can be unidirectional or bidirectional.
    • Protected lanes should be wider to allow passing, typically more passing as they are safer and see higher volumes and varying abilities.
    • Width should also consider needs of maintenance vehicles such as sweepers or snow clearing equipment.
    • Recommended lower limit width for 1-way protect lane is 2.1m, 1.8m lane + 0.3m delineator, upper limit is 3.5m, 2.5m lane + 1.0m delineator.
    • Recommended lower limit width for 2-way protect lane is 3.3m, 3m lane + 0.3m delineator, upper limit is 4.6m, 3.6m lane + 1.0m delineator.
    • Where the protected lane is located between the curb and parking, the delineator space should be at least 0.6m to allow for the door zone.
    • Lower widths may be acceptable if constrains prevent recommended range, but will restrict passing, ok for short sections only.
    • 2-way bike lanes or contraflow require special consideration at intersections and driveways, they create unexpected conflicts for drivers.
    • 1-way on each side of road preferred as adjacent vehicles and bicycles are traveling in the same direction, familiar condition for drivers.
    • On 1-way roads, 2-way bike lane should be on the left, adjacent vehicles and bikes travelling in the same direction, relative speeds closer.
    • Also, drivers making a right turn do not face oncoming bikes which is contrary to driver expectations. Left turners must still take care.
  • Bike paths are for the use of cyclists (i.e no pedestrians), but bicycles operate in parallel with pedestrians, especially at intersections.
    • Widths are similar to that of a protected bike lane, the delineator space is typically replaced by a landscaped boulevard of some form.
    • where there is an adjacent sidewalk, it will be very similar to a multi-use path with separate zones by user type.
    • So recommended width for 1-way is 1.8m to 2.5m, 2-way is 3.0m to 3.6m. Again lower may be ok where constraints dictate.
    • If bike path is adjacent to the sidewalk, there should be tactile, coloured or grade separation to improve safety for the visually impaired.
  • Multi-use paths are for the shared use of pedestrians and cyclists, both required to operate in parallel.
    • ​These are 2-way facilities and may have shared space or separate space for pedestrians and cyclists.
    • Separate space should be considered where pedestrians account for > 20% of users and total users > 33 per hour per metre of path width.
    • Or where pedestrian are less than 20% of users but total users > 50 per hour per metre of path width.
    • Recommended lower limit width is 3.0m, upper limit width is 6.0m, may reduce to 2.7m if constraints exist.
    • Lower limit allows two cyclists to pass each other, two people walking together to pass one cyclist, two inline skaters to pass.
    • Where there are high bi-directional volumes or sight distance issues, consider centre line markings (and perhaps wider path).
    • Removable bollards suggested to limit access to motor vehicles (note: these can be safety hazard for cyclists, often not wanted).
    • Where multi-use path is in a highway ROW, should be located outside of clear zone (anticipated range of errant vehicles, typically 2-14m).
    • ​If not possible to position path out of the clear zone, physical barrier should be provided, and path out of range of barrier deflection.
• Time to move on to shared spaces with motor vehicles, which may be a reasonable option if traffic speeds and volumes allow.
  
  • Bicycle boulevards typically provide a continuous corridor for bikes while reducing traffic volumes, speeds, and limiting through trips.
    
    • At intersections, traffic calming can include diagonal diverters, bicycle crossable medians and traffic circles.
      
    • Where there are 2-way stops, it should be on the cross-street to allow cyclists to maintain their speed.
      
    • Between intersections, traffic calming such as bike crossable chicanes or speed humps can be considered to reduce vehicle speeds.
      
    • At major intersections, bicycle signals, bicycle detectors or bicycle friendly push buttons should be provided.
      
    • In terms of pavement markings, sharrows are reasonable in this context to identify the route as a bike route and make drivers more aware.
      
  • Next is shared roadways (not to be confused with shared lanes), these are typically narrow with parking on either side.
    
    • ​The narrow width is wide enough for only one direction of traffic, opposing vehicles must yield and pull into gaps in parking.
      
    • This encourages lower vehicle speeds and volumes and is therefore more comfortable for cyclists.
      
    • Shared roadways are generally suitable where the posted speed is 40 km/h or less and the ADT is less than 2500 veh/day.
      
  • Shared lanes are general purpose traffic lanes with sufficient width to accommodate a car and cyclist side by side or single-file.
    
    • ​Many people are not comfortable cycling on such facilities, so where these are prevalent, they suppress cycling demand.
      
    • They may be appropriate where a separated facility is available on an adjacent corridor or if vehicle speed/volume is low.
      
    • Sharrow markings are used to signify a shared lane, placement should be where the person is expected to ride (i.e. away from parked cars).
      
    • ​For side-by-side operation, the lower limit lane width is 4.3m, upper limit is 4.9m, for single file, lane width should be less than 4.0m.
      

This page is a work in progress as I go through the new guidelines, check back for updates over the next week or two. Currently on Page 28 of about 80.

​Also don't forget to check my flickr albums where there are separate albums for bike lanes, buffered lanes, protected lanes, bike paths, multi-use paths and all sorts of other transportation infrastructure.