As a longtime bike commuter I have watched with great interest as the design of bicycle facilities has evolved in recent years. Traditional bike lanes were a welcome addition and a good place to start, but often were not addressed through street intersections, leading to confusion and potentially unsafe conditions when bike and vehicle traffic mix. The lack of clear guidance at these conventional intersections may also contribute to a high rate of cyclists ignoring traffic signs and signals, which we’ve all seen. My colleague Jim Sandlin has previously discussed how roundabouts offer safer bicycle conditions at intersections. However, most intersections are controlled via a stoplight or a stop sign. Let’s look at some of the best new ways to integrate bike traffic in intersections.
More and more designers are committing to the “complete street” concept, which accommodates all modes of transportation. “Innovative bicycle facilities” refers to the new generation of complete street improvements designed to increase clarity and safety for cyclists, such as separated bikeways, green paint, and separate bike signal phases. There are many creative and effective solutions, but at this early stage they are being developed and implemented without a consistent set of design guidelines – at this time the Federal Highway Administration’s Manual on Uniform Traffic Control Devices lists most innovative bicycle facilities as “experimental” status, if it includes them at all. Going forward, the challenge for transportation designers will be to develop a consistent language of road elements so that all street users, regardless of vehicle, understand how to safely navigate roadways with increasing numbers of cyclists in the mix.
A recent survey in Portland had street users (regardless of type of vehicle they use) identify the type of bike rider they are:
Bicycle Forward Stop Bars
Green Pavement Paint
Two-Stage Turns (aka the Copenhagen Turn)
Mixing Zones at Turn Lanes
However in some cities entire vehicle lanes have been converted to separated bikeways. The need still exists for vehicles to cross the bikeway in order to turn, but there is not enough width to add a separate turn lane. Instead, a mixing zone is provided to allow the vehicle traffic to merge into the bike traffic before turning. This prevents sudden turns across the bikeway, and prevents vehicles waiting for an opening to turn from blocking through traffic.
Turning Restrictions for Vehicles
Separated Bikeways at Transit Stops
If a bikeway does need to cross train tracks, the route needs to cross as close to perpendicular as possible. I’ve known too many riders who have launched over the bars after getting their skinny front tire stuck in a track!
Think Complete Intersections
Clarity and consistency of signage, signals, and pavement markings. Pedestrians, cyclists, and drivers all need to be clear on how the intersection is intended to function so that they can share the road effectively.
An educational campaign targeted at all users may be necessary when the first innovative bike facilities in an area are introduced, because they are often a departure from how we are all used to using the road.
Review precedents to find successful approaches.
Busy driveways are potential conflict points and should be treated as intersections.
Visibility at corners – obstructions such as parked vehicles, signs, etc.
A successful intersection is just one link in the chain – a truly successful bike network takes careful planning to establish key corridors which are comfortable routes linking key destinations.
Reference standards for innovative bikeways:NACTO Urban Bikeway design guide
CROW Design Manual for Bike Facilities (Netherlands)
AASHTO Guide for Development of Bicycle Facilities
City design manuals: Minneapolis, Chicago, Portland, New York City, San Francisco
State DOT bicycle design manuals
MUTCD – upcoming version will have more content for innovative bikeways
Reference standards for traditional bikeways:AASHTO
DOT design manuals
MUTCD – currently need to apply for experimental status to go outside of traditional bikeway standards
Source references for this blog:
Bicycle Facility Evaluation. District of Columbia Department of Transportation. http://nacto.org/docs/usdg/bicycle_facility_evaluation_ddot.pdf
Evaluation of Innovative Bicycle Facilities: SW Broadway Cycle Track & SW Stark/Oak Street Buffered Bike Lanes. City of Portland Bureau of Transportation. http://bikeportland.org/wp-content/uploads/2011/02/PSUCycleTrackBBLReportFINAL.pdf
Innovative Bicycle Facility Treatments. Rick Plenge, P.E, PTOE, Fehr & Peers. http://acec-co.org/wp-content/uploads/2013/04/InnovativeTreatments.pdf
Bicycle Facilities and the manual on Uniform Traffic Control Devices. Federal Highway Administration. http://www.fhwa.dot.gov/environment/bicycle_pedestrian/guidance/design_guidance/mutcd/