In January, NACTO published the third edition of Urban Bikeway Design Guide, its first update in a decade. The new edition goes beyond a kit of parts to a more complete how-to manual for designing safe, bikeable, inviting streets. Soon, we’ll make the Urban Bikeway Design Guide available for free on our website. In the meantime, we’re posting excerpts each week here on our blog. Can’t wait until the Guide is on our website? Buy it from Island Press, and use code UBDG3 for 20% off.
Today’s excerpt is from Section 4.2: Unsignalized Intersections.
Geometric design and traffic control provide safe connectivity where bikeways cross streets without the assistance of traffic signals. Bikeway crossings over minor streets, driveways, and major streets present distinct opportunities to improve transportation safety and mobility for all street users. A comprehensive approach to intersection design includes these steps:
Step 1: Evaluate for lane reductions. Consider lane reductions for multilane streets that cross bikeways. Many streets have excess motor vehicle capacity at unsignalized intersections and midblock crossings that leads to high speeds and aggressive movements. Limit the number of lanes at crossing points with a combination of medians, lane reductions with merge signs, and turn-only lane designations.
Step 2: Apply roundabout concepts. Roundabouts slow traffic and improve visibility, increasing safety and comfort of people walking, biking, or rolling and can be used in both small and large intersections. At small intersections, neighborhood traffic circles or mini-roundabouts are also appropriate. If a roundabout isn’t possible due to project constraints, designers can still apply elements of roundabout design such as intersection setbacks and crossing islands.
Step 3: Reduce speed and volume. Manage motor vehicle speeds to minimize crossing difficulty. Improve the safety and comfort of the bikeway with traffic-calming measures along all streets approaching an intersection or volume management strategies to shift turning movements away from the crossing location. At the intersection, consider methods to make yielding and turning safer, such as raised crosswalks, approach speed humps, crossing islands, parking restrictions, curb extensions, and appropriate lighting.
Step 4: Identify appropriate intersection control. Intersection control should generally be evaluated after speed reduction measures have been selected. Yield signs, stop signs, or red indications can be used to assign the right-of-way to people on bikes instead of allowing conflicting motor vehicle movements. In lower-volume and lower-speed intersections, assign priority to bikeways by placing stop control on streets crossing bikeways or by applying geometric designs to create all-yield conditions. More intensive traffic controls, such as half-signals or midblock signals, are appropriate when bikeways cross higher-volume or higher-speed streets.
Step 5: Use crossbikes and crosswalks. Crossbikes and high-visibility crosswalks should be used at bikeway intersections. Crossbike options include those with green bars with dotted white lines, green and white ‘elephant’s feet’, and solid green. High-visibility crosswalks positively impact yielding behavior in low-speed, low-volume intersections of two-lane streets and should be considered at all uncontrolled crossings.
Credit: City of Milwaukee
