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InTransition Magazine : Transportation Planning, Practice & Progress

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Insider Insight

On-Street Protected Bike Facilities Boost Mobility While Lessening Congestion

By Samuel I. Schwartz, PE

Samuel I.  Schwartz is the president, chief executive officer and founder of Sam Schwartz Engineering. He has nearly 40 years of experience in the field of transportation engineering and traffic safety. He is a former New York City traffic commissioner and the chief engineer for highways, bridges, ferries and other New York City infrastructure.

About Insider Insight

  • Insider Insight offers experts an opportunity to highlight research, projects, trends or technologies impacting the transportation sector.

When I was an assistant transportation commissioner under New York Mayor Ed Koch in 1980, I introduced the first on-street protected bike paths in the United States on Manhattan’s Fifth, Sixth and Seventh avenues and Broadway. They were short-lived. Too few people used them, according to the media and general public, and three fatal crashes where cyclists struck pedestrians elsewhere in Manhattan at around the same time made the front pages. In a conversation with then President Jimmy Carter in his limousine, New York Gov. Hugh Carey, sitting next to Koch as they rode up Sixth Avenue, pointed to the bike paths and said, “See how Ed’s pissing away your money?” I was called into Koch’s office immediately afterwards and told to remove the paths.

A cyclist travels down a green, bike-only lane on Kent Avenue

in Brooklyn, N.Y.

In 2007, on-street protected bike paths returned to Ninth Avenue in New York. Today, New York has over 10 miles of them and plans for more. Other U.S. cities, including Portland and Washington, D.C., are experimenting with protected bike paths. More cities have plans for future paths, including Toronto and Seattle. Thirty years after the removal of my original paths, my consulting firm, Sam Schwartz Engineering, is designing protected bike paths in Newark—a first for New Jersey.

Despite the benefits associated with cycling, the U.S. bicycle modal share for work trips has hovered near 1 percent for decades. On-street protected paths, aka cycle tracks, may boost that significantly. They are defined by a physical barrier between bicyclists and motorists. They differ from greenways in that they are typically created within existing curb-to-curb space by removing a travel lane for cars or by narrowing existing lanes.

Research shows such treatments can increase the cycling population. In Europe, numerous cities that have introduced such treatments have cycling rates greater than 10 percent—in some cases dramatically so. Even a relatively small shift from automobiles to bicycles can allow gridlocked streets to flow freely. Recognizing this, innovative cities have taken advantage of cycling’s ability to significantly increase mobility without adding automobile traffic to already congested streets.

Portland bicycle planners and engineers offer a useful model that provides some explanation for the U.S.’s traditionally low cycling rates. They consider 1 percent of individuals to be “strong and fearless” cyclists—those willing to ride in traffic without bicycle facilities, and often ride long distances. The “enthused and confident” riders represent perhaps 7 percent of the population and are comfortable riding in traffic with appropriate bicycle facilities. Most people (perhaps 60 percent) fall into the “interested but concerned” category:  they are not comfortable riding in traffic, but will ride in low-volume, low-speed neighborhood streets and greenways. The final “no way, no how” (around 33 percent) are those with no interest in bicycling, no matter what facilities exist.

Based on Portland’s model, cities can never achieve a bicycle modal share of greater than about 8 percent without the development of bicycle facilities meeting the needs of “interested but concerned” riders. U.S. designers traditionally follow a hierarchy of bicycle facilities: no treatments on quieter neighborhood streets; conventional bike lanes for busier streets; and for wide, busy arterials, parallel greenways are appropriate. But there is a significant gap in this hierarchy: a bike path design for higher speed, higher volume streets that don’t have sufficient room for a parallel greenway—aka, a typical urban arterial. Bike lanes on such streets are insufficient to attract more than strong and fearless riders and a smattering of enthused and confident riders. 

The most economical protected bike path design involves removing a travel lane or narrowing overly wide lanes and moving on-street parking a minimum of seven feet off the curb. The resulting space between the curb and the “floating” parking is wide enough to accommodate a bike lane adjacent to the curb and a buffer between the bike lane and the parked cars to prevent “dooring” of cyclists by motorists opening a car door into an on-coming cyclist.  If necessary, the space is made wide enough to accommodate snowplows and/or street sweepers.


A rider uses the protected bike lane on Ninth Avenue

in Manhattan.

Striping delineates the bicycle space, the buffer zone, and the parking area (or if the budget permits, the buffer zone is a raised median). The bicycle lane may be painted green to convey further that the space is for bicycles, and overhead signage may be used as well. A critical design feature is a raised pedestrian refuge in the crosswalk between the bicycle space and the automobile travel lane; without this refuge, pedestrians are likely to loiter unsafely in the bike path while waiting to cross the street.

Another important feature is a “mixing zone” at intersection approaches, in which parking is replaced by a turn bay for vehicles, allowing cyclists and motorists to become aware of each other and safely negotiate the space. If the volume of turning vehicles is high, separate bicycle and car signals may be installed to prevent right-turning vehicles from conflicting with through-traveling cyclists. 

On streets with little on-street parking, a more expensive design may be necessary.  Common in Europe, one such design creates a bike path raised a few inches above street level.

In addition to increasing bike modal share, recent safety statistics from New York show the safety value of protected bike paths for all street users: injuries to cyclists down 57 percent, injuries to pedestrians down 21-29 percent, injuries to all street users down 31-56 percent, sidewalk riding down 84 percent. Typically, protected bicycle paths also have a general traffic-calming benefit, and slower vehicle speeds equate to reduce likelihood of pedestrian death in a crash. 

Why the slow start with the implementation protected bike paths in the U.S.?  The bibles of street design, the Federal Highway Administration’s Manual on Uniform Traffic Control Devices and the American Association of State Highway and Transportation Officials’ Guide for the Development of Bicycle Facilities have largely determined U.S. bicycle facility design. The vehicular bicycling movement, which encourages cyclists to emulate the “strong and fearless” who do not require specialized bike facilities, influenced the development of both guides. The U.S. guides do not mention protected bicycle paths, and U.S. designers have turned to guides such as the Dutch CROW Design Manual for Bicycle Traffic. Vehicular cyclists who may prefer to ride faster than is conveniently possible on a protected bike path can still ride in faster mixed traffic with automobiles, unless prevented from doing so by local law.

Recognizing the potential for bicycling, the National Association of City Transportation Officials is developing its Urban Bikeway Design Guide, scheduled for publication in 2011, which will include protected bike paths among other innovative designs. Finally, we can all find a better path when it comes to cycling.

Douglas E. Adams, AICP, contributed to this column. Adams is an associate and project manager with Sam Schwartz Engineering.

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