89 percent of bike collisions happen at intersections. DOT’s new street-design guidelines aim to slash that statistic and save lives.
DOT installed a pilot Offset Crossing intersection at Columbus Avenue and West 70th street in Manhattan. It includes buffering traffic from bicycles, shortening the crossing distance for pedestrians, and a waiting area for cyclists.
Over 1,000 miles of bike lanes snake through New York City, and every year since 2015, the Department of Transportation (DOT) has added at least 50 more miles. Streets are safertoday than in years past, but the city is far from reaching its Vision Zero goals of no fatalities from car collisions.
In 2017, 4,397 cyclists were injured in car crashes and 25 cyclists died. Parked cars and trucks routinely block bike lanes. Community boards sometimes oppose protected bike lanes.
New modes of transportation are coming, and street design is woefully obsolete.
This week, DOT published “Cycling at a Crossroads: The Design Future of New York City Intersections,” a study that proposes new intersection design guidelines that, the city hopes, will reduce collisions between cars and bikes and save lives. They include measures to increase visibility, clarify right of way, reduce vehicle-turning speed, and improve circulation at intersections.
DOT’s study found that Offset Crossings, like this one, reduced crashes and made cyclists more comfortable.
“[A]s overall traffic fatalities have declined and cycling has increased within New York City under Vision Zero, the number of cyclists lost in fatal crashes has remained stubbornly and tragically high, with deaths actually increasing over the last several years,” DOT commissioner Polly Trottenberg wrote in the study’s introduction. “With the goal of reversing that trend, DOT has taken a closer look at cyclist safety. And specifically, because 89 percent of crashes occur within intersections, our Transportation Planning and Management team was charged with doing a clear-eyed analysis of how we could further improve intersections to keep cyclists safe, especially as vehicles turn.”
The study focused on four intersection types on one-way streets with protected cycling infrastructure, like parked cars, bollards, or barriers buffering bikes from traffic.
A current generation Mixing Zone intersection joins cars and bikes in the same lane.
Two of the designs are already established in the city: the “Mixing Zone” intersection where bikes and turning vehicles share space—like a bike lane converging with a turning lane—and have been shown to reduce crashes by 27 percent. The “Fully Split Phase” intersection has separate traffic signals and lanes for bikes and cars; it reduced crashes by 54 percent. DOT recommends prioritizing this design for two-way streets with wider intersections.
DOT piloted two new designs for the study, which focused on Manhattan. In the “Delayed Turn” intersection, vehicles and bikes share a Mixing Zone-like lane but bicycles get a head start with the signal. The “Offset Crossing” or protected intersection, which riffs on Dutch cycling infrastructure, separates bicycles and turning vehicles with things like pedestrian crossing islands, flexible bollards, and contrasting paint on the pavement.
A Fully Split Phase intersection gives cyclists and vehicles separate lanes and signals.
“Not everybody bikes, drives, or walks in the same way, so each street needs a context-specific solution,” says DOT spokesperson Brian Zumhagen. “The findings help refine the most appropriate street and traffic conditions for these designs.”
The study concluded that Mixing Zone and Fully Split Phase intersections have substantial bike crash reductions following installation. It also found that Delayed Turn and Offset Crossing intersections make cyclists feel comfortable and reduce conflicts with vehicles, like crashes and right of way confusion.
The Delayed Turn intersection gives bikes a few seconds head start on green lights.
DOT plans to build more offset crossings—which are fairly new to North America but established in Europe—as a result of the study. Ninety-three percent of bicyclists surveyed reported feeling safe riding through Offset Crossing intersections compared to just 65 percent in Mixing Zones.
Cities like San Francisco, Seattle, Chicago, Washington, D.C., and Vancouver have been experimenting with variations on protected intersections, but New York is among the first to examine how to codify and scale them citywide.
DOT’s study includes a decision-making matrix for what intersection design is most applicable, depending on traffic characteristics.
Moving forward, DOT plans to update Mixing Zone streets to have shorter zones, install more left-turn traffic calming measures, update signals to improve bicycle flow at intersections, and install more visibility markings at intersections. It also plans to continue more pilot treatments.
“Creating streets with treatments such as Protected Bike Lanes that reduce crashes andreduce the risk of severe injury when crashes do occur—e.g., slower speeds, visibility, predictable behaviors—is critical for achieving Vision Zero,” says Zumhagen.
This Mixing Zone is located on the Upper West Side of Manhattan.
These interventions can’t come sooner or more prolifically enough. DOT is prioritizing redesigns of 20 key intersections in the city—but considering there are thousands of intersections in New York, this number is scant compared to the overall street network. Pedestrians and cyclists deserve to feel safe and actually be safe on every street and at every intersection.
I ride regularly in New York—though mostly in Brooklyn—and have experienced many of the interventions in the study: the Offset Crossings, signals that give me a couple seconds lead over cars, curb bump outs, and so on. While these are all promising, the problem of too many cars driving too fast with little regard remains. Even on sidewalks, we aren’t safe. Looking at the flattened plastic bollards that are supposed to protect cyclists and pedestrians, it’s clear that drivers will disregard anything that won’t scratch their paint or cause wheel or axle misalignment. What’s needed now are more traffic-calming measures and more enforcement to ensure bike infrastructure is used for its intended purpose. What good will they do if drivers flat out ignore them?