Transportation Alternatives says the de Blasio administration’s failure to fully fund Vision Zero street improvements is limiting the number of split-phase traffic signals DOT can install to prevent collisions at dangerous intersections.

In June, 30-year-old cyclist Olga Cook was killed by an allegedly drunk driver who made a right turn across the Hudson River Greenway at Chambers Street, one of several spots where motor vehicle traffic is allowed to encroach on one of the busiest bike routes in the United States. Crashes at these conflict points are common, often resulting in injury and death for cyclists who use the greenway.

In a statement released today, TA Executive Director Paul White says Cook’s death could have been prevented with split-phase signals at Chambers and West streets, to prevent turning drivers and greenway cyclists traveling straight ahead from entering the intersection at the same time.

The same principle applies to designing safe intersections for pedestrians. Nearly a third of pedestrian and cyclist deaths in NYC are caused by turning drivers who fail to yield, according to TA.

“Shared-phase traffic lights do not work,” said White, “just as shared lanes for drivers and people on bikes do not work.”

Data from street redesigns with protected bike lanes — where some intersections features split-phase signals and others do not — indicates that total crashes resulting in injury decline twice as much at intersections with split phases.

After Cook’s death, DOT told the Tribeca Tribune the agency is “studying the area for safety enhancement, including a right turn lane and signal phasing upgrades.”

White points out there are hundreds of intersections across the city that need safety upgrades, but those fixes won’t happen on the timetable prescribed by Vision Zero because Mayor de Blasio denied the City Council’s request to boost the DOT budget for street improvements. The most recent city budget also cut funding for DOT Traffic Operations staff by 2 percent, according to TA.

White called on the mayor to fully fund necessary street and intersection redesigns, and to stop putting the lives of people who walk and bike in the hands of mercurial community boards.

People should not be allowed to die on streets that City Hall knows are dangerous. In order to prevent the next story of a New Yorker mowed down while walking to the store or biking to work, Mayor de Blasio must fully fund a priority engineering analysis of New York’s major streets and dramatically increase the DOT’s capacity to fix hundreds of dangerous intersections across the city.

In general, New York City needs to get to the place where proven street safety improvements like protected bike lanes and split-phase traffic signals are treated as vital public works. Instead of being bounced around as political footballs, these street safety redesigns should be non-negotiable, in the way that, for example, improvements to guarantee safe drinking water are non-negotiable. City Hall must put Vision Zero street safety fixes on a different political footing by funding and implementing them, instead of giving unelected and unrepresentative community boards veto power over these lifesaving projects.