Press Releases

Press Release #10-013

NYC DOT Releases Sustainable Streets Index, Using Valuable New Data For Traffic Management

Taxi GPS data helps identify daily network-wide traffic trends in Manhattan for the first time

New York City Department of Transportation (DOT) Commissioner Janette Sadik-Khan today issued the Sustainable Streets Index (SSI), a comprehensive report that monitors a range of key traffic indicators across the city and also evaluates the safety and mobility impacts of 12 DOT projects citywide. An important feature of this year's report is a day-by-day calendar indicating the average daily speed of traffic in Manhattan's Central Business District (CBD), giving traffic planners a revealing snapshot of how well traffic was moving on a given day. The report also tracks a dozen project indicators in all five boroughs, detailing the effectiveness of a variety of DOT traffic engineering, traffic signal, regulatory and pricing solutions in improving safety, enhancing mobility and expanding transportation options. Importantly, the report case studies show progress in the City's efforts to improve mobility in all five boroughs. Simplifying a complex traffic pattern at the Bronx Hub yielded significant safety gains, new public space and a 10% increase in the number of vehicles able to pass through that intersection, one of the borough's busiest. At Tillary and Adams Street in Brooklyn, traffic signal re-timings and turn restrictions reduced vehicle delays by 45% at the foot of the Brooklyn Bridge. Taken together, the SSI will help the agency identify trends so it can better tailor safety and mobility initiatives citywide.

"We're bringing new tools to measure the impact of the changes we're making on our streets," said Commissioner Sadik-Khan. "These new metrics give us a microscopic view of blockages in the city's traffic flow, helping us build safer, more sustainable streets for New Yorkers."

The travel speeds for the CBD, culled from comprehensive taxi GPS data at a rate of approximately 13 million individual taxi trips per month, found that traffic on Aug. 19 was one of the 25 slowest days of 2009, with an average speed of 8.7 m.p.h.—likely influenced by the heavy rains and severe winds that swept across the city that day combined closure of the northbound FDR Drive for road repairs. Monday, Sept. 28 was the fastest non-weekend or holiday traffic day of the year, with an average speed of 11.7 m.p.h. in the CBD.

Developed in accordance with Local Law 23 and submitted to the City Council, the data and indicators also demonstrate the City's progress toward a safer and more sustainable transportation network that is withstanding the current recession, positioning the city to accommodate renewed job growth and enhance New Yorkers' quality of life as the economy recovers.

Many results, coming as the city entered the current recession, continue the shift toward sustainable modes of transportation that was seen during the preceding years of economic growth. The continued growth of transit ridership and cycling, even as traffic volumes declined, indicates that the shift toward sustainable modes is not dependent on economic growth. Instead, this shift has been produced by the long-term investment in the transit infrastructure and rapid expansion of the bicycle network, both of which have attracted growing numbers of New Yorkers during the start of the recession as well as the earlier period.

Using taxi GPS data, the report found that traffic speeds in the CBD had improved 13% from fall 2007 compared to fall 2009, likely the result of economic factors.

Other key findings for traffic and transit trends are:

  • Citywide traffic volumes declined 2% in 2008, and a total of 3.4% since 2003.
  • Traffic entering Manhattan's CBD dropped 3.7% in 2008 and is down 6.9% since 2003.
  • Citywide bus and subway ridership increased 3.2% in 2008, for a total increase of 12.3% since 2003.
  • Cycling volumes into the Manhattan core increased 32% in 2008 and 26% in 2009, and have more than doubled since 2003.
  • Daytime traffic speeds in the Manhattan CBD increased by 8% from fall 2007 to fall 2008, and an additional 4% from fall 2008 to fall 2009.
  • Between 8 a.m. and 6 p.m., Manhattan CBD traffic averaged 9.1 m.p.h. in the 12 months ending in October 2009.

As part of this report, the DOT tracked 12 major projects that were implemented by the end of 2008 to reflect the multimodal character of the agency's projects.

Key highlights from the project performance indicators are:

  • 77% reduction in total crashes involving injuries at Park Avenue and E. 33rd Street from changes made to traffic patterns in the area.
  • 45% reduction in vehicle delays at the Tillary and Adams Streets approach to the Brooklyn Bridge, from signal retimings and turn restrictions.
  • 32% increase in ridership on the Fordham Road Select Bus Service (SBS) bus.
  • 19% increase in bus speeds on Fordham Road in the Bronx and 17% increase on 34th Street in Manhattan from the SBS program. The typical commuter on Fordham Road gains two days annually from the time savings.
  • 18% reduction in average traffic speeds between 9 a.m. and noon along Skillman and 43rd Avenues in Sunnyside, Queens.
  • 16% improvement in bus travel times along Victory Blvd. on Staten Island.
  • Six percentage point improvement in weekday parking availability from the Greenwich Village PARK Smart pilot program.
  • Five-fold increase in cycling on the new Jewel Avenue bike lane in Queens.
  • 15,000 sq. ft. of new pedestrian plaza and bicycle lanes in the Bronx Hub.

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