May 16 2014

As Bike to Work week continues, New Yorkers got some good news from a team of researchers at Columbia University’s Mailman School of Public Health. Using funds from the federally funded Safe Routes to School program enacted in 2005 in an effort to create safe environments for American children to walk or bike to school, New York City made safety changes to the most dangerous intersections near schools. These interventions included narrowing intersections by building out sidewalks, setting off dedicated bicycle lanes, and installing speed humps, and timing lights so pedestrians have more time to cross. The program, which was de-funded last year by Congress, cost $10 million but will bring about an overall net societal benefit of  $230 million (in 2013 value) saved and 2,055 quality-adjusted life years gained in New York City, according to the study. 

Findings are in the May 15 online edition of the American Journal of Public Health

Streetcross80613727sm.pngThe estimates were obtained using data from the injuries that were already prevented by the safety changes made to over 100 public schools during the latter half of the Bloomberg administration under the Department of Transportation Commissioner, Janette Sadik-Khan. The authors assumed that the safety benefit conferred by these environmental changes would persist for about 50 years—the usual life of infrastructure in New York City. Not included were important sources of savings, such as reduced use of government disability programs, so the savings could be higher. While the study did not use the standard method of evaluation—randomized controlled trials—it did use much more powerful statistical techniques than are often employed in such studies. This was made possible because the authors had data on intersections before, during, and after modifications were made.

“Our study provided compelling evidence that the Safe Routes to School program has made a marked difference in improving the safety of school-age children in New York City,” said Peter A. Muennig, MD, MPH, Mailman School associate professor of Health Policy and Management, and first author of the study.
 
The research was supported by the National Center for Injury Prevention and Control, Centers for Disease Control and Prevention (grants 1 R21 CE001816 and 1 R49 CE002096); the National Institute on Drug Abuse, National Institutes of Health (grant DA029670), and the Center for Injury Epidemiology and Prevention, Columbia University. The authors declare no conflict of interests.

Co-authors are Drs. Guohua Li and Charles DiMaggio of the Mailman School of Public Health and the Center for Injury Epidemiology and Prevention, and doctoral student, Mike Epstein of the Mailman School of Public Health.