One year ago, the Bloomberg Administration announced a “test project” that would turn Broadway between 42nd and 47th Streets (Times Square) and from 33rd to 35th Streets (Herald Square) into pedestrian malls, with the goals of improving traffic flow and reducing pollution. Mayor Michael Bloomberg recently proclaimed the initiative a success and announced that it would be made permanent—despite its failure to deliver promised benefits. Proclaiming an experiment a success does not make it so.

According to the city’s own assessment—not shared with the public until after the announcement—the project had only a “mixed” impact on traffic flow. In fact, traffic jams persisted on many cross-town streets, and speeds actually slowed along Eighth and Ninth Avenues. And, the projected improvements in speed on Sixth and Seventh Avenues missed the mark by wide margins.

We have seen the city push so-called “green” projects that can’t live up to their billing before. Two years ago, the state legislature shot down the Administration’s congestion-pricing plan, recognizing that the plan’s benefits were being oversold. But, with the city and state in financial crisis, we would not be surprised to see this over-hyped plan raised again.

With more traffic experiments on deck, we will be wary of any “green“ sales pitches for traffic projects that can’t deliver the benefits they promise. And, before the city expands the pedestrian plazas they have unilaterally declared a success, they should make the changes necessary to actually improve traffic flow.