NYC Plaza Program — Times Square and Broadway Street-to-Plaza Conversions (2009–)

From 2009 NYC DOT converted stretches of Broadway, including Times Square and Herald Square, into pedestrian plazas under its Green Light for Midtown initiative, using temporary surface treatments and movable furniture, and collecting data to justify permanent change. The wider NYC Plaza Program invites local nonprofit partners to apply, who then manage and maintain plazas, and prioritises areas lacking open space, especially high-pedestrian or low-income neighbourhoods; 71 plazas were in some phase of planning, design, construction or completion and 49 were open by 2015.
Reported results on the Broadway corridor (about 2.3 miles) include 63% fewer motorist and passenger injuries and 35% fewer pedestrian injuries, 11% more pedestrians in Times Square and 6% in Herald Square, a 17% northbound travel-time improvement in West Midtown, vehicles exceeding 30 mph on one block falling from 28% to 12%, and weekday and weekend cycling up 16% and 33%. In surveys, 74% of respondents approved, 20% of business owners reported improved conditions and none reported adverse effects.
Caveats: results are largely NYC DOT's own pre/post analysis rather than independent evaluation, retail claims in secondary summaries are weakly evidenced, and plazas depend on nonprofit partners' ability to fund maintenance. It is a widely copied example of low-cost, data-led interim street redesign.

Read the full analysis: https://www.pps.org/article/broadway-boulevard-transforming-manhattans-most-famous-street-to-improve-mobility-increase-safety-and-enhance-economic-vitality