As traffic engineers simplified the grid by forcing traffic in one direction or by eliminating turns across oncoming traffic, Broadway remained an outlier. As the diagonal street crossed the major avenues, the convergence of three lines of traffic greatly encumbered on the capacity that had been built into the grid through signal timing. While the rest of the island moved on a simple two-phase system, the bowties, or triangular sections (especially at Times Square and Herald Square) necessitated the addition of a third, throwing off the progression of green lights to be followed up and down the island.
In addition, these crossings occurred at two of the busiest pedestrian points in the city. Crowds were being pushed from the sidewalk into the roadbeds, places that also had come to include pedestrian refuges, further encroaching into the space needed for proper traffic flow. Under the leadership of Janette Sadik-Khan, the Department of Transportation daringly did what traffic engineers had wanted to for years: she reasserted the grid.
Initially enacted as a pilot program in 2009, cars coming down Broadway were redirected to Seventh Avenue. Five blocks of roadbed at Times Square and three at Herald Square were converted into pedestrian plazas to accommodate the hoards of office workers, tourists, and shoppers. While there had been hopes that traffic would actually move faster after removing Broadway from the system, analysis showed that in fact there was almost no change despite the reduced amount of roadway. Decreases in pedestrian, motor vehicle, and bicycle accidents, however, led Mayor Michael Bloomberg to declare the changes permanent in 2010. JR