Even when she has a walk signal, Jane Pachuta has been cut off by cars making left turns and barreling through the crosswalk near her home on the Upper East Side of Manhattan.

“Numerous times, I’ve felt in danger,” said Ms. Pachuta, the owner of an advertising and graphic design business who has lived in the neighborhood for more than two decades. “I walk relatively quickly, but it doesn’t matter when they’re turning and getting so close to you.”

But now Ms. Pachuta has a head start. The walk signal at the crosswalk on Third Avenue and East 70th Street was recently re-timed to come on seven seconds before drivers get a green light — instead of at the same time — so pedestrians can get well across Third Avenue before the cars can move.

On New York’s increasingly crowded streets, so-called “pedestrian head starts” have become a key tactic used by city officials to reduce dangers at busy intersections by making pedestrians more visible and reinforcing their right of way. While the concept is not new, the pedestrian measure has quietly multiplied across New York City as part of an ambitious campaign — known as Vision Zero — by Mayor Bill de Blasio that aims to eliminate traffic deaths by 2024.