All were New Yorkers who lost their lives while biking in the city in 2019.

At least 28 cyclists died in New York City last year. That’s the highest number in two decades, according to year-end statistics from Mayor de Blasio’s administration.

Overall traffic deaths — including cyclists, pedestrians, motorcyclists and those traveling in motor vehicles — were also up for the first time in years.

[More people are dying on New York City’s streets. What went wrong?]

Here’s what we know about the problem.

There were 219 traffic deaths last year, up from 203 deaths in 2018 — a wave of vehicular violence that has raised doubts about Mr. de Blasio’s plans to improve safety.

Mr. de Blasio’s plan, known as Vision Zero and modeled after a Swedish proposal, had been showing promising results. Traffic deaths dropped to their lowest level in a century in 2018.

His administration blamed reckless behavior by drivers and more collisions involving large vehicles like trucks and sport-utility vehicles for the increase in deaths.

There was another pedestrian death on New Year’s Day. A 74-year-old woman was killed by an S.U.V. as she crossed a street in Queens.

Mr. de Blasio’s administration said it would move aggressively this year to install more protected bike lanes and cameras to catch speeding drivers.

Biking has become increasingly popular in New York City in recent years, with nearly 500,000 bike trips each day.

But another popular gadget — the shared electric scooter — is not coming to the city as some had hoped. Governor Cuomo recently vetoed a bill to allow the scooters.