New York City will begin adding side guards to 240 of its medium-duty trucks that will prevent a pedestrian or cyclist from being caught under a vehicle during a collision, Mayor Bill de Blasio has announced.

The initiative, which is part of the city's Vision Zero program, will initially bring side guards to 18 trucks; the city will retrofit the remaining 222 by the end of the year. The city operates a fleet of more than 27,000 vehicles.

"When we change the way we do business like this, it changes our streets for the better," said Stacey Cumberbatch, commissioner of the Department of Citywide Administrative Services. "DCAS is working in partnership with City agencies to improve safety for the public and our drivers including installing these life-saving side guards."

The city moved forward with the installation of the side guards after cyclist Hoyt Jacobs — a 36-year-old poet and Queens College adjunct professor — was struck and killed in Long Island City by a sanitation truck Jan. 17, said Council Member Ydanis Rodriguez.

"Last month, in response to the first cyclist death of 2015, I called upon our Mayor to install side guards on the City truck fleet in order to end these preventable accidents," Rodriguez said.

The guards cost about $3,000 each to purchase and install.

"Side guards have a proven record of preventing fatalities and injuries on the road and are a worthy investment of tax-payer dollars," said Council Member Julissa Ferreras, who chairs the finance committee.

The department began studying whether to install the guards in May, when it began a partnership with the Volpe Center at the U.S. Department of Transportation. The research included a review of international standards for side-guard use and exemptions, according to a city release. Volpe Center officials reviewed each city department's specific equipment, and issued a final report identifying 4,734 trucks eligible for the side guards. Trucks with a gross vehicle weight under 10,000 pounds were exempted.

As part of Vision Zero, DCAS has been tracking and analyzing collisions involving city vehicles. The city has expanded its defensive driving training and has installed telematics systems on city vehicles to better monitor driving behavior.