NY Times

"You continue to advise your members to stop at red lights," Mr. Scoppetta wrote, "regardless of whether it is necessary or sensible to do so. This has resulted in an increase in response times well beyond those caused by our successful effort to reduce accidents."

Capt. Peter L. Gorman, the president of the Uniformed Fire Officers Association, which represents 2,500 fire officers, said the letter was an effort to deflect attention from the city's role in slower responses, including its closing of six engine companies in 2003. The unions have long maintained that the closings would delay responses in those neighborhoods and reduce the number of overall companies available to respond to calls. The city says the allegation has been debunked by its statistical analysis.

Mr. Gorman acknowledged advising his members to proceed more carefully to fires, but only out of a concern for safety. He said his advice might have contributed to the higher response times "in some ways."

"We race each other to boxes," Mr. Gorman said. "Our members are so focused on getting to an alarm, so we've been telling them to make sure they get there safely."

He said it was disingenuous to blame the unions for slower driving when the department has begun installing cameras on fire trucks to monitor how safely they are driven. "Response times have gone up because Big Brother is watching them," he said. Stephen J. Cassidy, president of the Uniformed Firefighters Association, said the city has been hammering away on unsafe driving and is ultimately responsible for the consequences.

"It seems like they have accomplished what they set out to accomplish," he said. "They should be patting themselves on the back."

Fire companies are also being delayed, Mr. Cassidy said, because the department has been closing more firehouses each day while companies go for training or medical exams, a practice that expands the coverage area for the others. Fire officials denied that there had been any change in the volume of companies taken out of service for training or other duties.

The response time issue is the latest in a series of disputes that have pitted the fire unions and their members against the administration of Mayor Michael R. Bloomberg, who is running for re-election. Just weeks ago, firefighters cheered their chief of department, Peter E. Hayden, after he openly questioned the Bloomberg administration's new emergency response plan at a City Hall hearing.

Experts differ on how long it takes a fire to grow beyond control, but there is a national guideline on optimum response that sets a standard of six minutes or less.

"The criteria is four minutes travel time," said Gary Tokle, an assistant vice president at the National Fire Protection Association. That standard, written by a technical committee in 2001 and designed to confront fires while they are still small, anticipates a dispatch time, including 911 calls, of one minute, and an additional minute for firefighters to leave their quarters.

New York City firefighters have long taken pride in their quick response, according to Vincent Dunn, a retired New York chief. Though comparative studies that rank cities by average response time are rare, New York officials believe the department is in the top tier, experts said.

In 1990, the average response time rose to 4 minutes 50 seconds, but it fell over the next few years. It has been creeping up again since 2002, when the response time was 4 minutes 13 seconds. Even so, there has been little consequence in loss of life. The 82 fire deaths in New York last year were the lowest in 80 years.

The fire truck involved in last July's accident was responding to a fire in a 16-story Bronx building when it sped through a red light and struck a white Dodge Durango, killing Ronaldy Mendez, 26. Mr. Scoppetta described the driving as "reckless" in his letter. The department brought disciplinary charges against the driver from Engine Company 94 as well as his officer, but the penalties have not been decided yet.

Five months after that accident, Commissioner Scoppetta handed down what the unions described as a puzzling edict. Rather than tighten driving rules, he eased them, the union said. In place of a department regulation that required trucks to stop at red lights, he adopted state laws that allow emergency responders to roll through them with care. The Fire Department said the change simply formalized a longtime practice: fire trucks rarely stopped at red lights. Now, Mr. Scoppetta charged yesterday, Mr. Gorman has instructed his members to not just slow down, but stop, at lights and stop signs.

Mr. Gorman said he has instructed his members to follow the stricter, national guidelines that require stops at red lights, stop signs and blind intersections. He said he made the recommendation because the public would be safer, collisions would be reduced and because he has lost confidence that the department will stand behind drivers who get in accidents.

"There are two ways to reduce response times," said Lt. Michael Wilbur, a Bronx fire officer who trains Fire Department personnel in other states how to drive. "Either you put firehouses in strategic places, or people drive in an unsafe manner. You can't have it both ways."

Lieutenant Wilbur said he believed drivers in his firehouse, Ladder Company 27, were stopping more frequently at intersections. "As a driver, you're stuck between a rock and a hard place. You're a blue-collar working stiff, making $50,000 a year," he said. "If you get sued, you may not know if you have a house in five years."

Fire officials said firefighters in accidents have always been represented by city lawyers, including the driver in the July accident, who is being sued by the victim's mother.