Standing a safe distance back from the traffic rolling down Ocean Parkway in Brooklyn, Betty Smith, cane in hand, waited at noon on Monday for the Beverley Road light to change. She was discussing the speed limit on the parkway, which a state senator wants to boost to 30 miles per hour from the current 25. “I think the traffic moves pretty well now,” she said. Just then, like a log hurtling down a flume, the wheels of a car skirting the curb picked up a puddle of slush-melt and sent it jetting toward Ms. Smith. She took a step back and finished her thought.

“So,” Ms. Smith said. “I don’t think it needs to be raised.”

Ocean Parkway runs about five miles, from Prospect Park to Brighton Beach. With its six lanes and tree-lined medians, it is one of the great boulevards of the United States. It has also ranked among the city’s most dangerous — “one of the highest crash and fatality rates in Brooklyn,” Polly Trottenberg, the commissioner of the city’s Department of Transportation, said.

Along the very stretch of road where Betty Smith stood, someone had driven over the speed limit every six seconds during the week of March 5th to 11th, according to readings taken by city cameras. That’s about 91,000 drivers.

On average, though, fewer than 1.1 percent of speeders on the parkway receive tickets sent by the automated system, because of limitations that include the hours that the cameras can issue them (during the school day), a state law that permits fines only for those caught going 11 miles per hour or more over the limit (speeds of 26 to 35 are illegal but not enforced by the cameras) and, in some cases, technical difficulties in identifying the license plate.