The number of District intersections deemed particularly dangerous by traffic engineers nearly doubled last year, a new study shows.

The city-funded analysis found that 330 intersections had at least 10 crashes, up from 176 in 2003.

D.C. traffic engineers could not explain the spike but said it might be the result of a slight increase in the number of cars traveling certain roads. They said they will launch an initiative in coming months to install electronic sensors at each traffic light in the city to better regulate the traffic flow and improve safety.

The $40,000 study, conducted by the Michael Baker Corp., examined crashes from 2002 to 2004.

It found that high-crash intersections accounted for 30 percent of the city's 18,262 collisions last year, an increase from 15 percent in 2003.

The crash-prone locations were concentrated along busy commuter routes. Among the worst: New York Avenue.

Designated a "high-crash corridor" in the study, New York Avenue in 2004 accounted for five of the top 10 crash sites, including the most crash-prone intersection: New York Avenue at Bladensburg Road NE. That intersection was the site of 71 wrecks and 40 injuries last year.

Police officials and engineers blamed the high number of accidents on the traffic volume flowing along New York Avenue toward Maryland and into the District.

Even when engineers consider other factors, including the amount of traffic, the severity of the wrecks and their financial cost, New York at Bladensburg ranks as the worst in the city, according to a separate analysis by city engineers.

City officials estimated that crashes at the intersection cost nearly $8 million in property damage, medical fees and legal claims over a three-year period.

Motorists said they were not surprised that the intersection was so dangerous.

Jerald Katz's new Toyota Avalon was rear-ended in a three-car wreck at the intersection in May of last year. Katz and his wife weren't injured, but they had to pay $1,000 to fix the car's bumper.

"The biggest problem is that you have people doing 50 or 60 miles per hour, and they are entering an area where you are lucky if you can go 20 miles per hour," said Katz, 67, who lives in the Baltimore suburbs. "I think a lot of people just don't pay attention."

In coming months, city officials are planning to re-pave the intersection, improve pavement markings, add road signs and adjust the lights' timing, said Douglas Noble, chief traffic engineer for the D.C. Department of Transportation.

Officials are also examining longer-term solutions that could include bridges at New York Avenue and Bladensburg Road, as well as at New York and Florida avenues NE, Noble said.

He said the city has embarked on a project that is expected to provide substantial benefits within the next few years: a $10 million effort to install computers and electronic sensors at each traffic light.

The computers will operate individual traffic signals when they sense a car. The lights now operate on timers.

The sensors are intended to make it easier to regulate traffic and reduce the number of cars speeding through improperly timed lights. Noble said the sensors will be particularly helpful on busy streets such as Florida Avenue, another high-crash corridor.

Florida Avenue is relatively narrow, and that makes it difficult to conduct police enforcement without creating traffic bottlenecks, Noble said.

Officials said the sensors will be installed at the city's 1,560 intersections with traffic lights within the next several years.

"Traffic changes day to day and hour to hour," Noble said. "This establishes a better mechanism to match the flow of traffic to what the speed limits are."

Critics, including the area's largest motor club, support some of the city's efforts to reduce crashes but said officials have not acted quickly enough. They said city officials should have taken action on the trouble spots long ago, adding that the list of the worst intersections has varied little from year to year.

"It is very frustrating," said Lon Anderson, director of government affairs at AAA Mid-Atlantic. "Once they know where the crashes are, they need to do something about it."

The Baker study revealed another problem that engineers might not be able to solve: bad drivers. Inattentive motorists caused 15 percent of crashes.

"There is definitely a problem in terms of drivers in D.C.," said Ali Abdelfattah, who helped conduct the study. "They need to do more educational programs than anything else."

The Baker report recommended that the city improve lighting and road signs at intersections, change the timing of traffic lights and limit parking near intersections. The study also urged police to increase enforcement efforts in some areas to reduce speeding and reckless driving.

Police officials said conducting speed enforcement often is difficult because roads are so busy and have small shoulders.

To operate a speed checkpoint on many of the busiest routes, officers would have to park in the street and partially close a lane.

"That would cause gridlock," D.C. police Inspector Patrick Burke said. "There is no practical way to do enforcement at those intersections."

Burke and other police officials have been strong advocates for red-light cameras and photo-radar devices, which take pictures of violators. The devices have generated hundreds of thousands of tickets, which are mailed to motorists.

Among the study's other findings:

* Although crashes that caused injuries increased by 15 percent last year, fatalities dropped from 69 in 2003 to 45.

* About half of the traffic deaths were caused by speeding.

* About 60 percent of the crashes occurred in daylight, and 8 in 10 occurred in clear weather.

* At the city's 25 most crash-prone intersections, rear-end collisions were responsible for one-third of the 2,580 wrecks during the study's three-year period. Sideswipe crashes accounted for 22 percent and right-angle accidents for 15 percent.

* About 30 percent of crashes occurred during the rush hours -- between 7 and 9 a.m. and 4 and 7 p.m.

* More than 660 pedestrians were injured, including 10 who were killed, in 2004. Pedestrians were at fault in 36 percent of the 681 crashes involving pedestrians.

"You do see an awful lot of people walking against the lights in this city," Noble said. "They are not in crosswalks in the middle of the block."

Vehicles pass through on a yellow light at New York Avenue and Bladensburg Road NE, the site of 71 accidents in 2004, the most in the city.A wreck at the intersection. Officials are planning to re-pave the intersection, improve pavement markings, add road signs and adjust the lights' timing.Crashes at this intersection cost about $8 million in property damage, medical fees and legal claims over a three-year period.Douglas Noble, the District's chief traffic engineer, said sensors that are scheduled to be installed in coming years at the city's 1,560 intersections with traffic lights will establish "a better mechanism to match the flow of traffic to what the speed limits are."