SAN FRANCISCO -- Pedestrians and vehicles have once again proven a dangerous combination on San Francisco's 19th Avenue, where this morning a 56-year-old woman was struck by a vehicle and sent to the hospital, according to police.

The accident occurred at 19th and Holloway avenues at about 5:30 a.m.

"The preliminary investigation shows she was in a crosswalk against the light," said police spokesman Dewayne Tully.

Tully said he did not know whether the woman was on her way to the nearby San Francisco State University, but noted that the hour was rather early for classes to be starting.

The woman may have been headed to or from a Muni streetcar stop located at the intersection where the crash occurred.

"There's a street car line that runs in the middle of the road," Tully said.

Tully said that although the woman suffered head injuries, her wounds did not appear to be serious.

The case was not a hit-and-run, according to Tully, who said he did not know what kind of car was involved or how fast it was traveling when the impact occurred.

The accident is still under investigation, but Tully said he does not believe alcohol was a factor in the crash. "There would have been an arrest if there was any obvious DUI," he said. "That does not seem to be the case."

Accidents like the one this morning are, unfortunately, not unusual, police say.

"Nineteenth Avenue has had a history of pedestrian-related accidents," Tully said.

Last Wednesday at about the same time of day, 95-year-old Vincent Del Rosario was struck and killed at 19th Avenue and Taraval Street.

Del Rosario was also walking against a red light, according to Capt. Ed Springer of the Police Department's Traffic Division.

"We're trying to get the word out to everybody that they should be more cautious when they're crossing (the street)," Springer said.

Springer said he would like to see adults follow the guidelines commonly taught to children: stop, look and listen before you step into the street.

"The same rules apply even when you're older," he said.

Numerous pedestrian-related accidents have occurred along 19th Avenue this year, and at least two people have died as a result, Springer said.

Del Rosario's death was the most recent and in May, 22-year-old Srijaya Dalton was killed by a hit-and-run driver at 19th Avenue and Quintara Street after leaving a graduation party.

"It's a high-volume traffic area, particularly in certain sections" including the area near Stonestown Galeria and SFSU, Springer said.

Also, he added, the high number of accidents in the area can be attributed in part to the fact that "It's a very long street."

Springer said there are more pedestrian-related traffic accidents in downtown San Francisco than on 19th Avenue, but collisions on the thoroughfare tend to be more serious due to faster-moving traffic. The speed limit on most of 19th Avenue is 35 mph.

Springer did not have statistics on 19th Avenue itself, but said that 46 traffic-related fatalities have occurred citywide so far this year, 22 of which were pedestrians.

That number is up from last year, which saw 32 traffic-related deaths, 18 of which were pedestrians.

Although San Francisco is not as large as some other cities, Springer said, it is "very congested."

"Geographically, we're very small, but we have a high concentration of both vehicles and pedestrians," he said.

Police have written about 3 percent more traffic citations this year than last year, including 7,325 red light tickets, 7,000 stop sign tickets, 3,600 speeding tickets, 1,200 pedestrian right-of-way tickets and 51,000 tickets for other traffic violations as of October, Springer said.

Officers are also cracking down on people driving without a license, who are often those responsible for hit-and-run accidents. Springer believes many drivers flee accident scenes because they fear getting caught for violations such as driving on a suspended license.

Springer said San Francisco police are having some success in stopping unlicensed drivers from getting behind the wheel.

"We're pulling these people and their cars off the road," he said.

Numerous neighborhood coalitions have been formed across the city to deal with traffic safety issues in certain communities, including the Excelsior Street Safe project in San Francisco's Excelsior District.

Project organizers say more than 550 pedestrians have been injured by vehicles in the neighborhood over the past 12 years. Residents' complaints focus on two main concerns: speeding drivers and dangerous intersections.

The Excelsior District Action Plan, drafted by the coalition, calls for the city to enforce neighborhood speed limits, repaint crosswalks and install overhead crosswalks at key intersections, among other safety measures.