The warnings first appear just south of the checkpoint here and continue almost as far north as the San Onofre nuclear power plant. Well known by now, they depict the silhouette of a man, woman and child dashing east to west across a yellow background.
The drawing symbolizes the real people who make the grim run for their lives across Interstate 5 as they try to elude the U.S. Border Patrol.
Until last August, when a seven-mile-long, eight-foot-high fence was erected in the median strip from Las Pulgas Road in Camp Pendleton to the edge of the checkpoint, the warnings went largely unheeded--both by fleeing illegal immigrants and streams of speeding motorists, authorities say.
But now the U.S. Border Patrol and the California Highway Patrol say the $458,000 fence has begun to have an impact. No pedestrian fatalities or injuries have occurred along an 18-mile stretch, which encompasses Camp Pendleton property just north of Oceanside to the checkpoint--located three miles south of San Clemente--since March 14, 1993.
The fence, however, is hardly viewed as a panacea. More than a year of good luck has also been a factor, said Karl Hansen, spokesman for the CHP, which documents pedestrian fatalities near the checkpoint. Hansen and others also attribute the fluctuating number of deaths to a series of random factors.
The CHP and the Border Patrol "tend to celebrate anything that's had a positive impact," he said, "which the fence certainly has. But it's not the foolproof answer. Next week, we could have five or six people hit. We hope and pray it continues to work. But the problem remains."
"What was so different in 1991 when we only had two fatalities, as compared to 1990, when we had 15--our worst year ever?" Hansen asked. "Luck does have a certain amount to do with it."
At the same time, Hansen and others credit an aggressive public relations campaign carried out by the CHP's Mexican liaison office for having spread the word about the dangers of Southland freeways to the migrant labor camps of San Diego and Orange counties and the rural communities of northern Baja California.
Statistics bear out the random nature of the problem--four fatalities in 1993, before the fence was completed in August; seven in 1992; two in 1991; 15 in 1990; 14 in 1989; six in 1988, and five in 1987, according to the CHP.
In an effort to control the problem, the CHP in 1992 received a federal grant to station three more officers along the 18-mile stretch, but in that year alone, seven illegal immigrants were struck and killed.
By the end of the year, the funding was cut. And before the fence could be completed last August, four fatalities had occurred, along with one serious injury.
Pedestrian fatalities near the checkpoint have long had an impact on hospitals in south Orange County, which ended up with scores of trauma cases the severity of which doctors rarely see.
Dr. Thomas Shaver, director of trauma services at Mission Hospital Regional Medical Center in Mission Viejo--where many of the victims were treated--has been an outspoken critic of the federal government for, in his words, helping to create the problem.
Shaver favors an El Paso-like blockade at the San Ysidro port of entry, under which all available agents would be deployed at the international border. Under that plan, any would-be immigrants who somehow make it across would be ignored.
Such a blockade could spell the end of the San Clemente checkpoint, which Shaver sees as playing a fatal role in most of the incidents involving pedestrians.
"My whole point is, why create a dangerous obstacle 66 miles" from the border? he said.
Shaver noted that the average cost of treating one patient admitted to a trauma center is $22,000. Should a severe head injury result, he said, the average cost per person jumps to $250,000. Long-term rehabilitation sends the cost even higher.
Because most of the patients are uninsured, the cost is borne entirely by taxpayers.
An 8-year-old Mexican boy died in 1990 in a scene that bears an uncanny resemblance to that depicted on the signs: Clutching his mother's coat, he was struck by a car while trying to cross the freeway in the southbound lanes.
"When you get these patients, they are so violently injured because of the impact that, you work hard, but the outcome . . . is never satisfactory," he said. "It will never make them physically or mentally whole, nor will they ever be gainfully employed."
But Shaver praised the fence for creating at least a stopgap deterrent.
"If a fence can help stop that," he added, "it has to be viewed as a step in the right direction. If it's helped to stop the loss of life, I'm all for it."
In the eyes of authorities, the fence appears to have halted, however temporarily, what extra personnel and flashing warning signs could not. The wire barrier is applauded by state and federal officials, who have no intention of closing the checkpoint.
"We see the fence as having a dramatic impact," said G.C. Geer, the agent in charge of the San Clemente Border Patrol Station. "But other factors have helped too. Warning signs went in (1991), and Caltrans started stripping away vegetation in the median" in 1992.
That was the same year the CHP launched a speed-reduction campaign that the agency believes has also helped cut down on fatalities.
Still, no measure has eliminated illegal immigration near the checkpoint. Geer said that more than 50,000 illegal immigrants were apprehended there in 1993.
The U.S. government has appropriated $30 million for the first phase of a new 16-lane freeway checkpoint proposed for the Horno Canyon area, next to the Camp Pendleton Marine Corps Base. The checkpoint would have 16 electronic gates for traffic flow, added truck scales and booths for Border Patrol agents, who now stand unprotected on Interstate 5.
But the new checkpoint is not expected to open for at least another decade.
In the meantime, statistics support the notion that the fence is having a continued impact. So far this year, not a single fatality or injury has been reported anywhere between Las Pulgas Road and the Orange County border.
"We argued from the very start that if you could keep (pedestrians) out of the southbound lanes, which is where the problem is, you could cut down drastically on the problem," Geer said.
"People in the northbound lanes are more accustomed to seeing the signs and slowing down, and of course, the checkpoint operates only in the northbound lanes," Geer said. "Drivers in the southbound lanes know they don't have to stop."
The average speed of drivers in both directions in the area near the checkpoint is more than 70 m.p.h. at most times of the day or night, CHP officials said.
Geer estimates that 90% of those trying to head north--illegal immigrants, drug smugglers or anyone else attempting to traverse the dark stretches of Interstate 5--are now staying east of the freeway, reducing even the potential for harm.