U.S. Acts to Keep Migrants From Freeways : Fatalities: New Border Patrol strategies aim to cut off their access and reduce injuries, from Mexico to Orange County.

The U.S. Border Patrol, attempting to reduce the number of illegal aliens struck and killed on San Diego County freeways, has launched a series of strategies aimed at preventing migrants from reaching Interstate 5 and other area highways, from the Mexican border to Orange County.

Gustavo de la Vina, chief Border Patrol official in San Diego, said the new schemes call for cutting off aliens’ access to freeways in the border zone--particularly near Dairy Mart Road in San Ysidro--along a major migratory route.

In addition, De la Vina said, the agency has begun posting undercover agents in two major smuggling staging areas--San Ysidro Boulevard, which adjoins I-5 in the border area, and the Aliso Creek rest area, south of the San Onofre Border Patrol checkpoint along I-5 in Camp Pendleton.

The idea, he said, is to disrupt smuggling patterns, thus reducing the incentive for people to negotiate the freeways on foot in the hope of finding rides north.

“We just don’t want to see the aliens on the freeways,” De la Vina said Wednesday. “It’s creating a hazard for our officers, for the traveling public, and for the aliens themselves. . . . We don’t want to see these tragic events happening.”

During the past four years, more than 100 migrants have been struck and killed by vehicles along freeways in the border strip and along I-5 near the San Onofre checkpoint. The death toll for 1990 alone stands at 28, including 16 victims in the border area and 12 in North County.

In the border zone, three almost converging highways--I-5, I-805 and California 905--form a high-speed barrier for migrants who have just crossed illicitly into the United States. Many gravitate to the freeways, seeking rides north and short-term protection from apprehensions by Border Patrol agents, who, for safety reasons, avoid arresting people along the highways.

Almost 70 miles to the north, many migrants attempt to evade inspection by walking around the Border Patrol checkpoint. The maneuver often requires several crossings of eight lanes of traffic.

Providing ideal cover, officials say, are the dense brush, tunnels, drainage canals, parking lots and other prospective hiding places along the freeways.

Last weekend, De la Vina said, authorities began posting additional agents between the border and the grid of roadways in the area, attempting to cut off freeway-bound migrants before they reached the busy arteries. The agents, transferred from other Border Patrol stations, were positioned to the west of I-5, near Dairy Mart Road.

“We’re looking for ways to shortcut them,” De la Vina said. “We’ve set up a series of secondary positions.”

The strategy is typical of the constantly evolving tactics used by U.S. immigration authorities seeking to discourage the daily arrival of thousands of illegal migrants. However, smugglers and their charges usually respond quickly to the enforcement efforts, devising alternate routes to counter the pressure.

On Sunday, said Ted Swofford, supervisory Border Patrol agent in San Diego, the bolstered crew assigned to the Dairy Mart Road area recorded 1,760 arrests along the approximately six-mile-long strip of border between the converging freeways and the ocean. That compares with an average of about 1,500 arrests a day for the entire sector, which includes all of San Diego County and parts of Orange and Riverside counties.

Near the San Onofre checkpoint, authorities said, the Border Patrol has bolstered undercover operations at the Aliso Creek rest area and increased visibility by assigning more of the agency’s green and white vehicles to cruise along I-5.

The hope, De la Vina said, is that the increase in roving patrols will cause motorists to slow down--the average vehicle speed in the area is 70 m.p.h., according to state officials--and also discourage migrants from crossing the freeway on foot. Border Patrol officials plan to install more warning lights near the checkpoint in an effort to slow traffic.

“We’re trying to create an awareness among the traveling public,” De la Vina said.

The California Department of Transportation has have embarked on a series of parallel steps, including increased lighting, reduction of freeway-area brush and the posting of signs alerting motorists and pedestrians of the hazards.