COLUMN ONE : Feeling Unsafe at Any Speed : Driving phobia can keep even experienced motorists off the road. They fear anxiety attacks brought on by freeways, tunnels or rush-hour traffic.

Rose Deetra, an accomplished Hollywood film development executive, peered in the rearview mirror, spotted a white big rig bearing down on her and floored the gas pedal in terror.

Ordinarily, Deetra never gets near the San Diego Freeway. It so horrifies her that her heart pounds and her chest tightens. Panic sets in. This time, however, her therapist was in the passenger seat.

“Slow down!” commanded Gerald Tarlow as his patient leaned forward and hastily switched lanes, white knuckles clutching the steering wheel.

Deetra, 29, is an experienced driver with no history of mental illness. But six years ago, she was overcome with driving phobia, an overwhelming anxiety that can strike without warning, virtually paralyzing even longtime and competent drivers.

Driving phobics worry about having an anxiety attack while behind the wheel. They fear losing control, needing help and being unable to get it. In rush-hour traffic or driving the left-hand lane, they often feel trapped. Bridges, tunnels or just the distance between freeway exits can send them into a tailspin. For Deetra and others, the condition twists their lives, forcing them to avoid situations, including jobs, that entail driving or causing them to spend countless hours on small roads as they bypass nerve-racking highways and other faster routes.

At its worst, the phobia completely grounds drivers. At the least, they become the butt of jokes and the victim of motorists’ wrath in a fast-lane society that prizes the automobile.

In Deetra’s mind, each highway offers its own memento of battle, a spot where she wrestled overwhelming emotions. On Sepulveda Boulevard, there’s the narrow tunnel near the airport that she drove into and then backed out 400 feet, snarling traffic, because she could go no further.

At the southbound San Diego Freeway on-ramp near Wilshire Boulevard, she once sat in tears for 30 minutes and begged her therapist not to make her drive the freeway. On the northbound 405, the dip after the Mulholland Drive ramp sent her anxiety soaring. At dinner parties, she couldn’t enjoy the food or conversation because she worried about driving back in the dark. As she fell asleep at night, she dreamed she was driving off the edge of the road.

“It gets depressing; it’s like you are incapable of normal everyday life. You feel like a total idiot,” said Deetra, who asked that her real name not be used.

Only two of Deetra’s friends know her secret. Her boss, colleagues and secretary don’t have a clue that she has this problem. Like many driving phobics, she only experiences anxiety when she is alone in her car--not when she rides in buses or cabs.

Experts estimate that about 16 million, or 8% of the nation’s population, suffer a range of phobias such as fear of flying, speaking in public or heights. Of those, several million people have a phobia that interferes with their ability to drive, said Jerilyn Ross, a therapist and president of the Anxiety Disorders Assn. of America. More precise numbers are unavailable.

“Once someone has a panic attack driving on the freeway, the fear reinforces the fear and they can’t get on the freeway at all,” said David L. Fogelson, associate clinical professor of psychiatry at UCLA. “These patients can’t tolerate being in a situation where they feel they can’t escape easily.”

No one knows for certain why some people are stricken with driving phobia. Some are genetically prone to anxiety, experts say. Others say the condition can be brought on by the accumulation of stress or occasionally by an accident. Although it can strike at any age, it is mostly likely to first occur in one’s 20s, said Tarlow, an assistant clinical professor of psychiatry at UCLA and director of the Center for Anxiety Management.

“People with driving phobias tend to be all different styles of personality; they are often successful people--not people who are timid or scaredy-cats,” said psychologist S. Lloyd Williams, who specializes in driving phobias.

Southern California, with its highways known worldwide for traffic and freeway shootings, is one of the worst places for a driving phobic, experts say.

“L.A. is a special case--you have got to drive freeways to get around. It means people with driving phobias are more disabled than they would be in other places,” said Williams, an associate professor at Lehigh University.

Phobics resort to various techniques to get through the day. They carefully craft routes. They learn relaxation breathing methods. They develop their own secret weapons to help ward off panic or lessen its impact when it strikes. One driver taped a tranquilizer to the dashboard. Another put a teddy bear in the passenger seat when she drove alone.

Treatment often involves therapy--though not every therapist conducts sessions in cars--and sometimes prescription drugs. The majority of cases can be successfully treated, although symptoms sometimes return, Ross said. But fewer than one in four receive help--either because people are too embarrassed to seek aid or the condition is misdiagnosed, she said.

Experts say treatment often depends on patients confronting their fears and getting behind the wheel.

With his voice steady, therapist Tarlow seemed unflappable even as a client recently crossed five lanes of traffic. One patient used to close her eyes when she felt anxious behind the wheel. But that didn’t bother him as much as the patient who insisted on driving 40 m.p.h. on the freeway. “You’d get these trailer trucks six inches from the back of the car,” he said. “It scared the hell out of me. I certainly realized why she was feeling anxious--it made me anxious.”

Leo Gendernalik, 55, a real estate consultant in Northridge, first recognized his problem 22 years ago when his employer dispatched him to pick up a client, 15 miles from the office. But as Gendernalik drove, “I could feel this scary feeling building and building and building.”

He tried to distract himself. He turned on the radio and started looking around at the trees and houses. But the panic kept boiling up inside. He made a U-turn into a gas station, called his boss and said he was sick. Since then, the area that Gendernalik could drive gradually became smaller and smaller.

He would make up excuses about why he couldn’t drive to the store when his wife needed sugar. He never told his best friend about his phobia, so when they went places together, he’d claim to have a headache so his friend would drive.

When his favorite uncle died, Gendernalik couldn’t go to the funeral in Anaheim--and he hated himself for it. He couldn’t take his two kids to Disneyland. He couldn’t take his son fishing.

Gendernalik--who sought help--can now drive. But his son and daughter are grown and he believes he missed much of their childhood.

“I’d love to do that over,” he said, his eyes tearing. “When you don’t drive, it’s real easy to feel less than a person.”

Many such as Gendernalik feel too ashamed to explain to others why they can’t simply climb behind the wheel and go.

“Nobody is surprised if you are scared when you are on top of a tall building and leaning over the edge,” said Nancy Raber, 41, a recreation official in Maryland, whose phobia, at its worst, could trigger a panic attack with the mere sight of an interstate highway sign. “If you back off, it’s socially acceptable. But if you back off driving, people don’t understand. There seem to be acceptable and unacceptable phobias.

“Why couldn’t I be phobic about something simple like daddy longlegs (spider-like bugs)?”

Some patients--such as Raber--suffer only driving phobia. But others are also afflicted by agoraphobia--a fear of being in public places. Combined, the two pose a psychological one-two punch that sends many to retreat into their homes.

Virginia Foss, 40, a Chatsworth homemaker and mother, has not driven alone for 12 years. She can vividly recall her first panic attack 20 years ago, remembering the streets (the intersection of Parthenia Street and Balboa Boulevard) and the flood of emotions as she drove with her 6-week-old daughter to her pediatrician for a checkup.

“I had a classic panic attack--my heart was pounding, my palms were sweaty. I had the overall feeling that something horrible was happening--something that would ultimately mean death or insanity,” Foss said.

Her daughter’s pediatrician attributed the event to Foss being a tired young mother. But she remained terrified that it would happen again. Suppose her baby needed her and she was once again paralyzed with fear? Suppose it happened while she was hurtling down the freeway at 55 miles per hour?

Two months later, she had another anxiety attack behind the wheel.

Today, Foss, who also has agoraphobia, is determined to wrench herself free from her fears. She began therapy through telephone sessions because she cannot yet go to her therapist’s office. She has ventured out in her beat-up 1978 white Mercury Cougar, taking it for a spin around the block, driving down the alley behind her home.

Foss plans these drives with the care of a general preparing for battle. She packs a tranquilizer in her purse, though she hasn’t popped one in four months. She never gets behind the wheel without her sunglasses, even though she usually drives at dusk. She always makes sure she has a bottle of water. Checking her gear is part of the ritual that she hopes will ward off panic.

Before she turns the key in the ignition, she assesses her anxiety level, using an emotional Richter scale that goes from 1 to 10.

On a recent day, Foss cranked the key, took a deep breath, and shifted the car so it lumbered forward down the dusty road in front of her home. She turned into a parking lot to avoid the main drag and circled almost three-quarters of the way around the block before pulling over to look at an appaloosa mare and her foal in a neighbor’s yard. This, too, was part of the routine. But it didn’t completely work, she confessed. Her anxiety was mounting.

“I’m at about a 3,” she said, though clearly believing that the number was about to leap higher.

This was not the day for a showdown. She decided to head home.

“For me and a lot of people, we’ve learned so much about ourselves, about feelings and dealing with them. But would I trade it for never having to experience this? Absolutely,” she said, her eyes filling with tears.

Foss regrets that her condition wasn’t treated properly when it flared up two decades ago. Had it been, she mused, she would not be faced with the painful battle today--a fight so rigorous that a simple drive around the block means coming home drenched in sweat.