During the following days I hired a series of cars from the studio rental company, choosing every available variant of the automobile, from a heavy American convertible to a high-performance sports saloon and an Italian micro-car. What began as an ironic gesture intended to provoke Catherine and Renata – both women wanted me never to drive again – soon took on a different role. My first brief journey to the accident site had raised again the spectre of the dead man and, more important, the notion of my own death. In each of these cars I drove along the accident route, visualizing the possibility of a different death and victim, a different profile of wounds.

Despite the efforts made to clean these cars, the residues of the previous drivers clung to their interiors – the heelmarks on the rubber mats below the driving pedals; a dry cigarette stub, stained with an unfashionable lipstick shade, trapped by a piece of chewing gum in the roof of the ashtray; a complex of strange scratches, like the choreography of a frantic struggle, that covered a vinyl seat, as if two cripples had committed rape on each other. As I eased my feet on to the control pedals I was aware of all these drivers, of the volumes their bodies had occupied, their assignations, escapes, boredoms that preempted any response of my own. Aware of these overlays, I had to force myself to drive carefully, as I offered the possibilities of my own body to the projecting steering columns and windshield vizors.

At first I aimlessly followed the perimeter roads to the south of the airport, feeling out the unfamiliar controls among the water reservoirs of Stanwell. From here I moved around the eastern flank of the airport to the motorway interchanges at Harlington, where the rush-hour traffic leaving London swept me back in a huge tidal race of metal along the crowded lanes of Western Avenue. Invariably, at the hour of my accident, I found myself at the foot of the flyover, either wrenched past the collision site as the traffic jerked away towards the next traffic lights, or stalled in a massive jam ten insane feet from the precise impact point.

When I collected the American convertible, the rental company salesman remarked, 'We had a job cleaning it up, Mr Ballard. One of your TV companies was using it – camera clamps on the roof, all over the doors and bonnet.'

The notion that the car was still being used as part of an imaginary event occurred to me as I drove away from the garage in Shepperton. Like the other cars I had hired, this one was covered with scratches and heel-marks, cigarette burns and scuffings, translated through the glamorous dimension of Detroit design. On the pink vinyl seat was a deep tear large enough to take a flagstaff or, conceivably, a penis. Presumably these marks had been made within the context of imaginary dramas devised by the various companies using the car, by actors playing the roles of detectives and petty criminals, secret agents and absconding heiresses. The worn steering wheel carried in its cleats the grease of hundreds of hands held there in the positions dictated by the film director and the cameraman.

As I moved in the evening traffic along Western Avenue, I thought of being killed within this huge accumulation of fictions, finding my body marked with the imprint of a hundred television crime serials, the signatures of forgotten dramas which, years after being shelved in a network shake-up, would leave their last credit-lines in my skin.

Confused by these beckoning needs, I found myself in the wrong traffic lane at the junction with the motorway interchange. The heavy car, with its powerful engine and over-sensitive brakes, reminded me that I was being too ambitious in thinking that I could fit my own wounds and experience into its mastodonic contours. Deciding to hire a car of the same model as my own, I turned into the airport access road.

A massive traffic jam blocked the tunnel entrance, and I pulled across the oncoming lanes and drove into the airport plaza, a wide area of transit hotels and all-night supermarkets. As I drove out of the filling station nearest, the tunnel slip-road I recognized the trio of airport whores strolling up and down a small traffic island.

Seeing my car, and presumably thinking that I was an American or German tourist, the eldest of the three women came across to me. They paced about on this traffic island in the evening, gazing at the speeding cars as if trying to pick up travellers waiting to cross the Styx. The three of them – a talkative brunette from Liverpool who had been everywhere and done everything under the sun; a timid and unintelligent blonde, whom Catherine clearly fancied from the way she often pointed her out to me; and an older, tired-faced woman with heavy breasts who had once worked as a filling-station attendant at a Western Avenue garage – seemed to form a basic sexual unit, able in one way or another to satisfy all comers.

I stopped by the traffic island. The older woman came forward as I nodded to her. She leaned against the offside door, her strong right arm pressing against the chromium window pillar. As she stepped into the car she signalled with her hands to her two companions, whose eyes were flicking like windshield wipers across the light-impacted glass of the passing cars.

I followed the traffic stream through the airport tunnel. The woman's hard body beside me in the rented American car, unknown star of so many second-rate television serials, made me suddenly aware of my aching knees and thighs. Despite its servo-brakes and power steering, the American car was exhausting to drive.

'Where are we going?' she asked as I left the tunnel and headed towards the terminal buildings.

'The multi-storey car-parks – the top decks are empty in the evening.'

A loose hierarchy of prostitutes occupied the airport and its suburbs – within the hotels, in discotheques where music was never played, conveniently sited near the bedrooms for the thousands of transit passengers who never left the airport; a second echelon working the terminal building concourses and restaurant mezzanines; and beyond these an army of freelances renting rooms on a daily basis in the apartment complexes along the motorway.

We reached the multi-storey car-park behind the airfreight building. I drove around the canted concrete floors of this oblique and ambiguous building and parked in an empty bay among the cars on the sloping roof. After tucking the banknotes away in her silver handbag, the woman lowered her preoccupied face across my lap, expertly releasing my zip with one hand. She began to work systematically at my penis with both mouth and hand, spreading her arms comfortably across my knees. I flinched from the pressure of her hard elbows.

'What's the matter with your legs – have you been in an accident?'

She made it sound like a sexual offence.

As she brought my penis to life I looked down at her strong back, at the junction between the contours of her shoulders demarked by the straps of her brassiere and the elaborately decorated instrument panel of this American car, between her thick buttock in my left hand and the pastel-shaded binnacles of the clock and speedometer. Encouraged by these hooded dials, my left ring-finger moved towards her anus.

Horns sounded from the concourse below. A flashbulb flared over my shoulder, illuminating the startled face of this tired prostitute with her mouth around my penis, faded hair spilling through the chromium spokes of the steering wheel. Pushing her aside, I peered over the balcony. An airline coach had rammed the rear of a taxi parked outside the European Terminal. Two taxi-drivers and a man still carrying his plastic briefcase were lifting the injured driver from his cab. A huge traffic jam of buses and taxis blocked the concourse. Flashing its headlamps, a police car climbed on to the sidewalk and moved through the passengers and porters, knocking over a suitcase with its fender.

Distracted by a flicker of movement in the chromium windshield pillar, I looked to my right. Twenty feet away across the empty parking bays a man with a camera sat on the bonnet of a car parked against the concrete balcony. I recognized the tall man with the scarred forehead who had watched me near the accident site below the flyover, the doctor in the white coat at the hospital. He released the opaque bulb from the flashlight and kicked it away under the cars. As he pulled the film from the back of his polaroid camera he eyed me without any particular interest, as if well-used to seeing prostitutes and their customers on the roof of this multi-storey car-park.

'You can finish. That's all right.' The woman was now searching my groin again for an errant penis. I beckoned to her to sit up. When she had straightened her hair in the rear-view mirror she left the car without glancing at me and walked to the elevator shaft.

The tall man with the camera sauntered across the roof. I looked through the rear window of his car. The passenger seat was loaded with photographic equipment – cameras, a tripod, a carton packed with flashbulbs. A cine-camera was fastened to a dashboard clamp.

He walked back to his car, camera held like a weapon by its pistol grip. As he reached the balcony his face was lit by the headlamps of the police car. I realized that I had seen his pock-marked face many times before, projected from a dozen forgotten television programmes and news-magazine profiles – this was Vaughan, Dr Robert Vaughan, a one-time computer specialist. As one of the first of the new-style TV scientists, Vaughan had combined a high degree of personal glamour – heavy black hair over a scarred face, an American combat jacket -with an aggressive lecture-theatre manner and complete conviction in his subject matter, the application of computerized techniques to the control of all international traffic systems. In the first programmes of his series three years earlier Vaughan had projected a potent image, almost that of the scientist as hoodlum, driving about from laboratory to television centre on a high-powered motorcycle. Literate, ambitious and adept at self-publicity, he was saved from being no more than a pushy careerist with a Ph.D. by a strain of naive idealism, his strange vision of the automobile and its real role in our lives.

He stood by the balcony, looking down at the collision below. The headlamps illuminated the hard ridges of scar tissue above his eyebrows and mouth, the broken and re-set nose bridge. I remembered why Vaughan's career had come to an abrupt end – halfway through his television series he had been seriously injured in a motorcycle crash. All too clearly his face and personality still carried the memory of that impact, some terrifying collision on a motorway in the North when his legs had been broken by the rear wheels of a truck. His features looked as if they had been displaced laterally, reassembled after the crash from a collection of faded publicity photographs. The scars on his mouth and forehead, the self-cut hair and two missing upper canine gave him a neglected and hostile appearance. The bony knuckles of his wrists projected like manacles from the frayed cuffs of his leather jacket.