It takes a woman to work out how to park perfectly

20. April 2003, 17:10

By Mark Henderson, Science Correspondent ONE of the oldest axioms of male driving folklore, that women do not know how to park properly, has been exposed at last as a myth: the formula for the perfect parallel-parking manoeuvre has been calculated by a female mathematician. The scientific secret of manoeuvring your car into a tight space has been revealed by Rebecca Hoyle, of Surrey University, who has worked out a series of equations that will, apparently, get a Volvo estate into a Mini-sized gap.

The formula, which Dr Hoyle calculated after performing a mathematical analysis known as a shape in motion study, helps a driver to perform the consummate S-shaped manoeuvre, leaving the wheels flush with the kerb, but not so close that it is impossible to get out. It will work for any vehicle and any roadside gap, telling the driver whether or not it is worth even trying to fit into a particularly tight space.

Written out in full, the formula reads: p=r-w/2,g)-w+2r+b,f )-w+2r-fg max((r+w/2)²+f²,(r+w/2)²+b²)£min((2r)²,(r+w/2+k)²).

It takes into account the width of the car at the widest point (w), the midpoint between the axles (c), the distance from c to the front (f) and back (b) of the car, the minimum radius of the turning circle (r), the distance from the parallel car at the outset (p), the optimal distance from the kerb at the finish (k) and the distance from the car front at the finish (fg).

Though the sums look fiendishly complex, and you may think you need a maths A level to understand them, their message can be boiled down into a few simple tips that could save scores of bumps and scratches.

“First, you want to find a space that’s at least one and a half times as long as your car,” said Adrian Webb of esure, the car insurance company that sponsored the research.

“You want to start turning as soon as your back bumper is adjacent to the parking space. Then you lock the steering wheel towards the kerb, and go back until you get to an angle of exactly 45 degrees with the kerb.

“Then you turn the wheel to a full lock the other way. As the front of your vehicle approaches the kerb, straighten the wheel. If you turn too late, you will hit the kerb. If you turn too early, you will park too far away from the kerb.”

Dr Hoyle, who normally specialises in the mathematics of patterns, such as ripple effects formed by sand dunes, said: “The initial requirements for a perfect S-shaped parallel parking manoeuvre are the right starting position, the size of the gap available, and the correct manipulation and timing of the steering within the available turning circle.

“We recommend that it should be supplemented with some pure practical common sense, such as using reflections in cars to judge your position.”

Mr Webb said parallel parking was an important skill because most drivers prefer to park on the street rather than in a car park. Misjudged parking moves and other low-speed manoeuvres also account for an estimated £151 million of damage every year, he said.

His colleague, Colin Batabyal, said that esure believed parallel parking should become a compulsory element of the driving test. At present a learner has a 50 per cent chance of being tested on the manoeuvre. “We have to learn to park better as a nation,” he said.

Many men will take some convincing that the opposite sex can master the art of parking. An insurance company survey last year found that women were almost twice as likely as men to have a collision in a car park, 23 per cent more likely to hit a stationary car and 15 per cent more likely to reverse into another vehicle.

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