Wolfsburg, Germany - The streaks of colour on concrete bollards, the corners of buildings on car wings and mudguards speak louder than words - parking is a big problem for many motorists, even long after they have passed the driving test.

Carmakers already offer customers a range of on-board sensors and cameras to aid reversing while some models feature dashboard monitors with graphic displays. These are all designed to ease the squeeze into awkward parking spaces, yet the unsightly dents and scrapes on car bodywork persist.

Help is however at hand. Semi-automatic parking aids which take control of the steering wheel and guide the driver into tight spaces are being offered as an option by a growing number of manufacturers. Indeed the hybrid Toyota Prius became the first car to offer an automatic parking aid several years ago.

The system fitted to the Prius measures the size of the parking space available before manoeuvring the vehicle into the selected spot. In theory, all the driver has to do is use the brake and throttle. In practice though, the car will crawl into the parking space and disengage the assistant just before the final resting point. This puts the driver back into control in order to finish off the job.

"Thanks to the advances made in electromechanical power steering, parking assistants can be offered in many more cars these days," said Stefan Borsig who works at the development department of Volkwagen in Wolfsburg. VW's Park Assist is an option on the Tiguan, Touran and passat CC models. Mercedes-Benz has recently introduced a similar system for the A and B class ranges, said spokesman Frank Bracke in Stuttgart.

All the current parking assistance devices have a major snag. They only work for what is known as parallel parking, namely the typical roadside gaps found in towns and cities. None of the robot parkers are good at identifying the sort of perpendicular gaps found in parking lots and in underground car parks.

Enter VW's "Park Assist Vision" self-parking system which can guide the prototype Passat with absolute precision into a pre-selected parking space using cameras and ultrasound sensors. Provided the gap is big enough, the driver can even get out and leave the car to do the rest.

By pressing the remote control, the driver activates a system which computes the manouevre needed to enter or drive out of a given parking space. The device sends commands to the car's steering and electronic brake and during the operation the engine is kept running at iding speed only. If the sensors detect an obstacle the car is immediately brought to a stop, said Borsig.

The innovative driver assistance device fitted to the Passat is still at the development stage and Borsig said no date has yet been set for the system to enter series production. Refining the gadget is likely to take a couple more years, according to VW's development chief Juergen Leohold.

Along with the sophisticated electronic parking assist systems, there are other devices on the market designed to take the trouble out of parking. The Renault Laguna GT saloon features four-wheel steering billed as "Active Drive". It is said to boost driveability and steering precision at all speeds. The turning circle of the car is smaller too which makes it easier to slot the Laguna into awkward city parking spaces. Four-wheel steering will be an option for the next generation of BMW's upmarket 7 series limousine due to be unveiled in the autumn.

The Around-View Monitor (AVM) on the new Infiniti FX and EX offroaders gives the drive a bird's eye view of the car in forward and backward motion. This impressive piece of cabin gadgetry is enabled by a set of four mini cameras mounted in the bumpers which project images onto a monitor, explained Infiniti spokewoman Nathalie Buettner. The result is a real-time, 360-degree view of the car at low speeds which helps drivers overcome blind spots and the other pitfalls of everyday parking situations.

This is just the kind of assistance which drivers need, says VW's Borsig. Parking today's often longer passenger vehicles such as vans is particularly tricky since they often negotiate the curves in car parks but encounter side obstacle farther in, he pointed out.

VW has adapted its car sensors to take this into account and a prototype displays the driver on a dashboard monitor a corridor within which the vehicle can negotiate the hazards of a typical multi-storey carpark and find a berth without suffering panel damage.

"If the dimensions are too tight the system sounds an alarm," said Borsig. The improvements will eventually find their way into future models.

VW development chief Leohold believes that even more sophisticated parking aids could soon become viable. These so-called "robot valets" would enable cars to self-park without any assistance from the driver. It may sound like something from the pages of science fiction but the driver and occupants would be able to go off and do the shopping, leaving the car to search for a vacant space on its own. (dpa)