It's vaguely unsettling at first. Relax your hands on the wheel of Honda's ADAS (Advanced Driver Assistance System) equipped Accord at motorway speeds and you'll feel the car taking over. The steering nudges the car into the centre of its lane all by itself while the accelerator modulates itself, keeping a respectable distance between you and the car in font. It may not drive itself, but it's enormously impressive.

I remember being similarly dumbfounded the first time I drove what is now known as an 'adaptive cruise control system' in the Mercedes S-Class but that was back in 1998 and the technology has progressed a very long way since then. Honda's ACC system uses information from a millimetre wave radar fitted in the front grille and combines with the car's ECU to calculate the vehicle's driving parameters. Available when the car is travelling between 20 and 112mph, Honda's ADAS seems a whole lot cleverer than the a system I recently tried in a Lexus, which was often flummoxed by higher closing speeds and obstacles on the apex of sweeping bends.

ACC will apply the brakes quite firmly if it deduces the vehicle in front has done likewise, but there's only so much the system can manage. Sweep, for example, from a fast moving outside lane to a slow moving middle lane and the car will sound a buzzer and illuminate a warning light indicating that the system has waved the white flag and needs driver intervention. It will do likewise if a car swerves into your lane with little warning, so once again it's worth reiterating that this cruise control is an aid to rather than a replacement of proper awareness and driver anticipation. The driver can set how far apart he or she wishes to be from the vehicle ahead and the ACC system will smoothly accelerate back up to the programmed speed when any obstacles are cleared.

"Control freaks may not like it, but everybody else will agree that this ADAS technology is hugely impressive"

It's at its best when combined with the Lane Keeping Assist System (LKAS). Citroën have developed a system that alerts the driver when he or she drifts over the white lines on a major road, but Honda have gone a stage further and brought a system to market that makes it very difficult to do so in the first instance. LKAS uses a digital camera mounted at the top of the windscreen to study the road ahead. It then calculates the optimum steering torque - combination of human and assisted inputs - required to keep the vehicle in the centre of the lane. Take your hands off the wheel and you can see it doing its magic, but within ten seconds, the car detects the driver has stopped making any inputs and stops the electrical steering assistance.

Drive normally and it's an uncanny feeling, the car gently guiding you at all times. The better you are with your steering, the less LKAS will need to intervene, but combine LKAS and ACC (creating the ADAS package) and it can feel a little spooky, as if your Accord is being drawn along the road by a tractor beam generated by the vehicle in front. The driver always retains ultimate control, and LKAS is rather picky about the occasions when it will operate. In brief, you'll need to be travelling between 45 and 112mph and both right and left lane boundary markings must be visible on roads with no sharp bends. There needs to be constant driver input to the steering, no indicators activated and without so much steering input from the driver that the system thinks the car is trying to change lanes. I didn't get to try the system in adverse weather or at night, so I can't comment on how well the camera coped with these conditions but in daylight it worked extremely well indeed.

The ADAS system is an option on the range-topping Legend but it's been pioneered in the UK on the 2.4-litre EX Accord, for a total price of £26,377. If you're a long distance commuter or frequently cover big mileages on business, the ADAS system may well be a cost you can justify. The trouble is, most of these high mileage drivers will probably opt for an Accord diesel which isn't offered with the ADAS set up as yet.

If the marketing may well be a little wonky, there's precious little to complain about the technology itself. Once you've spent a few minutes with a manual to get to grips with the ins and outs of ADAS, it's relatively simple to use when on the move. All of the relevant buttons are grouped around the right hand side of the multifunction steering wheel, reducing the need to go groping around the centre console, and a clear LED display indicates how the system is performing, whether the cruise control has locked onto a target car and whether the camera can see the lane markings.

The rest of the Accord package is also very impressive, Honda having cemented its position as the most upmarket of the mainstream Japanese manufacturers in this market segment. Certainly neither the Toyota Avensis nor the Mazda6 feel anything like as refined at speed or as supple around town. Viewed from straight ahead, the Accord's nose is remarkably similar to that of the Mazda6, with a similar shaped grille and lights but the Mercedes-style indicators in the door mirrors, the jewel effect headlamps and extensive use of chrome give the Accord ADAS a boutique look.

As a technological showpiece, the Honda Accord ADAS is mightily impressive. A little more work needs to be done to refine it into a system that will get new car buyers willing to spend serious money for it, but the hardware and software is there and represents a sunk cost for Honda that can now be distributed across the product range. Expect to see many other manufacturers playing me-too very soon.