Lights, camera, action

Volvo says the S60 is the most dynamic car it has made. Photo / Supplied

Richard Livock pulled out of Volvo's main office in the new S60 sedan and headed for the motorway onramp at Greenlane. It was late in the day, traffic was at its peak and Livock was headed home across the Auckland Harbour Bridge.

It was a trip he'd made hundreds of times. But this one would be different: he was attempting to drive 12km in bumper-to-bumper traffic without using the car's brake or accelerator.

Volvo NZ's national service manager had switched on the S60's Active Cruise Control, an optional package of watchdog electronic gizmos that, when all things are equal, allows the driver to focus only on steering the car.

It's basically a radar unit, keeping the S60 at a safe distance from the vehicle ahead and watching what those at either side are up to. Bit like KiTT from the television series Knight Rider. In this case, Livock programmed the system to slow and stop the S60 within 10m from the car in front.

"To be honest, it gets a bit dodgy at traffic lights, coming up behind a line of cars," he said. "It's hard not to stop your foot from hovering over the brake pedal. There are some ballsy moments - but the system will do it."

Four electronic bars on the S60's instrument panel point to the programmed stopping distance. One bar is 10m, four bars is a maximum 40m.

"I could have set it to four bars, but drivers on the motorway will inevitably pull across in front of you to close up the gap," he said. "Setting it at one bar stops people pushing in."

If the Volvo is stationary for less than 3 seconds, electronics step on the gas to get it moving again. Any longer - at lights, for instance - and the system goes into standby. Cue the driver's right foot to get it moving again. Same to stop the car, if the S60 is at the head of a line of traffic with nothing in front for the radar to lock on to. (That said, tests have been done with software that responds to traffic lights).

Optional ACC is central to Volvo's most ambitious aim: preventing any crash deaths in a Volvo by 2020. There are other safety systems too.

One is "pedestrian detection". It worked driving through a village in Portugal at the launch of the S60 earlier this year. Workmen were repairing a stretch of footpath and, as I slowed near a corner, perhaps doing 25km/h, one of them strayed into the car's path.

In an instant, perhaps a quarter of a second, an interior alarm sounded and a warning light from the driver's display flashed.

The system's radar, camera and advanced software was telling me and the car's computer brain that we were about to hit a human being. Its "full autobrake" component had already pre-charged the car's anchors. It did so because Volvo had programmed the software to recognise a pedestrian's pattern of movement and to calculate whether they were likely to step in front of the car. The system can detect pedestrians 80cm tall and upwards.

Had the workman kept coming, the system would have told the car to jump on the brakes. Quicker than I could have managed. I was still wondering what all the noise and flashing lights were about when the system returned to normal. The workman stayed put. Danger averted.

"We've driven more than half a million test kilometres in real traffic to 'train' the system to recognise pedestrians' patterns of movement and their appearance in different countries and cultures."says Thomas Broberg, senior safety adviser at Volvo Cars.

The system expands on Volvo's City Safe technology, a low-speed collision warning programme first seen in New Zealand in the carmaker's XC60 SUV.

That system prepares for heavy braking and, if need be, automatically jumps on the brakes with up to 50 per cent of full braking power if the driver has not responded to the alert. The new system applies 100 per cent braking power.

Pedestrian detection consists of a radar unit in the car's grille, a high-resolution camera in front of the interior rear-view mirror, and a central control unit.

The radar's task is to detect any object in front of the car and to determine the distance to it. The camera determines what type of object it is. The control unit decides whether to brake or not to brake, or to disengage drive to all wheels to aid braking. All this in half a second, says Volvo.

The carmaker claims the system can avoid a collision with a pedestrian at speeds up to 35km/h. At higher speeds, it focuses on reducing the car's speed as much as possible before impact.

The S60 landed in New Zealand this week. Volvo says it is the "most dynamic" car it has made. Three sedans are available, each using a turbocharged engine mated to six-speed automatic gearbox with manual mode.

The entry level example costs $63,990 and uses a four-cylinder 177kW/320Nm 2-litre petrol engine to drive the front wheels.

The remaining two models are all-wheel-drive. The solitary diesel costs $71,990 and carries a five-cylinder 151kW/420Nm 2.4-litre unit. The top-range T6 costs $79,990 and has a 3-litre in-line petrol unit under the bonnet, delivering 224kW/440Nm.

The mid-size four-door is the Swedish carmaker's best model yet.