What is route-based speed adaptation?

It’s a mouthful of a name: the Mercedes-AMG CLA 45 S 4MATIC+. It’s also an astonishingly capable car.

And it comes with a long list of features that are often quite arcane, including one that’s bundled up with the standard ‘Driving Assistance Package’. The feature in question is named ‘Route Based Speed Adaptation’.

This function takes adaptive cruise control to a new level. If you have the cruise set for 60km/h around town, the system will automatically reduce the car’s speed at roundabouts, and if you’re turning left or right at the roundabout, the system will power up the engine on the exit from the turn.

So, leave your feet right off the pedals and the car will automatically brake for you, even without a vehicle in front. Indicate to turn left and the car will brake to a speed that’s safe for negotiating the turn and then push the car back up to the speed you had previously selected.

It’s not perfect, of course. If an oncoming car is making a right turn in front of you at the roundabout, the system won’t make any allowance for that. The Mercedes will naturally come to a shrieking halt once the AEB detects the right-turning vehicle, but that’s hardly an elegant stop.

Another point about this system is that it adheres to the speed the driver has set, so if you’ve selected 60km/h for a 50km/h zone, the car will stick to 60km/h; it doesn’t automatically adjust for the lower speed limit. Benz is already working on that matter for the next developmental stage.

Notwithstanding quirks like that, the system is very impressive. It's Level 1 (‘feet off’) technology, but it is another incremental step along the path to fully autonomous (Level 5) motoring. There’s a school of thought that the CLA 45 might technically be a level-two vehicle, offering lane keep assist as it does.

The route-based speed adaptation system employs map data and also live traffic info, going one step beyond a conventional satellite navigation set-up to slow the car down for traffic jams on freeways, as well as reducing speed for bends and intersections.

And Benz has slipped it into cars like the CLA 45, the GLE and the all-electric EQC in a sensible way of introducing this type of technology to potentially reluctant consumers, who may be suspicious of a car that’s taking over the driving.

“You don't have to have it turned on, it's a function that you can enable if you want to. It's in the Assistance menu,” explained Ryan Lewis, Media Relations & Product Communications Manager for Mercedes-Benz Australia.

“It will slow down for a bend or... an intersection. It knows that that's coming up – and it has different thresholds, depending on the drive mode that you're in as well, so if you're in 'Comfort' it's quite conservative. It will start slowing down quite early.

“If you're on a winding country road, for example, and it's a 100km/h limit, it will slow down more in Comfort mode than it would in Sport+, for example. So Sport+ would be more likely to hold a quicker speed through the corners, because it assumes you're more engaged at that point, with driving. It's quite clever.”

Lewis is in no doubt that route-based speed adaptation is aimed at making the consumers buying the cars feel more relaxed that future semi-autonomous systems can deliver the goods and work in cahoots with other similar systems for a much safer, more user-friendly outcome on the road.

“A big part of the motivation to put it in the car is... kind of a psychological preparation for people, so that they kind of get an understanding of what sort of awareness [the car] has of its surroundings. It does serve that purpose; you get this idea of: 'Wow. OK, the car recognises exactly what's about to happen ahead and it's making allowances for that.'

“It's on the road to the future.”

And as much as the Mercedes-AMG CLA 45 S is a great drive, can anyone help but be amazed at how effective it is taking the driving out of your hands?

Away from your feet as well...