“The system looks at the profile of the road,” Volker says. “So if you have a curvy mountain road with a 100kp/h limit, but no one would drive it that way, the car would slow to whatever is comfortable for that kind of road. It will show you whatever the situation is in the dashboard.” Clever stuff.
If you’re approaching a roundabout, say, the system will slow the car from its set speed as you approach. If there’s something coming, you have to hit the brakes as you would normally – it won’t stop for you – but if there isn’t, you needn’t touch anything. Simply steer around the roundabout, and the S accelerates back up to speed once you’ve taken your exit. If you’ve got the GPS set it knows what exit you’re taking, and will plan accordingly. If not it does it on the indicator, whether you’re indicating left, right or not at all. This is all communicated to the driver via symbols that flash up in the instrument cluster – different ones for each reason the car might slow.
The way it brakes and accelerates varies too. More harshly in Sport mode, softer and less aggressively if you leave it in Comfort. Shove it in Sport + and it’s last of the late brakers. And because the GPS has been hooked up to the speed limit assist thing, the S knows what speed limits are coming and rather than retroactively braking once you pass the sign, will slow beforehand so you’re doing, say, 30mph as you enter a village.
Oh, but it can’t detect whether a traffic light is red or green, though Mercedes, “like everyone else”, is working on that.