Speed Limited on Autopilot

[Struja]

Something happened to me today which has never happened in the 2+ years I’ve owned my car.

As I was driving to work I was using AP and the speed limit was 100km/hr. I was on a well marked, nicely paved and completely straight stretch of highway and the AP was set to 112km/hr. I drove like that for about 3km, when suddenly the car slowed and I got a message saying something like “auto steer limited to _____”. The limit on the highway did not change, the condition of the road did not change, the traffic was light, so any idea what happened?

I had to exit the highway shortly after so I did not get a chance to figure out if this was just a temporary glitch. Thoughts?

(I should probably add that I just updated to 2019.24.4)

 

[ronm2948]

I get that message frequently, and I think it is generally on roads that are not divided. It limits my speed to 5mph over the limit.

 

[ATX37]

Something happened to me today which has never happened in the 2+ years I’ve owned my car.

As I was driving to work I was using AP and the speed limit was 100km/hr. I was on a well marked, nicely paved and completely straight stretch of highway and the AP was set to 112km/hr. I drove like that for about 3km, when suddenly the car slowed and I got a message saying something like “auto steer limited to _____”. The limit on the highway did not change, the condition of the road did not change, the traffic was light, so any idea what happened?

I had to exit the highway shortly after so I did not get a chance to figure out if this was just a temporary glitch. Thoughts?

(I should probably add that I just updated to 2019.24.4)

There was a map update being rolled out at the same time as 2019.24.4. I wonder if this has to do with this.

 

[Struja]

I get that message frequently, and I think it is generally on roads that are not divided. It limits my speed to 5mph over the limit.

What does “not divided” mean? I was on highway 427 South which has two sets of lanes heading south (local - we call them collectors) and Express.

 

[Snowstorm]

What does “not divided” mean? I was on highway 427 South which has two sets of lanes heading south (local - we call them collectors) and Express.

I know exactly what you are taking about. I get this frequently on 401 W collectors by Mavis. Autosteer is limited to speed limit +10kmph on non freeways, and the map data isn’t always accurate. If there are construction that changed the road, the car can think you are on a parallel street or off ramp instead, so it goes from freeway with no limit on autosteer speed to unknown non freeway with implicit 70kmph speed limit, which caps autosteer at 80kmph.

 

[Struja]

I know exactly what you are taking about. I get this frequently on 401 W collectors by Mavis. Autosteer is limited to speed limit +10kmph on non freeways, and the map data isn’t always accurate. If there are construction that changed the road, the car can think you are on a parallel street or off ramp instead, so it goes from freeway with no limit on autosteer speed to unknown non freeway with implicit 70kmph speed limit, which caps autosteer at 80kmph.

Yes, I have had that happen on two lane highways in rural areas but in this instance, the car was still showing 100km per hour as the speed limit so, I did not think the issue was that it limited my speed because of changing limits (and there is no construction in that area).

 

[steve1313]

I have a few areas where I get that message. One is a narrow, two lane windy road with almost no shoulders, so that makes sense. However, the others are on a stretch of road that is part of a divided four lane highway with well marked lines, wide shoulders and no curves. The message/restriction lasts for about half a mile.

 

[Rogue Synapse]

I get this message pretty much every time I try to use autopilot anywhere other than the interstate. It seems to limit autopilot to no more than 5 mph above the speed limit in town.

Sidebar to our Canadian friends:
I wish I grew up thinking of distance and speed in terms of kilometers instead of miles. My parents generation had a chance to make the switch away from the arbitrary imperial system to the scientific and rational metric system and really screwed it up.

 

[Struja]

Sidebar to our Canadian friends:
I wish I grew up thinking of distance and speed in terms of kilometers instead of miles. My parents generation had a chance to make the switch away from the arbitrary imperial system to the scientific and rational metric system and really screwed it up.

Having lived in the USA for almost 14 years (of my 46) and having an American wife and two American born kids...we are all thoroughly messed up. Metric for most, but we still use lbs for the most part and I can’t seem to shake the occasional “oh, it’s about a mile down the road”!!! LOL

 

[BridgeMojo]

It's most easily explained by a patch of bad map data showing some section of highway as not being limited-access. You may find that it always repeats in the same spot until it's fixed in a map update.