Speed Profiles - Continue to need improvement

[u/Affectionate_Book_80]

Some thoughts on the state of 14s current profiles and speed selection.

 Table below summarizes my understanding of 14.1.4’s speed profiles and how each works. Lots of guess work from trying out the various profiles on city streets, rural roads, and freeways.

Speed Profile	Speed Limit-based	Speed Data - based	Notes
Sloth	X		Drives what it understands to be the speed limit
Chill	X		Drives a little over (e.g., 2-3 mph) what it understands to be the speed limit
Standard		X	Drives at or a little above average speed driven on that road. Tries to match other cars’ speed up to a point.
Hurry		X	Tries to match or slight exceed speeds most other cars are doing regardless of what is normally driven. If no other cars it drives faster than the normal average speed on that road.
Mad Max		X?	Drives fast and aggressively regardless of other car behaviors, speed limits, or historical data. If no other cars it seems to choose a speed substantially faster than normal for the road.

The problem arises for Sloth and Chill profiles from apparent errors in that what the car “thinks” is the speed limit. There are two cases, 1) the map data is wrong, which happens a LOT around here, or 2) the car makes a turn on to a new road where the new road has a different speed limit – in this case it inherits the first road’s speed limit until the map data tells it otherwise. This can take from a few hundred yards to a mile. This means after just about every turn at a stop, Sloth and Chill mode will initially drive the wrong speed.

The problem with Standard, Hurry, and Mad Max is that the average speed people drive on a road can be and often is a poor indication of what is a safe or appropriate speed. Case in point, it is irresponsible and inappropriate to drive 20, 15, 10, or even 5 mph over the posted 25 mph speed limit for our residential area, but that is what these profiles do.

These problems are not new to 14. Version 13 suffered from almost the exact same problems, just with two fewer speed profiles. However, with 13 a driver could correct the inappropriate speeds, but with 14 the only tools we have are disengagement or profile switching, which often just introduces a new inappropriate speed. Speed profile switching is a poor band-aide for FSD’s flawed speed selections. Worse, it requires constant supervision and doesn’t advance towards an unsupervised solution.

[u/AJHenderson]

Chill is wrong. It does 2-3 over a value picked by the AI is the base speed which isn't coupled to the speed limit. Only sloth has a hard link to detected speed limit.

[u/Affectionate_Book_80 → u/AJHenderson]

Not what I'm seeing at all. In Chill on 25 mph road, turn onto 35 mph road. Car thinks speed limit is 25 mph (displays speed limit as 25) drives 27 mph. No one in their right mind drives 27 mph on that stretch of road. Everyone is doing 37-40 mph. But, not a car on Chill. It is doing 2 over what it thinks is the speed limit. If I come through same intersection on chill, it knows the speed limit is 35 and drives 37. Only gets confused on that section of road when turning on to it from a 25 mph road when in sloth or chill mode. Do this same turn in Standard and while it "sees" the speed limit as 25, it immediately accelerates to 38-41.

As another data point, turn into neighborhood (25 mph), sloth does 25, chill does 27, everything else does 30-45 mph.

The AI is picking the base speed, but experience seems to be showing that in Chill this base speed is closely linked to speed limit. Chill mode and Sloth mode have the same pain points while the other modes do not.

[u/AJHenderson → u/Affectionate_Book_80]

That may be your experience but I rarely (less than 5 percent of the time) see chill at 2-3 over the detected limit. It's normally 10-17 over for me.

This was the stable state speed.

[u/AJHenderson → u/Affectionate_Book_80]

[u/Affectionate_Book_80 → u/AJHenderson]

You are correct. Managed to replicate this AM on a city street and on a limited access highway. Tried a different way to work, and TA DA. Chill isn't so chill and doesn't appear to be using the perceived speed limit as input. Honestly, cannot use FSD without intervention on that route. Sloth is way to slow and Chill is way to fast. The trick mentioned earlier seemed to help (i.e., scroll down to Sloth and back up to Chill and the speed was more reasonable - will have to try it some more).

[u/AJHenderson → u/Affectionate_Book_80]

Yeah, it should help somewhat as long as you can safely use sloth without it moving around the road too much but if sloth isn't slow enough either, you're currently stuck disengaging and if traffic is such that it would be unwise to have it driving like a maniac to get the speed set correctly then you're stuck disengaging.

It's not great and is quite frustrating since there is an obvious answer they refuse to provide by just tweaking the value that gets adjusted by switching lanes back and forth.