Welcome to Tesla Motors Club
Discuss Tesla's Model S, Model 3, Model X, Model Y, Cybertruck, Roadster and More.
Register

HW2 Tesla. Are you supposed to use Traffic Aware Cruise Control on local roads?

This site may earn commission on affiliate links.
I tried it the other day, worked pretty well when the road is straight and the car in front of you behaves.
Had a near accident when the road was a bit curved, and the car in front switched off to the next lane.
It completely missed the next car in front and started accelerating.
Luckily, my nerve response time was pretty good I guess.

what's your experience?
 
Generally-speaking TACC isn't designed for use on any roads that have intersecting roads. It totally ignores cross traffic, as well as stationary cars. For example if you approach stopped cars at a red light ahead, the car won't identify those stopped cars, leading to late hard braking (AEB) or a crash.

I use it from time-to-time on those roads anyway, but I trust it only as much as a conventional cruise control. Anything it does that is smarter than that is icing -- I'm ready for it to do the "dumb thing" at all times.

On the highway I have much higher expectations :)
 
  • Like
Reactions: croman
I use it all the time but I disengage TACC manually using the stalk anytime I don't have a lead car or approach a light with a "stale" green and no lead car. You've got to maintain situational awareness at all times and treat it like vanilla cruise that can adjust it speed as required. In my opinion, there is little to no point in using it on roads with stop signs or where stop lights come more frequently than 1 mile intervals. I also only use it on roads with >40mph speeds because traffic usually just goes straight and there is minimal lane shifting.
 
TACC will go any speed with a maximum (currently) of 75mph. The 5mph over is probably just your offset speed limitation. You can adjust that to 10mph but you can always go to 75mph by moving the stalk up (little movements give you 1mph big ones do 5mph increments). Read the owner's manual and your release notes if you are unfamiliar with the operation of any AP feature before you use it. TACC works wonderfully for me. I've been using it a lot and other than sharp winding roads, it hasn't had any issues (I've had 2 false FCWs where it suddenly slowed my car and threw the red car of death and chimed at me but if you touch the accelerator or brake it will disengage and allow you to decide what to do (I chose to proceed on since after scanning it looked all good)). Each time it was a big hill and the radar was bouncing off the road and fooling the car into thinking we would somehow slam into the road.

The key is that the system is continually uploading its data to the Mothership and the updates we get are the crystallization of that learning data. The system will improve based on your experiences (whether AP is engaged or not). However, engaging AP does help accelerate the GPS tile based knowledge (the hill situation if you continually drive on the same road will improve if you press the accelerator when FCW comes on and it will learn humans don't brake when approaching hills and that it is a false FCW).
 
Generally-speaking TACC isn't designed for use on any roads that have intersecting roads. It totally ignores cross traffic, as well as stationary cars. For example if you approach stopped cars at a red light ahead, the car won't identify those stopped cars, leading to late hard braking (AEB) or a crash.
I've seen this said many times but in my experience the car has no problem seeing a stopped car and decelerating appropriately. I wouldn't try it at highway speeds but at up to 40 it seems controlled and stable. Seems to start slowing down even before the dash displays the stopped car ahead.
 
I've seen this said many times but in my experience the car has no problem seeing a stopped car and decelerating appropriately. I wouldn't try it at highway speeds but at up to 40 it seems controlled and stable. Seems to start slowing down even before the dash displays the stopped car ahead.

Over 14,500 miles I've had maybe 2 instances where HW1 did not successfully detect a stopped car. So I would say there's a very small chance of it happening, but it's not zero. I would definitely be alert but generally expect the car to do the right thing.


Usually the recognition failures happened with dark colored cars with blacked out taillights that were out (e.g. it seems like brake lights are a key component in the EyeQ3 stopped car recognition algorithm)
 
in HW2, it only detects the same lane cars. When cars turn or leave the lane, it does not track them as well as HW1. Right now HW2 is definitely way way less dependable than HW1 but that gap will narrow and be eliminated shortly. Also HW2 isn't as smooth as HW1 so even when it does detect the lead car (which will turn white in the IC to indicate a radar lock), it doesn't initiate a deceleration until much closer that target car than AP1 which results in a harsher braking experience. A/S is much much better for some reason at maintaining a safe distance and tracking the car in front.
 
  • Like
Reactions: pilotSteve
The important, operative word with these features is "assist." The car may assist the driver to drive, but the driver still needs to remain vigilant and assist the car. Until we have cars that all are talking to each other on the road, we won't have much of a true "autopilot."

This is some pretty cool stuff, though, isn't it?