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Follow Distance - Traffic-Aware Cruise Control

Follow Distance - Traffic-Aware Cruise Control

Reference: Page 81 of Model 3 Owner's manual

I'm hoping to better understand the follow distance feature of TACC. According to the manual, each number/setting "corresponds to a time-based distance that represents how long it takes for Model 3, from its current location, to reach the location of the rear bumper of the vehicle ahead of you". In normal driving highway driving situations (i.e 60mph +), time is essentially equivalent to distance since 1 second is roughly equal to 1 car length (dependent on speed). However, in a bumper-to-bumper congested traffic situation, even setting the number to "7" does not leave an adequate amount of space with the car in front to allow other cars to merge without my car coming to a complete stop.

T L | 2020年1月16日

(2/2 due to access denied)
It leaves about 1.5 car length of space because the follow distance is based on time, not distance. Traffic where I live is consistently some of the worst in the country and it would be more efficient to allow more space between my front bumper and the rear bumper of the car in front of me. Many times, drivers will not merge into that distance on their own and get frustrated until I take over, allow them to merge, then reengage TACC. Then, when traffic does speed up, my follow distance is set to "7" which is not ideal.

What are your experiences with follow distance?

FISHEV | 2020年1月16日

" However, in a bumper-to-bumper congested traffic situation, even setting the number to "7" does not leave an adequate amount of space with the car in front to allow other cars to merge without my car coming to a complete stop."

I use TACC all the time in rush hour and it works great. I think it is more dynamic than the setting implies. The slow speed shortens the distances and I think it is really looking at braking distance not "car lengths" so it stays close but safe at low speeds. At slow speed, 10-20 miles an hour, I'm typically leaving more space than other drivers (I use 4) and people will see the space coming and hit their blinker but I will usually have to tap the brakes to let then in unless they are aggressive and go for it. Tesla acts a bit rude then, it doesn't seem the coming over initially so it is speeding up to catch the other car until it sees the merging car, looks like I'm trying to cut them off at last minute if I leave it to TACC.

On highway it leaves an easy merge spot to the point the drivers in back will tailgate.

T L | 2020年1月16日

@FISHEV
You are right - It IS looking at braking distance not "car lengths". In your example in traffic, you would take back control to allow other cars to merge and then reengage (which can be annoying if done 15 times over the course of a trip). I'm wondering if it would make more sense to change follow distance parameters at slower speeds.

I agree that it works great at higher speeds!

NorthValley | 2020年1月16日

Got mine set to 2 and never had any issues. Very useful feature

FISHEV | 2020年1月16日

"I'm wondering if it would make more sense to change follow distance parameters at slower speeds."

I'd prefer it just use "safe distance" to control it even it means we have to intervene to be public minded drivers.

TACC already suffers from too much FSD influence. We still have the inappropriate braking, braking for map data and other issues with Tesla's adaptive cruise, TACC.

On some of the slow, high merge spots where there's a definitive zipper point, I'll leave the Tesla in TACC to stay close and discourage merging until I get to the zipper point and I'll take it off TACC.