# Autopilot in the Rain, Dark



## Arth (Aug 23, 2018)

Had our Mod 3 for 3 weeks already and last night we got caught in the rain, at night. And we are talking Florida rainy season rain, quite moderate for what sometimes you experience in SW Florida but it was our first serious 'weather' situation since purchase.
It didn't take long for me to become an Autopilot fan and I am using it for 99% of my highway driving now. However, the rain was heavy, it was dark and there were 4 of us, all family, in the car so it didn't take long before I took over and drove the car manually to destination - drove by 3 accidents for the next 30 miles.
So, can anyone comment? Based on your own experience, how safe is Autopilot in the rain, on slippery roads? Is Autopilot aware and does it factor in road conditions? If not, should it auto-disengage, maybe when it detects a need to heavily use the windshield whippers?


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## MelindaV (Apr 2, 2016)

it will not react to weather (IE slow down), so the driver should adjust the speed +/- the speed limit to what you typically would for those conditions. With that said, the car does use the radar and sonar sensors in addition to the vision cameras, that a driver does not have, so in a way, AP should be able to handle rain better than a human.


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## littlD (Apr 17, 2016)

Recently, I was traveling between Saint Louis and Nashville TN. I encountered a very heavy rain storm after sunset, and Middie struggled like I would have trying to find the lane markers.

Remembering that Autopilot is an "Driver Assist" instead of "Driver Replace", I took over.

I see no evidence that Autopilot V8.1 takes road or weather conditions into account, although I have experienced some curves where the car slows down on its own to better handle it.

I'm hoping we'll see more features with V9 and beyond to further the safety we gain by using it.


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## Arth (Aug 23, 2018)

MelindaV said:


> it will not react to weather (IE slow down), so the driver should adjust the speed +/- the speed limit to what you typically would for those conditions. With that said, the car does use the radar and sonar sensors in addition to the vision cameras, that a driver does not have, so in a way, AP should be able to handle rain better than a human.


Yeah, I did lower the speed and increased the follow distance to 2, then 3 car lengths but, still, it didn't feel safe enough so I took over.


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## MelindaV (Apr 2, 2016)

Arth said:


> Yeah, I did lower the speed and increased the follow distance to 2, then 3 car lengths but, still, it didn't feel safe enough so I took over.


fyi - the following distance numbers are not specific to a car length, but just a scale. it varies based on speed. (and in my limited time driving a 3 on EAP, on a clear dry day had it much higher than 2-3!, so would set it to the max in foul weather myself)


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## garsh (Apr 4, 2016)

MelindaV said:


> fyi - the following distance numbers are not specific to a car length, but just a scale. it varies based on speed. (and in my limited time driving a 3 on EAP, on a clear dry day had it much higher than 2-3!, so would set it to the max in foul weather myself)


Someone said it was based on time, with each number being equal to half a second.


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## Michael Russo (Oct 15, 2016)

MelindaV said:


> fyi - the following distance numbers are not specific to a car length, but just a scale. it varies based on speed. (and in my limited time driving a 3 on EAP, on a clear dry day had it much higher than 2-3!, so would set it to the max in foul weather myself)


Typically don't go lower than 4-5 for my AP settings. And have not experienced any issue with rain. Key is the quality of the line paint tho'.


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## SoFlaModel3 (Apr 15, 2017)

Arth said:


> Yeah, I did lower the speed and increased the follow distance to 2, then 3 car lengths but, still, it didn't feel safe enough so I took over.


I'm east of you in Broward County, so I know the rain. My experience with autopilot over 7 months has been fantastic on low visibility.

I would suggest the following settings:

Normal conditions highway speeds, cruise follow of 3 is a nice balance

Normal conditions but highway starts to slow, cruise follow of 2 helps prevent you from getting cut off making for an uncomfortable ride but still safe.

Normal conditions in bumper to bumper, cruise follow of 1. Keeps the tightest gap but safe at bumper to bumper speeds.

In rain at highway speeds go the other direction from 3!


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## ChronoMaster1324 (Jul 9, 2018)

Drove through some light rain on a sunny day in Houston yesterday. The road surface became very reflective and the car had difficulty finding lane lines in those conditions unfortunately. Had to take over pretty quickly as the car started to lightly weave while searching for the lane.


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