Phantom slow spot on 65mph highway?!

[B52SES]

I have noticed that long term road work seems to impact the speed limit (EX: I-5 in North County SD), was this area under construction recently?

We travel between northern Virginia and Sarasota, FL about 3 times a year; 4-5 times car autopilot cruise control does the same; drives us crazy.

 

[tennisDr99]

there is an area, perhaps 20 -50 feet long where my car thinks the 65mph speed limit is 40mph. it slows down quite suddenly. The spot is on my way home from work so it happens every day.

Is there anything I can do to fix the mapping data that is inaccurate with Tesla? or is it not Tesla that provides the data? if so, how can I fix it with them?

This happens to me on I-4 north of Orlando - which is due to new construction! DANGEROUS

 

[Ribeye67]

Last weekend my wife and I were on Highway 4 driving westbound on autopilot near the border with Antioch and Brentwood, CA going 70 mph on a 65 mph highway. with no car in front of us the Model X slammed on the brakes as if it was coming to a stop on the highway. It scared the crap out of us. luckily a car wasn't behind us. If one was behind us it would probably have hit us before I had a chance to react and hit the accelerator. The phantom braking is so unpredictable unless you drive that way often. I have a predictable spot on Highway 24 westbound near Broadway not far after exiting the Caldecott Tunnel. In that case it slows from 65 mph to 55 mph. Not as scary but the first time it happened it was.

 

[sllvgl]

Hit one phantom slow down on 101 N in Burlingame CA at Peninsula Ave exit. Slows to 45mph if driving on the right lane, seems okay if on the left most lane. Should be fixable via software update.

 

[BenderTmoc]

For those in this thread who have had a phantom brake incident multiple times in the same location, I would be very curious what openstreetmap shows the speed limit to be in that exact spot.

I think I read somewhere that although AP3 cars can now recognize stoplights and signs, the car will only warn you if you're about to run one if OSM has a light or sign in that spot in its database. Maybe the cars are using OSM speed limit data as well. If OSM has the wrong speed limit for a 50 foot stretch of highway, perhaps that explains the phantom braking.

 

[mxnym]

For those in this thread who have had a phantom brake incident multiple times in the same location, I would be very curious what openstreetmap shows the speed limit to be in that exact spot.

I think I read somewhere that although AP3 cars can now recognize stoplights and signs, the car will only warn you if you're about to run one if OSM has a light or sign in that spot in its database. Maybe the cars are using OSM speed limit data as well. If OSM has the wrong speed limit for a 50 foot stretch of highway, perhaps that explains the phantom braking.

Based on lots of experiences like this and some messing around in OSM, I'm confident in saying that OSM speed limit records are NOT related to this issue. The cause is proprietary GPS data that Tesla uses, but good luck knowing when/if they're going to fix any given issue. I had a spot on a new highway where my X would drop below 45 in a 70 for nearly a minute if I didn't take over, and the service center reviewed it several times before saying it was GPS data, but it was 6 months to a year after that before the problem went away with a map update.