sudden deceleration on highway

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New member
Nov 27, 2022
Yesterday I was driving about 60 MPH in my 2019 Leaf, and passed under what appeared to be overhead lights near the Loudon Speedway in NH. These lights probably direct people to parking on race days. They were off and covered with some kind of small tent like frame so I can't be sure what they were. As I passed under, my car rapidly decelerated for about a second, an orange warning light appeared for a very short time on my dashboard, and I think a beeping sound occurred. It was pretty creepy. I am going to call the state and maybe the electrical utility to see what that overhead structure was, but any idea what was going on? (The speedway did have a LOT of Christmas lights set up around the racetrack.)

Somewhat related to this (maybe), sometimes when I pass a police car or a state sign such as they use for traffic control (big boxy sign with sighted letters), a beep will go off. But no rapid deceleration has happened before.
Welcome to the forum!

It sounds to me like the vehicle dynamic control (VDC) system kicked in because it may have detected a slippery patch on the road and reduced motor output. That yellow/orange light was probably the slip indicator light, which is turned on by VDC for a few seconds.
Thanks for responding. The thing is that it was well above freezing, and dry. Would that system kick in due to an electric surge or whatever?
Most ABS systems use magnetic Hall effect sensors that monitor the rotational speed of each wheel to determine when a wheel is spinning. It's possible some sort of electromagnetic interference was picked up by those sensors and this confused the ABS computer, causing it reduce or remove power to the wheel(s) thought to be spinning.

I've never heard of that happening though and I don't know why it would affect an EV more than other cars.
Bethann said:
The thing is that it was well above freezing, and dry.

Besides weather related things, slippery conditions can exist on the road due to small spills or droppings, like water, oil-based liquids, mud, small rocks/grains, roadkill, etc. It only takes a small patch of stuff to make your tire slip.
My 2022 Leaf just did this, while I was going 80 in the fast lane of the freeway. I completely lost the ability accelerate. I had to cross 5 lanes of traffic to the shoulder. I came to a complete stop, then was able to accelerate again. I’ll be bringing this to the dealer asap, but WTH!?!
Experiencing sudden deceleration on the highway can be unnerving and potentially dangerous. Whether due to unexpected traffic, road conditions, or mechanical issues, it underscores the importance of maintaining a vigilant driving mindset. Stay alert, keep a safe following distance, and be prepared to react swiftly. Regular vehicle maintenance and adherence to speed limits contribute to overall road safety, reducing the likelihood of abrupt deceleration incidents.
Is it just me or have there been a bunch of posts lately from new users that sound like someone is training ChatGPT on this forum?
I had Bing AI Chat search for posts from this user, Maria465. It found that the user recently joined a few groups, but had 1 post here:

That post sounds like an AI repeat post to me.