Been wanting to ask this for some time so here goes. When you run up on someone and the cruise applies the brakes, do the brake lights light up for folks behind you? I can't see them to know for sure.
Adaptive cruise control
- Thread starter Mophead
- Start date
Hmmm... I have no idea on that one... I've never come up on someone fast, just usually a slow decel.. I don't see anything in the manual.
Google AI says they do when actually braking but not when just using engine decel. Would be interesting to set up an experiment to know for sure because, you know, just because the interweb says it...
From my own experience in our CRV, there are times I sure hope it does as it brakes pretty hard coming up on stopped traffic vs just maintaining distance at speed going down the highway. It will bring you to a complete stop and go again, if you're trusting enough to let it!
From my own experience in our CRV, there are times I sure hope it does as it brakes pretty hard coming up on stopped traffic vs just maintaining distance at speed going down the highway. It will bring you to a complete stop and go again, if you're trusting enough to let it!
the Ferret
Daily rider since May 1965
not a fan of adaptive cruise ...my wife loves it on her car. Pay attention and I don't think you need it.
- Joined
- Sep 3, 2006
- Messages
- 430
- Age
- 70
- Location
- Richland Center, Wisconsin
- Bike
- 20 R1250RT
- 2026 Miles
- 018742
I can say for fact that the adaptive cruise on the 2023 and 2024 BMW R1250RT of Kevin Q @MR Q does in fact activate the brake light if his bike needs to slow faster than engine braking. I have followed him many miles and have asked if he activated the brakes or did the adaptive. Almost always his answer was that he did not apply the brakes.
Makes sense.
As far as I know they do light up just as if you were applying brakes.
- Joined
- Jun 23, 2012
- Messages
- 179
- Location
- Fond Du Lac, Wisconsin
- Bike
- 2024 BMW R1250RT
- 2026 Miles
- 015385
- Joined
- Sep 3, 2006
- Messages
- 430
- Age
- 70
- Location
- Richland Center, Wisconsin
- Bike
- 20 R1250RT
- 2026 Miles
- 018742
When following you on the slabs and your bike slows as it catches up to traffic, the brake lights do not go on. If you or your bike slow quickly then yes they do light up. We need to verify hill assist brake light on or off.
My Bronco Sport does iluminate the brake light during hill assist braking.
ST Gui
240Robert
As it's called adaptive cruise control I wouldn't expect it to light up brake lights until it actually uses the brakes to slow down. Then I'd absolutely expect it to light up brake lights.
Most cars don't end up downshifting to use engine deceleration. My car is over 25yrs old so just has Mk1 ModØ cruise control. Relying on it mean speeding up when terrain slows the car down. When going down declines it uses braking. In those instances the cruise control isn't deactivated as it is when I use the brake pedal.
I don't think it ever uses engine braking. I'd bet regardless of what cruise system is employed if and when brakes are activated the brake lights would be too. If adaptive cruise control "feels" it needs to slow the car down if the driver doesn't certainly it'd be was to let anyone behind you do know.
But then if everybody paid proper attention we wouldn't need adaptive cruise control or CHMSLs or even brake lights to begin with.
But we're humans. Some aren't perfect. Others want you to think they are.
Most cars don't end up downshifting to use engine deceleration. My car is over 25yrs old so just has Mk1 ModØ cruise control. Relying on it mean speeding up when terrain slows the car down. When going down declines it uses braking. In those instances the cruise control isn't deactivated as it is when I use the brake pedal.
I don't think it ever uses engine braking. I'd bet regardless of what cruise system is employed if and when brakes are activated the brake lights would be too. If adaptive cruise control "feels" it needs to slow the car down if the driver doesn't certainly it'd be was to let anyone behind you do know.
But then if everybody paid proper attention we wouldn't need adaptive cruise control or CHMSLs or even brake lights to begin with.
But we're humans. Some aren't perfect. Others want you to think they are.
I'm not sure if all the bikes follow this but on my now sold 2022 Civic with ACC yes the brake lights came on when the car applied brake.
On my 3 month old 2026 Honda CRV yes the brake lights come on when the ACC applies brakes. There is even a little CRV car on the center of the dashboard that displays "status" all the time. If I manually apply the brakes the little tiny cute rear lights light up on the dashboard car. If the ACC uses the brakes the tiny dash car show brakes. This car also uses a camera and radar to see and display lanes on the dash, vehicles it detects on the dash and the last speed limit sign the camera see's (including construction zone temp signs) is shown on the dash along with a pointer mark arrow around the speedometer showing the current speed limit.
I'm a big fan of older low tech type cars but I had to drive 94 miles (3.5 hours) yesterday in high traffic conditions. From Innerarity Point to far north Milton FL. hauling my wifey, her Aunts and pets. I let the CRV do the gas and brakes and lane hold most of the drive and I am a BIG fan of ACC cruise on this car. It keeps the car 5 lengths back at speed and slows to a complete stop in traffic ahead slow downs.
PSS>
If you aren't a fan of ACC you switch it back to regular CC with a 3 second button press.
On my 3 month old 2026 Honda CRV yes the brake lights come on when the ACC applies brakes. There is even a little CRV car on the center of the dashboard that displays "status" all the time. If I manually apply the brakes the little tiny cute rear lights light up on the dashboard car. If the ACC uses the brakes the tiny dash car show brakes. This car also uses a camera and radar to see and display lanes on the dash, vehicles it detects on the dash and the last speed limit sign the camera see's (including construction zone temp signs) is shown on the dash along with a pointer mark arrow around the speedometer showing the current speed limit.
I'm a big fan of older low tech type cars but I had to drive 94 miles (3.5 hours) yesterday in high traffic conditions. From Innerarity Point to far north Milton FL. hauling my wifey, her Aunts and pets. I let the CRV do the gas and brakes and lane hold most of the drive and I am a BIG fan of ACC cruise on this car. It keeps the car 5 lengths back at speed and slows to a complete stop in traffic ahead slow downs.
PSS>
If you aren't a fan of ACC you switch it back to regular CC with a 3 second button press.
st11ray
2023 Yamaha Super Tenere
I hate acc. If I'm catching you, I'm going to pass you. If traffic is too heavy to pass, I'm not going to be using any type of cruise control.
I'm a service advisor at an Acura dealership. I don't trust any of the "safety" electronics on cars these days.
I'm a service advisor at an Acura dealership. I don't trust any of the "safety" electronics on cars these days.
drrod
Site Supporter
To me, it is not a giant leap from letting ACC take control over how a driver deals with traffic to this.....
ST Gui
240Robert
This ^. If you don't like it don't use it. It's that simple.
My car is too old for AAC so it's just CC. I seldom use it. On a rare occasion I do passing someone is as easy as accelerating. When the pass in complete get off gas and the CC resumes. Touch the brake and it disengage.
Maybe all distractions (aka amenities) should be removed from cars...
A/T
A/C
power windows
power steering
power brakes
ABS
radio
...facilitating that razor sharp focus motorcyclists innately possess.
I totally agree. Riding a motorcycle and driving a car are two different things. The ACC takes one more step towards making the riding experience like a car. You're removed from the situation when you're depending on ACC. You're like the passenger in the car, not the driver; just along for the ride.
I have CC on my bike. It is the most unnerving feeling to have it on in a turn. I know mentally that the corner is safe at the speed I'm doing, but when it kicks in the gas without warning...how much do I trust it? Or do I train myself to trust it and let go of the control of my bike?
Agreed. As you get more and more disengaged with what you're doing...why not fall asleep?
Agreed again. But we don't "need" adaptive cruise control. That makes an assumption I can't control my bike at the speed I'm doing...but doesn't make me responsible for my actions. I am responsible for what I'm doing and if I'm not? --then I need to quit riding or driving.
Was ACC initially proposed by the marketing department or the engineering department? I'll be marketing was looking for one more thing to convince people to buy this car or motorcycle because it has this.
Chris
ST Gui
240Robert
Nor do we "need" cruise control. It's merely a convenience.
Like cruise control. Power windows. Radio. Stereo radio. A/C. A/T
Strip all that crap out for a bare bones dependable vehicle and you have— one that won't sell. Oh sure someone will buy it. Not enough someones to make it profitable even for a niche demographic.
Build a vehicle that someone wants or build a vehicle and make someone want it— it's all about the Benjamins as the cool kids used to say. Whether the bright idea originates in Engineering or Marketing— it gets marketed.
Give enough engineering monkeys and marketing monkeys a factory and you may get a vehicle you truly love.
(Apologies to any engineers and marketing types. And especially monkeys.)
ST Gui
240Robert
I'm curious about the software behind this. The fast a vehicle moves the greater the stopping distance. Do you see this with ACC? The AAC begins to slow the car at different following distances depending on any given speed at the moment? I've noticed that some drivers/riders seem to follow as close as their reflexes will allow. Overall I see it as following too close though in practice it might not be. Assuming the reflexes are as good as the follower thinks they are.
I've always thought of ACC as sort of a Star Trek tractor beam. The car ahead slows you do too. It speeds up you do too. Except with an actual tractor beam you'd save on gas and brakes. Can't say the same for the GIF.
Or dilithium crystals.
I like the ACC on my bike. I don't really use it except on long rides and find that it is great on long highway rides when you have traffic slowing and speeding up. I never find myself complacent about it. One anomaly I found out about it was on my recent trip up to Canada to see my relatives a few weeks ago. I took the route home down through Eastern Oregon back to Reno and way out in the middle of nowhere the cruise control stopped functioning and I got an error message that it had a fault. I started to think about it and realized that a bit before the fault occurred I had ridden through a thick swarm of some kind of flying insects. I stopped and looked at the radar sensor and saw that it was covered in squashed bugs. I cleaned it off and the cruise control began working again. The ACC can easily be disabled by going into the settings menu and the cruise control can operate without the radar function. The ACC following distance is easily controlled with a switch.
I actually should have said I was following 1.5 to 1.8 seconds behind the vehicle in front of me. I was using selection 2 most of the day per Honda, see below. I find in today's heavy traffic If I follow as far back as I want to then that 3 second space is filled by the cars hurrying to pass everyone from the adjacent lanes.
Yes it does back you off at higher speeds and is selectable with the interval setting. At "4 bars" and 80 mph it follows at 3 seconds or 352 feet. Same setting at 25 mph is 3 second or 110 feet. You leave 110 feet at 25 mph ahead of you and it will soon be filled by another car. The average car length I found for 2026 is 14.7 feet.
You do understand I bought the Civic and the CRV for my wife's safety mainly? I'm still super manly tough and smoke cigars when Jack gives them to me. I was in a terrible fist fight just last week but luckily I beat her good.
Honda ACC Interval Chart
| Interval Setting | Approximate Time Gap | Instrument Panel Icon | Description |
|---|---|---|---|
| Short | ~1.0 - 1.2 seconds | 1 bar | Best for moderate traffic; leaves just enough room for safe braking. |
| Middle | ~1.5 - 1.8 seconds | 2 bars | The default setting upon vehicle startup; recommended for normal highway driving. |
| Long | ~2.0 - 2.3 seconds | 3 bars | Provides a larger buffer; great for higher speeds or light rain. |
| Extra Long | ~2.5 - 3.0+ seconds | 4 bars | Maximum distance; best for heavy rain, snowy conditions, or open rural driving. |