Zero pedal driving - anyone else done this?

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Sparky17

Member
Joined
Apr 19, 2015
Messages
20
On the way home from a plug-in vehicle conference in Concord NH to Merrimack, I was coming down the Everett Turnpike and had cruise control set. I have active cruise control turned on. It detects a vehicle in front of the i3 and automatically slows down and speeds up to maintain a safe distance. It uses a camera on the front of the rear view mirror to do this.

Anyway, there was (is) construction in Manchester on the Everett, and traffic was going anywhere from 65 mph (which is what I had CC set to) to as slow as a 4 mph crawl. I was amazed to discover that without me touching the CC controls or either the brake or accelerator even once, the i3 was smart enough to keep about the exact following distance I would have kept all the way through. The only time I had to do anything at all was when a car was merging in front of me from the right. This created a new car that I was following, and closer. Rather than hit the brake, I just slightly steered the car to aim it at the new car, and it responded instantly as soon as it "saw" it.

That was last week. Last night I was following my wife home from Manchester - she in her Prius. I tried the experiment in town. I set the CC to 45, which we were doing on DW Highway North of town. I followed her all the way home without touching either pedal - about 8 miles total. We stopped at a stop sign, and turned at several corners, as well as slowing and speeding up to 35 (her base speed in town) for other cars turning and entering and so forth. Typical "city" driving. It worked perfectly. I didn't have to touch brake or accelerator till I was about to pull into our driveway. The i3 did pretty much exactly what I would do in any of those traffic situations.

Quite impressive. All I had to do was steer and monitor what the car was doing in case I needed to take control, which I never had to do.
 
I almost always drive with the ACC on and set to 5 mph over the speed limit. It is a very relaxing way to drive. However, one must remain vigilant because the ACC camera can be confused by shadows, etc., or blinded by the sun, both of which are likely to cause sudden unexpected decelerations due to the aggressive regen. I've learned to anticipate some of these potential problems and to keep my foot poised to accelerate or brake, if necessary. But overall, I love ACC.
 
What I forgot to describe in my original post is that in that construction/traffic jam in Manchester, the ability to let the car do it took pretty much all of the tension, frustration, and general aggravation out of what is usually a stressful driving situation. So it's not just impressive, it's very useful in that circumstance.
 
Sparky17 said:
What I forgot to describe in my original post is that in that construction/traffic jam in Manchester, the ability to let the car do it took pretty much all of the tension, frustration, and general aggravation out of what is usually a stressful driving situation. So it's not just impressive, it's very useful in that circumstance.

I agree with you, it is the one shining feature of the i3 that I really am enjoying so far. I do the same in slow or stop/go traffic and not worry about the driving skills of my fellow road travelers in terms of maintaining speed. You just have to be Zen in that people will keep squeezing in in front of you because everyone else thinks it ok to drive bumper to bumper!
 
coupedncal said:
I don't have this feature and i am just curious how does the camera detect stop signs and traffic lights?

I don't think it does, you have to follow a car ahead of you. It does that very well.
 
The ACC will not stop unless there's a vehicle in front of you that has stopped...otherwise, it will joyfully just keep cruising along. IOW, it does not interpret stop or signal lights at all, just vehicles in front (or merging or crossing) of you. If I'm in that situation, I usually just tap the off button, which pauses the ACC (like most BMW's), and have my foot on the go pedal to slow as I wish. If you just hit the brakes, the act of removing your foot from the go pedal means probably too rapid deceleration.
 
If you have Park Assist you also have everything needed to have the car self steer below 25mph while in ACC. I wonder if this can be coded into a NA car like it is in the Eu and Uk versions....... This is a feature that was promised in BMW's online literature but never made it to NA with no explanation given.
 
Yeah, the biggest problem with ACC that I've found is crusing along at 45-55 mph on a 2-lane and either having a red-light ahead or a car stopped at the red light. You have to intervene in either case. With the car stopped in front scenario, the ACC doesn't detect it far enough in advance to slow you down in a reasonable manner.
 
I find the i3 to be far less stressful to drive in general, but the ACC especially so in rush hour highway travel.

It's pretty clear where the future is going on these kind of driving aids and it's going to happen faster than a lot of people realize, but you'll still have to be an alert and attentive driver for quite some time yet.
 
I like the ACC on single lane roads; not so much on interstates. I've been setting the ACC to 75 MPH (the speed limit) on I-25 which means that I am slower than most traffic. So I will drive in the right lane and the i3 will slow down as I approach behind a slower car. But I often won't notice that the car has slowed down until I happen to look at the speedometer and notice I'm going slower than 75. I suspect I don't notice the slowdown due to the lack of engine noise.

In order to pass the slower car I usually have to use the accelerator. The gaps between cars are usually small enough that were I to try to change lanes without pressing the accelerator the ACC would determine that the car newly in front of me after the lane change is too close and rapidly decelerate, even if that car is going faster than I am.
 
I know few people do this, but the ideal following distance is 2-seconds of travel (60mph/88fps*2, 176'), so it will vary based on how fast you are going. The car is just trying to follow those safety guidelines. That gives you some time to notice a problem developing and then not have to make an emergency maneuver, which may affect that idiot who is behind you that is not following those safety guidelines. AT least how our liability laws are written, if someone hits you from behind, it's almost always their fault. There are a few exceptions, but they generally include you doing something really stupid or dangerous.

One of my pet peeves is the idiot that is literally riding on my bumper at any speed other than at a stoplight. I know he will not be able to stop if I had to make an emergency stop for some reason. It gets even worse in the winter when traction is compromised.
 
Yes, as has been pointed out several times here, ACC is not a substitute for an alert and competent driver. There are a lot of situations it's not "smart" enough to cover. But it sure is nice in a traffic jam, and for most highway driving as long as you still pay attention. Takes most of the stress out.

JAD: I think there must be a special place in Hell for tailgaters.
 
There are only two kinds of tailgaters:
1. Those that have been in an accident
2. Those that will be in an accident

:lol:
 
i try to use ACC as much as possible and the 35mph self steering on freeway is excellent.

Someone tailgatting - I was always taught to add extra space in fron so that you have room to brake for the idiot behind you. Fine judgement when some other idiot will dive into that gap in front of you.

I generally set the distance to the shortest when in heavy traffic to close up the gap.
 
barrychan said:
With the acc on and when it comes to a complete stop, then the traffic begins to flow i need to press the accelerator for it to move is that right?
I think the car will start moving on its own but with far too much delay. Pressing the accelerator or the cruise control Resume button will start the car moving sooner than it would on its own.
 
barrychan said:
With the acc on and when it comes to a complete stop, then the traffic begins to flow i need to press the accelerator for it to move is that right?
barrychan said:
With the acc on and when it comes to a complete stop, then the traffic begins to flow i need to press the accelerator for it to move is that right?
It depends somewhat on how long you've been stopped.
 
jadnashuanh said:
It depends somewhat on how long you've been stopped.

Correct. If the forward vehicle being tracked moves again within a few seconds, the i3 accelerates on its own. But if traffic stops for a longer interval, the driver has to press the accelerator pedal or the RES button to restore autonomous mode. I haven't timed it to figure out when the system switches modes but there's a visual indicator in the instrument display. The ACC symbol is green while the system is active and will resume on its own. It switches to orange if traffic stops too long and moving again requires driver action. It's probably a safety system to ensure the driver remains alert.
 
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