keeping to the speed limit

[janner]

Drive Assist Plus displays the current speed limit on the screen. I can set Drive Assist Plus to go at any speed and it will do so unless the car in front goes slower.

I would like to be able to set the car so that I can drive at any speed up to the current speed limit displayed on the screen but no faster and to change that maximum whenever the speed limit changes. Is there a way to do this?

Alternatively to give me an audible warning if I exceeded the displayed speed limit - I know I can set an audible warning but I have to set the speed of the audible warning manually and change it when the speed limit changes.

 

[stumbledotcom]

I don't believe what you're looking for is possible with the current systems. At this point any BMW with Speed Limit Info (feature is not unique to the i3) simply displays a facsimile of the most recent sign detected by front camera. That info is not passed along for other systems such as Adaptive Cruise Control to use. While I've found the detection impressively accurate at picking out speed signs along cluttered road sides, it's not 100 percent. It cannot for example distinguish limits that only apply at certain times such as school or construction zones. Think of the technology as an information supplement; you the driver still must judge and react to driving conditions.

 

[i3an]

I've wondered about this too and my suspicion is that it is disabled for liability reasons, as the BMW sensor and mapping technology is not nearly there — yet. In some situations the GPS has a hard time determining exactly which road you are on, for example a freeway or the frontage road, or if you are under a flyover it cannot immediately determine if you are on a city street below or the freeway above; then include rain/snow/ice, temporary road works and such, and you would have an accident or a speeding ticket and a lawsuit waiting to happen. I could see it being implemented first for semi-autonomous driving on freeways, only when you have plugged in your destination (like Tesla), but not for general driving just yet.
Note that the Google autonomous bubble cars, as envisioned, are to be limited to 25 mph on select fully-mapped-out urban areas, with a driving style of Granny on Xanax, hardly suitable for the Ultimate Driving Machine™.

 

[jadnashuanh]

I look at it this way...there are often situations where it is not safe to go the set speed limit. If the car automatically adjusted itself to that, you could find yourself going too fast for the conditions. Driving is the operator's responsibility...all of the tools may make things safer, but we are not yet ready for autonomous operations, especially in our litigious society in the USA. The attitude that it is always someone else's fault is just too prevalent - people just don't seem to want to take responsibility for their actions and to defer it to a vehicle is (at least for now) probably asking too much.

FWIW, the nav system has a database on speed limit information, but it is augmented by the camera in areas where that information may not be available. IOW, often, the speed limit info is displayed based on the on-board stored information, so if that changes and you've not updated your map data, you could have an issue, but hopefully, the camera would pick up the change.

You'll know if you're in an area with database speed limit info when it shows up and you've not seen a sign. If it is vacant or dashes...it's searching for a sign since it doesn't know. This often happens on smaller roads.

 

[janner]

Just to clear up any confusion, I don't want the car to take me to the max speed I set - Drive Assist does that already and as has been said here, in some circumstances, that's too fast - the driver needs to be in control.

So taking it from the driver being in control how do I get the car to have a 'do not exceed' speed that I can drive up to but not go past? And how do I then get the car to set that 'do not exceed' speed automatically when it sees the speed limit sign?

My old ICE Mercedes had an easy set up for 'do not exceed' speed.

Ford's new S-Max does what I want to do with the i3. http://money.cnn.com/2015/03/25/technology/ford-speed-limit/index.html

 

[stumbledotcom]

You can set a speed limit manually in the EcoPro menu. It applies only when you're in EcoPro mode. Note: the EcoPro+ speed limit (55 mph in the US; not sure in other markets) cannot be changed.

The BMW system does not dynamically adjust either the speed limit set in EcoPro or the speed set with ACC.

 

[websterize]

...how do I get the car to have a 'do not exceed' speed that I can drive up to but not go past?

That sounds similar to the LIM function available in other BMWs. Push a button on the steering wheel, and it's set. Some drivers have reprogrammed the SET button to LIM via coding, but I haven't read about it being done in the i3. I'd find LIM most useful in 30-mph zones in cities/towns teeming with speed cameras — they're everywhere in Maryland.

See http://www.bimmerfest.com/forums/archive/index.php/t-669435.html for more details on the LIM function.