Activating a left turn traffic signal....?not

[powerdoc]

I have not yet purchased my i3 but I did an extended test drive and it seems that the car didn't trip left hand turn lane signals. In my area, left lane turn lights are actuated by a car travelling over a wire loop to alter a current therefore actuating the light. Is there so little ferrous metal in the i3 that it won't do this or did I just hit the loops at the wrong time? The "genius" line at BMW didn't know.

 

[MikeS]

It would help if you told us where you were - you can put it in your profile.

 

[powerdoc]

Done! I guess in the UK it would be activating a Right turn signal! :lol:

 

[SanSerif]

The perennial problem for cyclists - traffic sensors don't detect a bike and after a while you get fed up watching nothing happening and have to blast through on red.

I'd briefly wondered of a primarily carbon structured i3 would suffer a similar fate at the lights - but so far it hasn't. Which is a relief - I didn't fancy going up before the beak[1] and trying to explain it all.

[1] I have no worries when cycling - they'd have to catch me first!

 

[i3Alan]

In my area, left lane turn lights are actuated by a car travelling over a wire loop to alter a current therefore actuating the light. Is there so little ferrous metal in the i3 that it won't do this or did I just hit the loops at the wrong time?

The road loop sensors work better with aluminum than steel. The magnetic hysteresis of the metal is what interferes with the RF signal in the loop to indicate the presence of a vehicle. That hysteresis is much higher in aluminum.

My guess is that the loop failure you describe is a failed amplifier in the loop detection system at a particular intersection. When these amps are working and at their max settings, a small bicycle or metal roller skates can easily trip them. Small objects like an aluminum pocket comb waived quickly just over the loop can do it if the loops are not buried more than a few inches below the road surface.

If you want to maximize the detection of your car, and can easily see the outline of the loop, then make sure your wheel goes directly over one side of the loop, and moving at least a few MPH. Some installations use rectangular loops and some use round. The technique of putting your allow wheel over the coil works best with rectangular loops near the corners.

FYI, my smartass knowledge base on road loops is from discussions with an engineer for one of the loop system manufacturers when I was trying to make our community gates responsive to a resident's wheelchair (so he wouldn't have to use his clicker to unsafely exit the entrance gate).

 

[elptex]

FYI, my smartass knowledge base on road loops is from discussions with an engineer for one of the loop system manufacturers when I was trying to make our community gates responsive to a resident's wheelchair (so he wouldn't have to use his clicker to unsafely exit the entrance gate).

You are awesome! (Not being sarcastic/smartass--100% genuine)

 

[powerdoc]

OK, then, I'm corrected. I just need to aim the wheels more accurately.

 

[tiburonh]

I have not yet purchased my i3 but I did an extended test drive and it seems that the car didn't trip left hand turn lane signals. In my area, left lane turn lights are actuated by a car travelling over a wire loop to alter a current therefore actuating the light. Is there so little ferrous metal in the i3 that it won't do this or did I just hit the loops at the wrong time? The "genius" line at BMW didn't know.

I have no idea how things work out in praline country, but I drive my i3 in the San Francisco Bay area, and I have encountered absolutely zero problems here in getting turn signal or stop light signal loops to recognize the presence of my car with timing equal to their recognition of the presence of my former ICE vehicle (an Audi Q5).

Plus -- the i3 accelerates so quickly in urban driving that I find I can safely zip through yellow lights in many, many more instance than I could in my Q5

 

[Boxbrownie]

The perennial problem for cyclists - traffic sensors don't detect a bike and after a while you get fed up watching nothing happening and have to blast through on red.


[1] I have no worries when cycling - they'd have to catch me first!

I think they just have....... :lol: