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Maximum Speed - T-shaped intersection

  1. Feb 5, 2010 #1
    A couple of months ago I was pulled over by a police officer for running a stop sign. The officer claimed I "plowed right through" the stop sign. I honestly had no idea what he was talking about but wasn't about to argue with a cop. I realized after going back to check the intersection after being pulled over that he was referring to a stop sign that is at a "T-shaped" intersection where the stop is right before you turn from the one lane stem of the T to the upper right extremity of the T which is also a narrow road and the angle between the two roads was probably more like 80-85 degrees making it not a "true" T. I do not consciously remember the stop sign at all, but I believe that I stopped (I have never gotten a traffic ticket prior to this). Also, beyond the "top" of the T was a guardrail overlooking a small ditch. On top of that the stem of the "T", the road I was turning from was only about 0.3 miles in length after having come from another road. I was driving a mid-sized sedan. Basically I am wondering what's the maximum speed you could go from a 0.3 mile road that is about twice the width of a mid-sized sedan at a T-shaped intersection to make a right turn onto another road which is about the same width and where the angle between the two roads would be about 83 degrees without skidding or crashing through the guard rail that is on the far side of the intersection.

    I presume that it's not very fast especially given the short amount of time to build up speed and in all likelihood for your average driver such as myself who knows no special driving tricks, you would have to stop or do a heavy yield to even make the turn.

    The ticket situation is all over, I'm just personally curious now.
  2. jcsd
  3. Feb 7, 2010 #2
    Frictional force F=uN
    u=frictional coefficient tangent of the angle at which the material on the substance starts to slide . N= normal force (mass)*(g)
    F=mv^2/r centripetal force , m=mass of car , v= speed , r=radius of curve
    you can calculate the force at which the rubber tires would start to slide on pavement you could look up this coefficient or do and experiment , then you can calculate the speed of the turn. . I hope this helps that’s about all I could think of.
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