I always wanted to ask this and finally remembered - are speed limits always correct?

Discussion in 'Questions From New Drivers' started by NewNashGuy, Apr 29, 2012.

  1. NewNashGuy

    NewNashGuy Road Train Member

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    My truck can only do 65 and with a heavy load I can be pushed up to 75 mph. With clear weather conditions and when the road is rated at 70mph, is it possible to still tip over by going the speed limit on the road? I forget the mile marker, but on I40 east near Dickson, TN there are no warning signs and suddenly the interstate has what I feel is a sharp turn on a downhill. My truck accelerates to 70 mph and suddenly the road curves plus it is angled towards the grass so the truck leans even more.

    Every time I hit this turn I hit my brakes and freak out but I wonder if the speed limit allows it then I should just continue without brakes? I do not want to take the risk and tip over but I do not have enough experience to know how far the truck can lean without tipping over. Plus it seems trucks only tip over on ramps and never on the interstate due to turns correct? I know my info may not be correct so please do not insult me, a correct answer would be great thanks :)
     
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  3. otherhalftw

    otherhalftw R.I.P.

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    You can take any turn a thousand times slowly....one time too fast......


    You have certainly heard the ending to this story!
     
  4. NewNashGuy

    NewNashGuy Road Train Member

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    Yeah that is why always slow down but I seen other trucks take fast turns and they are fine on the interstate. I never heard or seen a truck tip over on a turn on the interstate by going the speed limit. When I hit my brakes on this turn other truckers fly past me so I want to make sure that I am not unnecessarily braking. I once tried to see if I could take the turn but I felt like I was leaning too much so I hit the brakes not to risk it.
     
  5. otherhalftw

    otherhalftw R.I.P.

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    Don't hit your brakes in the turn....the centrifugal force could be enough to send you past the tipping point.

    Slow as you approach the turn, then power through the turn....negates the centrifugal force. Ask any NASCAR driver!

    That turn wouldn't slow your travel time enough to matter....pay attention and find a land mark to remind you the turn is coming...stay slow/stay safe!
     
  6. NewNashGuy

    NewNashGuy Road Train Member

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    Yeah I understand that from my years of playing just about every race car game you can think of :p It is true that some video games handle the controls like real life. I know this since I can drive my car in the ice and slide around without ever losing control and it is not luck either :p Not to go off subject though, I kinda want to know how far the truck can lean before it is too much as I see so many drivers never brake on turns unless there is a steep grade sign or slower limit posted.
     
  7. 58Skylane

    58Skylane Medium Load Member

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    Yeah...... I've had that same issue with curves in the road that seem too sharp for the posted speed limit. Especially for my rig (racing transporter loaded heavy on the top level) which is kind of top heavy to begin with.

    When there are cautionary speed limit signs for curves, and looping off ramps, I usually slow to about 5mph under the posted speed limit.
     
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  8. BSD

    BSD Light Load Member

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    Alot of it also depends on what kind of trailer you are pulling, and where your center of gravity is.
     
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  9. otherhalftw

    otherhalftw R.I.P.

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    Every load is different...it all depends on how it is loaded.

    Top heavy...front/top heavy...low center of gravity, high CG....there are too many different scenarios to put an actual number on the speed or rate of lean. Also, no two trucks are going to react the same way....this is where experience and learning the specific "quirks" of your machine pay off.
     
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  10. LaBubba

    LaBubba Light Load Member

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    My thoughts on posted speeds is they are for cars not Tractor-Trailers.I always have my speed below the posted speed when I come to a curve.Also don't let it run wild going down a hill.If you are governed at 65 and are running 70-75 you are not in control of your rig.The only thing you can do is slow down,no way you are going to power out of a curve.
     
  11. Shoestring

    Shoestring Light Load Member

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    An unstable high centered load could easily shift, causing the truck to roll. Your the driver, if you feel it's unsafe to take the curve at speed, reduce your speed to what you feel is safe. Speed limits that are posted, are maximum allowed speeds, no one says you have to go that fast.(just keep it in the right lane if your going slower)
     
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