AASHTO TURNING TEMPLATES - GENESIS ?

[WAMBUS]

I interested in how the templates were developed. Specifically, for a given turning template, how fast is teh subject vehicle assumed to be traveling? At issue is the fact that our DOT says a perticular intersection does work on paper, but trucks use it all the time. The templates do not appear to show a vehicle 'cranking' over the wheel at a stop to make a tight turn. Can anyone help me with this?

Thanks!

 

[ACtrafficengr]

Wambus, do you mean DOT says it does not work?

There was an article in a Trasnportation Research Record about 10 years back on developing a turning template for a schoolbus. You could use TRIS Online to find the article, and take a trip to your neares university with a CE department to read it.

I don't recall anything about speeds. The part I remember is they had pipettes full of paint on the corners of the vehicle, and surveyed the paint streaks left on the pavement.

On all the turning templates I've seen, the circular arc transcribed by the outside front bumper is tangent to the approach. I would think that if the driver stopped, then turned the wheel to the stops and procieded, that there would be a break in the line.

"...students of traffic are beginning to realize the false economy of mechanically controlled traffic, and hand work by trained officers will again prevail." - Wm. Phelps Eno, ca. 1928

"I'm searching for the questions, so my answers will make sense." - Stephen Brust

 

[SunilCal]

Have you looked at AutoTurn software, they may have information. From what I remember, template trucks are going about 15 mph. The templates are conservative, you can find assumed information (like how hard they cut the wheel, I can't remember the proper term for that). You can move the templates around and combine paths, there are some instructions in the manual. The binder here is from ITE.