minimum road width based on turning radius
minimum road width based on turning radius
(OP)
I always thought 20' lane width is good enough but I'll be using smaller lane width this time.
This drawing is confusing as far as minimum road width required for 18-wheeler turning 90 degrees.
If I follow path of right - rear wheel, it looks like I need more than 20' road width?
This doesn't make sense.

This drawing is confusing as far as minimum road width required for 18-wheeler turning 90 degrees.
If I follow path of right - rear wheel, it looks like I need more than 20' road width?
This doesn't make sense.






RE: minimum road width based on turning radius
https://www.concordnc.gov/Portals/0/Documents/Fire...
http://arrow.dit.ie/cgi/viewcontent.cgi?article=10...
TTFN
I can do absolutely anything. I'm an expert!
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers
RE: minimum road width based on turning radius
for 18-wheeler to turn 90 degrees, I need 45' turning radius and more than 20' road width?
RE: minimum road width based on turning radius
TTFN
I can do absolutely anything. I'm an expert!
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers
RE: minimum road width based on turning radius
It really depends on the context. On a high speed rural road, a larger radius will allow the truck to complete the turn quickly and reduce the rear-end collision risk. In a city center, a tighter radius is often desirable.
RE: minimum road width based on turning radius
the swept path width, doesn't mean the width of the road required? the path of right rear wheel is not something I should be concerned about.
to confirm 20' wide road is more than enough for wb50 truck to make 90 degree turn. as you said only around 12' road width is required
RE: minimum road width based on turning radius
Do you have the complete Policy on Geometric Design of Highways and Streets (Green Book) that your turning template came from? If so, turn to the section on Design for Specific Conditions (Right Angle Turns) in Chapter 9.
Or is this a 90o bend in a roadway? In that case, turn to the section on offtracking and curve widening in Chapter 2. That describes how much added width you'll need, based on the vehicle type and centerline curve radius.
RE: minimum road width based on turning radius
this is what I mean. is 20' road good here?
yes I have green book and will look at chapter 2 and 9
RE: minimum road width based on turning radius
You'll need some curve widening. You'll need more room on the inside for the back wheel off-tracking, and wheels right at the edge of pavement will cause edge cracking. The minimum I'd use would be the "minimum edge-of-traveled way design" from Chapter 9. It's Exhibit 9-24, page 600 in the 2004 edition.
If you use a larger radius, you can use a narrower roadway. If you use 75' centerline radius, a 25' pavement width should be enough for most drivers in a WB-50.
RE: minimum road width based on turning radius
This is a low volume traffic inside private industrial site.
I just saw this in client specs. So you said, I don't need 75' centerline turning radius if I use curve widening.
RE: minimum road width based on turning radius
TTFN
I can do absolutely anything. I'm an expert!
FAQ731-376: Eng-Tips.com Forum Policies forum1529: Translation Assistance for Engineers
RE: minimum road width based on turning radius
RE: minimum road width based on turning radius
RE: minimum road width based on turning radius
RE: minimum road width based on turning radius
There is also a shareware / free edition of turning movement software, see http://www.glamsen.se/CadTools.htm. The author, Lars has a version for AutoCAD and Microstation. Pretty similar to the old v2.0 of AutoTurn. Forward movements only.
RE: minimum road width based on turning radius
thread163-332373: TURN.LSP Question
Dik
RE: minimum road width based on turning radius
RE: minimum road width based on turning radius
The cad file was developed by myself about 25 years ago from hand drawn drawings and the information came from a publication "How Big is a Truck and How Large does it Turn" or something similar. I've used the cad drawings for several projects.
Dik
RE: minimum road width based on turning radius
I'm sorry for that. Tom's site http://www.hawsedc.com/gnu/turn.php does reference Turn.Lsp as OpenSource and as developed with a co-author.
eea
RE: minimum road width based on turning radius
Others can use the Lisp link, thanks...
Dik