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Hi there, unfortunately no....

It all depends on the design guidelines (required turning speed) and the space available... You may want to have a look on the table of the "minimum horizontal curve radius" in AASHTO...

No volume option can be found in the software...

Throughout my career, I've seen two groups of people, some prefer to do it like how it is shown in the video by specifying speed as well, and the other group they do it as what you mentioned with Centerlines... Thanks Shawn for sharing your experience in Alberta...!

@@ImadBalich hmm thanks, good to know. I am assuming both ways are workable. The reason for doing centerline curves is to count for different turn radius with different speed when turning through traffic islands.

Pat Calderon there are many Roundabout design guidlines and standards that talk about the entry and exit curves, some share the same concepts and some differ depending on the region. Yet, in general Entry curves have a great influence on the operation, safety and capacity of a roundabout, thus, the larger the Entry curve (up to 20m to 25m) the better is the capacity, but, the speed is also an important factor that should be looked at. The Exit curves have also an influence on the operation and safety of roundabouts, some guidelines mention that it's a good practice to keep Exit curve not smaller than the circulating curve, and not significantly greater; to ensure low speeds at the downstream pedestrian crossing (if available).

Thanks! I am designing a roundabout with five legs and I am finding a hard time deciding on which entry radius and exit radius I should use. I simulate with Vissim 10 and it shows no drastic improvement. I will try to enlarge the inscribed circle diameter to have a larger entry/exit curve as you said it will have better capacity. Our guidelines limits the entry radius to be less than the central island radius. Again, thanks!

Pat Calderon What governs the Entry and Exit Radii is the Inscribed Circle Diameter (ICD), as you said earlier you should choose an appropriate ICD for your roundabout which is mainly a function of two factors, the design vehicle (Passenger car (16m), Single-Unit (29m), WB-12 (30m), etc...) and the allocated area available... You're welcome... Wish you all the best...

Auto-Turn is a software that acts as an add-on to AutoCad. You may refer to the link below for their website: transoftsolutions.com/home

It's called AutoTurn by Transoft Solutions, You may refer to the link below for their website: transoftsolutions.com/home

Sorry Abdul Jamil for not including the voice, i will consider it in the upcoming videos. Yes, the 90 degrees is the angle of the line, to input it follow the steps below: To start drawing a line you need to Input the length of the line first (in the video it's 100m), then, press TAB on your keyboard to input the angle of the line (in the video it's 90), then, press Enter. I hope I answered your question...

thanks for that. do u mean TAB instead of TAP because i can't see a tap key. when i click on TAB key the angle is 90 but then the original length of 100 no longer is the length of that line. can you explain plz ?

You may watch the video below to help you with your concern... ruclips.net/video/6TfRjUy4vD0/видео.html

Thanks for that i will have a look at that now.

Hi Haydar, Auto-Turn is a software that acts as an add-on to AutoCad. You may refer to the link below for their website: transoftsolutions.com/home

you're Welcome africano... Regarding the roundabout design, well it's a very wide subject. In designing of roundabouts, we do have two main concerns, 1st is the geometry ( Horizontal and Vertical) of the roundabout and 2nd is the Drainage (Grading).

1stYes, 2nd am not sure what do u mean

africano chan you can have some ideas here: www.site3d.co.uk/help/roundabout-junction-vertical.htm

thanks

You're Welcome Ercan...