General Road and Highway Discussion

[danbrotherston]

Does anybody know if there provincial (MiniTrans) requirements for roundabout layout in Ontario? Googling only gets me results like how to drive in a roundabout, or signage from the Ontario Traffic Manuals.

This goes to that image I post a bit a go of a Dutch-style roundabout done up with Ontario traffic markings. It had sharper right hand turns to enter land leave, just like Dutch roundabouts where as Ontario roundabouts all have slip-lane like entrances and exits so cars don't have to slow down very much (unless the roundabout is so busy that they have to stop).

I'm trying to determine if Ontario roundabout are designed that way for reasons of regulatory compliance, of it it's just traffic engineers just stuck in their groove and not adapting, like so much else about North American traffic engineering.

I suspect that the standards you are asking about can be found in the TAC manual that is used by—I’m guessing all Canadian road building organizations despite it not being AFAIK a regulatory requirement. It’s more an engineering liability requirement—use this book to not get sued. 

https://www.tac-atc.ca/en/publications-a...dian-roads

Transportation Association of Canada - Geometric Design Guide for Canadian Roads.

Unfortunately it is an expensive book and I don’t have a copy so I don’t know if it contains roundabout specific guidance or if it is just being cobbled together from other parts of the standard.