#MTBoSBlaugust Day 25: I totally math geeked out last night

So my neighborhood has a Google Group where everyone is able to post if they are having a garage sale, dates and times of bird walks and nature hikes, about the issues with mailboxes (don't get me started on that subject) and the crazy traffic that has come up at an intersection near where 3 schools are located.  This gave me some inspiration for either a WCYDWT or 3 Act problem for the kids.  I still need to hash out all the details once I learn all the space requirements.

Here's the background:
Last year there was just 2 schools near this intersection and now there are 3 all starting at the same time.  

The stars are where the schools are located

There's lots of congestion and people have also noticed people blowing through the stop sign near the intersection.  Then I saw this in the email thread:

And I started wondering, why isn't there enough room?  How much room is required for a roundabout or traffic circle?  Could that be applied to properties of circles and area in geometry or would that be better attacked in Algebra 2 and try to maximize the restrictions?

I found this when I started researching the construction requirements for a roundabout:

http://safety.fhwa.dot.gov/intersection/innovative/roundabouts/fhwasa10006/

I'm still researching a lot about it and how much more space is required compared to traditional intersections but when I get a problem or project or something worked out I'll update this post with it for anyone else that is interested in using it.

Gotta love the random inspiration I get!