Landform is working on an updated master plan for The Cor (a large mixed use/neo-traditional development in Ramsey, MN that has struggled due to the economic downturn). They brought me in to update some traffic forecasts which Mark Lenters (Ourston Roundabout Engineering) can use to redesign a key intersection in the development.
How close can an intersection controlled with a roundabout be to another intersection? Based on operational experience around the country, much closer than if the intersection was controlled with a traffic signal – often a couple hundred feet is all the spacing that's needed. This is pretty well established and why Mark was brought in for this project, but how close can a roundabout controlled intersection be to a traffic signal controlled intersection that has dual left turn lanes at it?
I raised this question to Mark early in the project and he's been kind enough to share the real world example (below) at Utah Valley University in Orem, Utah. There's only 200 feet between the roundabout and University Parkway. I haven't found any references to how well this area operates, but it's a creative example of putting a roundabout close to a large intersection.