The  current design calls for a roundabout that is 150 feet in diameter. All four approaches to the roundabout  have two lanes entering and two lanes exiting, except for the northern approach from South State, which will include a third lane. The planned design features include non-motorized paths that connect with the existing sidewalk system and new on-road bike lanes. Underground electrical conduit will be installed for the possible future addition of advanced pedestrian-activated crossing signals (HAWK) or rectangular rapid flash beacons (RRFB). [.pdf of State/Ellsworth roundabout layout]

Of the total $2.520 million project cost, $2.170 million is for the intersection improvements per se, and the remaining $350,000 is for a city water main improvement. That will replace a 20-inch water main, which serves to pipe untreated water from the Steere Farms wells on the Ann Arbor municipal airport property to the city’s water treatment plant. The city of Ann Arbor is paying for the water main portion of the project as well as contributing $135,000 to the intersection improvement. The remaining cost is paid by the road commission ($135,000), Costco ($500,000) and a federal Congestion Mitigation and Air Quality (CMAQ) grant ($1.4 million). Costco is building a store near the intersection that’s expected to open this summer.

This brief was filed from the city council’s chambers on the second floor of city hall, located at 301 E. Huron. A more detailed report will follow: [link]