LAMORINDA WEEKLY | Deer Hill Roundabout Defeats Traffic Signal 3-2


A divided Lafayette City Council rejected calls for a conventional signaled intersection and approved the construction of a roundabout at the proposed entrance to the Homes at Deer Hill development in the eastern end of the city. Northern California-based O'Brien Homes will develop the 45 single-family home project that includes a 10-acre park, a sports field, a 2.9-acre dog park and a parking lot; the roundabout will lie adjacent to the entrance to the dog park. The council reviewed documents in November that recommended building a roundabout at the Deer Hill intersection but doubted whether it was a smarter solution than erecting a traffic signal. City engineer Tony Coe presented the council further information Jan. 9 confirming that not only will a roundabout be safer and less expensive, it will more easily comply with the requirements of the Americans with Disabilities Act. While a conventional intersection with traffic signals could be built at the Deer Hill development, it could not be designed with an accessible crosswalk without extensive grading of the roadway in order to create a flat connection between two streets. Since crosswalks at a roundabout are not at the

A divided Lafayette City Council rejected calls for a conventional signaled intersection and approved the construction of a roundabout at the proposed entrance to the Homes at Deer Hill development in the eastern end of the city.

Northern California-based O'Brien Homes will develop the 45 single-family home project that includes a 10-acre park, a sports field, a 2.9-acre dog park and a parking lot; the roundabout will lie adjacent to the entrance to the dog park.

The council reviewed documents in November that recommended building a roundabout at the Deer Hill intersection but doubted whether it was a smarter solution than erecting a traffic signal. City engineer Tony Coe presented the council further information Jan. 9 confirming that not only will a roundabout be safer and less expensive, it will more easily comply with the requirements of the Americans with Disabilities Act.

While a conventional intersection with traffic signals could be built at the Deer Hill development, it could not be designed with an accessible crosswalk without extensive grading of the roadway in order to create a flat connection between two streets. Since crosswalks at a roundabout are not at the intersection but set back along the approach roadway, Coe said they can be built more quickly and inexpensively in the proposed location because less grading of the roadway would be required.

Speakers praised the roundabout as better for the environment since drivers waste fuel idling at a stoplight, which itself uses energy to switch signals, and presented anecdotal evidence that drivers tend to slow down as they approach a roundabout.

A majority of the council members agreed that the roundabout was a reasonable solution for safety and life-saving purposes, and the motion to approve the roundabout for the future Deer Hill intersection passed 3 to 2.

Council members Mark Mitchell and Ivor Samson, while not vehemently opposed to the roundabout, voted against it because they needed more research on exactly how a roundabout functions as opposed to a traffic signal, and more detail on the incremental cost of grading for a conventional signal versus a roundabout.

Vice mayor Don Tatzin summed up the prevailing sense of the council at the Deer Hill entrance: "It's just not a great location for an intersection," he said.