Editor’s note: This is the third in an occasional series on Manteca traffic.
They slow traffic down.
They keep traffic moving.
They make it easier to cross streets and enhance safety near schools and parks
They discourage through traffic in neighborhoods.
They avoid traffic signals that can cost as much as $500,000 per intersection.
In short, roundabouts could be the answer to avoiding a number of future traffic problems in Manteca.
Virtually every new neighborhood in the planning process has a requirement for roundabouts either adjacent to future schools or parks or deployed in a manner to slow traffic on the main access street.
They are also being pondered for use at some intersections on the proposed McKinley Expressway that will eventually be Manteca’s southern most thoroughfare swinging from the current terminus of McKinley Avenue at Woodward Avenue in southwest Manteca and eventually to a new interchange on Highway 99 midway between Ripon and Manteca.
The use of roundabouts would allow the city to not just keep traffic moving while slowing it down enough to allow access from connector streets but it would also go toward meeting a mandate of the San Joaquin Valley Air Pollution Control District to reduce vehicle idling. The more time vehicles have to stop at traffic signals or stop signs, the less efficiently they burn carbon-based fuel which in turn impacts air quality. Idling vehicles are a major source of valley air pollution.
There are already three roundabouts in place in Manteca. Two are in the Tesoro neighborhood in the triangle formed by Atherton Drive, Van Ryn Avenue, and Woodward Avenue in southwest Manteca. Each is located on entry streets to the neighborhood that would have in the past simply T-intersected with the street next to a school site and a neighborhood park. Instead there are roundabouts.
The other is on Buena Vista Drive north of Woodward Avenue. It is the largest roundabout in the South County. It covers an acre and was large enough for the placement of a small park in the middle.
It was designed to discourage through traffic from Woodard Avenue to reach future commercial along Atherton Drive. That segment of Atherton Drive between Main Street and its current terminus just east of Wellington Avenue is targeted to be constructed this year.
Also, all roundabouts built in new neighborhoods as a condition of development are landscaped.
The city also has roundabouts on it existing list of traffic calming devices to address traffic problems in existing parts of Manteca. It isn’t, however, on the initial list of options to consider.
Ripon has incorporated a number of roundabouts through the city including in new development as well as in existing neighborhoods where traffic was increasing due to growth.
Traffic is the focus of a 501-page document the Manteca Planning Commission will conduct a public hearing for on Jan. 25. It involves traffic standards and goals that will impact the lives of every Manteca resident for years to come.
The document is the environmental impact report for the circulation element to Manteca’s general plan that serves as the city’s blue print for growth.
It addresses acceptable levels of service - how long it takes to get through key intersections at heavy traffic times - plus explores expressways to move traffic quicker, ways of slowing down traffic in neighborhoods, ways of softening the visual impact of streets, plus ways for pedestrians, bicyclists and even transit riders to get around Manteca.
In cobbling together such a report, planners must take into account that actions can’t take place in one location without impacting another. Such is the case with proposed changes in downtown traffic.