Anza Roundabout Project

Contractor Mamco Construction
Construction Start Late February 2012
Construction Completion Early 2012
Work Hours Sunday – Saturday 6 AM – 8 PM
Project Helpline (877) 221-1472

Project Improvements

  • Reconfigure the intersection of Rancho California Road at Anza Road to accommodate a two-lane roundabout.
  • Landscaping installation in the center island of the roundabout.
  • Construct the splitter islands of the roundabout with colored stamped concrete.
  • Construct a Water Quality Basin along Anza Road north of Rancho California Road.
  • Construct an Equestrian Crossing on Rancho California Road east of Anza Road.
  • Add safety street lighting at intersection of Rancho California Road and Anza Road.

Construction Activities


May 17, 2012

End of construction brings removal of temporary stop signs at Calle Contento/Rancho California

Temporary stop signs installed to slow traffic approaching a recent roundabout construction project in Wine Country will be removed tomorrow (May 18) because road work for the project has been completed.

Signs for the four-way stop at Rancho California Road and Calle Contento were installed as a temporary safety measure related to a traffic detour, when the southbound section of Anza Road had to be closed. The roundabout project at Rancho California and Anza roads is complete except for planting that will occur in the next couple of weeks.

Although the four-way stop helped move traffic from Calle Contento onto Rancho California Road, it also caused significant backups on Rancho California Road during peak travel times. During heavy traffic, the backups would cause additional delays for motorists and increase the potential for rear-end collisions on Rancho California Road.

Transportation officials considered retaining the signs and conducted a study to determine if that choice was warranted. The study concluded that daily traffic volume on Rancho California Road averages about 12,000 vehicles per day at Calle Contento, while the daily traffic volume on Calle Contento is less than 1,000 vehicles per day at the intersection. In comparison, daily traffic volume on Anza Road at Rancho California is 4,000 vehicles per day.

Officials also determined that sight distance is ample for motorists on Calle Contento to enter Rancho California Road, and noted that left-turn and right-turn  lanes are provided on Rancho California Road. In addition, based on observations and field experience, the California Highway Patrol has recommended that the signs for the all-way stop should be removed.

The roundabout was fully opened on May 4 and traffic is flowing smoothly and without delay, a departure from traffic patterns before the project began. In an effort to retain Wine Country’s rural nature, a roundabout was chosen in lieu of a traffic signal to ease traffic congestion at the intersection.



May 8, 2012

All-Way Stop at Calle Contento

The all-way stop at Calle Contento will be removed on Wednesday, May 16 by county staff. The intersection will be restored to two-way stop control (stop signs on Calle Contento) with Horse Xing warning signs at the intersection on Rancho California Rd.

Questions on this matter can be directed to Dennis Green at (909) 800-0451.



May 4, 2012

Anza Roundabout is Now Open

The Anza Roundabout at Rancho California Road and Anza Road, is now open as of 2:00 PM today, Friday May 4th. Anza Road south is also now open to traffic.

Over the next couple of weeks, punch list work will continue with occasional flagging taking place as necessary.

The project is on schedule to be completed in early June 2012.



April 30, 2012

Project Update

Traffic continues to be diverted to the north side of Rancho California Road at Anza Road as crews flag motorists through the the project 24 hours a day. On Friday May 4, 2012, the contractor is expected to fully open the roundabout to two-way traffic. Flagging will continue on an as needed basis to allow construction equipment to be moved safely in and out of the work area.

Access to Anza Road south from Rancho California Road is also scheduled to open on Friday May 4, 2012.

The contractor is in the process of making modifications to the roundabout. Landscaping is being planted in the approaches to the roundabout and in the center raised portion in order to prevent headlight glare from oncoming traffic.

Motorists are encouraged to slow down and obey flaggers’ directions as the project enters the final construction stages. The project remains on schedule to be completed in June 2012.



April 20, 2012

Rancho California Road to be Narrowed to One Lane for Both Directions of Traffic at Anza Road

On Monday, April 23, traffic on Rancho California Road at Anza Road will be shifted to the north side of the road in order to allow construction crews to perform work on the south side of the road. The traffic shift will require Rancho California Road at Anza Road to be narrowed to one lane for both directions of traffic from Monday, April 23 to Tuesday, May 1. Access to Anza Road south from Rancho California Road will continue to be closed during these nine days.

Flaggers will be on site night and day to direct traffic safely through the work area.

The following detour to access Anza Road south of Rancho California Road is in place:

  1. South on Calle Contento from Rancho California Road
  2. East on Pauba Road to Anza Road

These closures are part of the Anza Roundabout Project. We thank you for your patience while this necessary work is performed.

April 18, 2012

UPDATED: Closure on Anza Rd between Rancho California Rd and Los Nogales Rd beginning April 16

Anza Rd south of Rancho California Road will be closed on April 16th for approximately three weeks (weather permitting). Please see the detour map below.

Rancho California Rd will remain open to two lanes (one lane in each direction) with the exception of nine (9) calendar days when Rancho California Rd will only have one lane of traffic open for both directions. During these nine (9) calendar days, the County’s contractor will be working 24 hour shifts.

Click here to view detour map

Roundabout Information

Project Handout Project Information (side 1)
Roundabout Information (side 2)

Anza Roundabout Photos