Construction Management

Twin Cities Road Roundabouts at State Route 99 | Galt, CA

City of Galt


Construction Management
Resident Engineering
Construction Staking


ASCE - Community Improvement Project of the Year
CMAA - Project Achievement Awards

Replacing Interchange with Roundabouts to Improve Traffic Flow

The City of Galt’s Twin Cities Road Interchange on SR 99 has seen major traffic growth over the past several years. To keep traffic flowing better both for travelers getting on and off the highway as well as for those trying to move across town, the City of Galt decided to replace two signalized intersections with roundabouts.

The $6.7 million project faced challenges caused by the high volume of daily traffic that had to negotiate detours and the significant community outreach necessary to keep adjacent businesses and residents informed. Components included:

  • extensive staged construction
  • staged removal of traffic signals
  • hot mixed asphalt (HMA) paving
  • curb, gutter and sidewalk
  • landscaping
  • roadway drainage
  • hazardous material handling
  • new SR 99 on-ramp with ramp metering system
  • utility relocations
  • roadway electrical lighting
  • road widening
  • installation of a signalized intersection

Psomas provided resident engineering services, including management of inspection staff and material testing. Additional responsibilities included coordination with Caltrans Oversight Engineers, the County of Sacramento, large retail stores, local businesses, and residents.