The California Department of Transportation (Caltrans) in the US has broken ground on an $86m project to replace the existing Interstate 5 (I-5) / Ortega Highway interchange and boost the traffic carrying capacity of the bridge over the freeway.

The new project will include vital improvements to a major interchange in San Juan Capistrano and create a new gateway to the historic downtown area.

The existing on and off-ramps at the interchange will be widened and a new northbound I-5 on-ramp from the Ortega Highway will be constructed.

The project also involves the realignment of the highway to reroute westbound drivers from Ortega onto Del Obispo Street.

Since 2004, the average daily traffic volume at the intersection has increased from 71,000 to around 100,000.

"The new project will include vital improvements to a major interchange in San Juan Capistrano and create a new gateway to the historic downtown area."

Caltrans director Malcolm Dougherty said that the new improvements will lower congestion at one of Orange County’s busiest traffic chokepoints, making driving much less stressful for motorists.

Expected to be completed within two years, the project is a partnership between Caltrans, the Orange County Transportation Authority (OCTA) and the city of San Juan Capistrano.

It is funded by the State Transportation Improvement Program ($47m), Proposition 1B ($31m), OCTA’s Measure M, San Juan Capistrano ($4m), and Orange County ($4m).

Along with the traffic benefits, more landscaping will be planted to attract more visitors to historic San Juan Capistrano.

Caltrans recently commenced work on a $68m highway widening project that will lower congestion and improve the movement of agricultural goods on State Route 99 in Fresno and Madera counties.

The project is fully funded by Proposition 1B, a transportation bond approved by voters in 2006.