Construction work on the Doyle Drive replacement project began with the first of four tunnel excavations being carried out in the US state of California.

The project will replace the 73-year-old Doyle Drive southwest of the Golden Gate Bridge to make
travelling in and out of San Francisco safer and easier.

The new access to the Golden Gate Bridge involves six lanes and a southbound auxiliary lane of new roadway for 1.5 miles.

Other works include construction of an interchange and replacing a bridge in California for structural sufficiency.

The billion-dollar highway project will be financed by 12 different funding sources, including the American Recovery and Reinvestment Act (ARRA), and is scheduled to be completed in 2013.

ARRA is providing $129m, including $83m in formula funds allocated toward the current tunnel excavation, and a $46m ARRA-funded TIGER (Transportation Investment Generating Economic Recovery) grant.