Completion of the Country Park section of Route 3 forms a major part in the Government's strategic road network plan, providing direct access between Hong Kong Island and Kowloon to the northwest New Territories.
The $6.5 billion expressway - additional work at Au Tau has increased the cost by about $250 million - will also help improve freight links between the mainland boundary and the Kwai Chung container port.
The Route 3 (CPS) Company believes journey times between Yuen Long and Kwai Chung will be slashed to just 15 minutes compared to the 30 or 40 minutes it now takes.
And despite the $120 toll for five-axle articulated container trucks, the company believes the savings in time and diesel will more than compensate for the additional levy. Cars and taxis will be charged $15, private/public light buses, light goods vehicles and single deck buses $30 and medium goods vehicles $40.
Running from the northern approach of the Ting Kau Bridge to the Au Tau interchange, the Country Park section consists of the 3.8-kilometre-long Tai Lam tunnel and the Yuen Long approach road.
It also completes the Route 3 expressway that starts in Sai Ying Pun on Hong Kong Island and ends at the junction with Route 2, the northern circular road, which continues to the border at Lok Ma Chau.