The Wakefield Eastern Relief Road stretches for 4.6 miles (7.5km) between the A642 and A638 and crosses the River Calder.
The road could help to reduce congestion and pollution within the city, Wakefield Council said.
A development of 2,500 homes east of the city centre is planned to be built around the new road.
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Councillor Peter Box, leader of Wakefield Council, said: "It is one of the biggest and most ambitious projects that this district has seen for decades."
Work on the road started in April 2015.
A Â£33m relief road using the first new river crossing in Wakefield for more than 100 years has opened.