OTTAWA (AFP) - The United States and Canada are planning to build a second bridge connecting the US city of Detroit with Ontario's Windsor, to ease congestion at North America's busiest border crossing, news reports said Thursday.

Media here reported that the new bridge would be the largest joint construction project ever undertaken by the two countries.

Public broadcaster CBC, citing unnamed sources, said the five-billion dollar (Canadian, US) span would be built alongside the current Ambassador Bridge, which crosses the Detroit River and links the US heartland state of Michigan to Ontario. A 15-kilometer (nine-mile) freeway will also feed the new link.

The CBC said an official announcement is expected in July.

Critics have said the Ambassador Bridge, built in 1929, is too narrow to handle increased traffic between the world's two biggest trading partners.

More than 25 percent of merchandise trade between the United States and Canada crosses the current four-lane suspension span, which is traversed by some 10,000 trucks each day.

LIKE IT?  LET OTHERS KNOW