A federal appeals court has upheld an agreement between Michigan and Canada to build a second international bridge in Detroit. The 2012 deal was challenged in federal court by the Ambassador Bridge company. The private business owned by the Maroun family operates the only existing bridge across the Detroit River that connects the US and Canada. The Sixth Circuit US Court of Appeals dismissed all of the bridge company’s claims that the agreement violates federal and state laws, and the US Constitution. Construction on the new bridge is expected to begin next year.