Maryland Gov. Larry Hogan has announced a $9 billion plan to widen Interstate 270, the Capital Beltway and the Baltimore-Washington Parkway in the suburbs of the nation's capital.

Hogan said Thursday the work on the three major state highways will reduce congestion for millions of drivers.

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The Hogan administration is calling the plan to add four lanes on both I-495 and I-270 the largest proposed public-private partnership in North America. The state will be seeking private developers to design, build, finance, operate and maintain the new lanes on I-495 between the American Legion Bridge and the Woodrow Wilson Bridge and on I-270 between I-495 and I-70.

The plan will have new express toll lanes, in addition to existing lanes, on I-495, I-270 and Maryland 295.