Maryland officials are considering six possible designs for upgrading busy Route 3 in western Anne Arundel and northeastern Prince George's counties - a road where traffic is expected to increase 70 percent by 2025.

Designs for the highway were displayed last week. The state is studying a 9-mile stretch of the highway from U.S. 50 to Route 32 and is seeking public comment. Officials have met with a 15-member focus group during planning.

The proposals:

Boulevard alternative: Includes three through lanes in each direction and auxiliary lanes or shoulders. An overpass would connect Route 450.

Main-line improvements: Addition of a third through lane northbound from St. Stephens Church Road to Route 32 and southbound from Route 450 to U.S. 50. Separate traffic on Routes 3 and 450. Overpass at Crawford Boulevard.

Modified boulevard: Overpasses at Davidsonville and Waugh Chapel roads.

Additional interchange option: Signaled intersections to separate main line Route 450 from main line Route 3. Would provide free flow between Routes 3 and 450.

Minor construction: This option includes improving intersections and adding auxiliary lanes. Car pooling and other ways of reducing traffic would be encouraged.

No major improvements, but minor short-term improvements would occur as normal maintenance.

The project - the most expensive proposal has an estimated cost of up to $475 million - will most likely be funded by state and federal funds, said Christopher Weber, the project manager.

The state is aiming to start work in 2006. Five to 21 properties could be taken for the project, he said.