Six. That's the number of options that still remain in play for new transit options to connect downtown St. Paul with the Minneapolis-St. Paul International Airport and Mall of America.

On Thursday, Riverview Corridor Policy Advisory Committee could narrow that number even further when it meets at 9 a.m. at Union Depot in St. Paul.

The options to improve transit in the corridor includes regular city bus service, a Bus Rapid Transit line or a streetcar on and near West 7th Street.

Here is a snapshot of the six options:

1. No Build: This options would use the existing Metro Transit Route 54 along W. 7th Street and cross the Mississippi River at Hwy. 5. It would have 26 stations and a total travel time of 41 minutes from Union Depot to Mall of America. Projections show 10,700 riders by 2040. The cost would be zero.

2. Arterial BRT: This option would operate similar to the A Line on Snelling Avenue with buses sharing lanes with general traffic. It would have 26 stations along W. 7th Street and cross the river at Hwy. 5. Projections show 11,100 riders by 2040 The cost is $75 million.

3. Modern streetcar: This option would run in a dedicated lane along W. 7th Street or on a track in general traffic. It would have 20 stations and take 44 minutes to make the trip from Union Depot to Mall of America. Options include building a new river crossing bridge at Hwy. 5 or replacing the current bridge. Tracks could tie into Blue Line Tracks at Fort Snelling. The cost would be $1 billion.

4. Modern streetcar serving the Ford site: This options would have vehicles operating in a dedicated lane or on a track shared with traffic. The route would use the existing Ford Parkway bridge to cross the Mississippi River and could tie into the current Blue Line near 43rd Street. The option would require a new tunnel be built at Hwy. 55. The line would have 27 stations, take 56 minutes from Union Depot to Mall of America and serve up to 19,000 riders by 2040. The cost is $1.2 billion.

5. Modern streetcar serving the Ford Site: Similar to option 4, this plan would follow an old Canadian Pacific Railway spur through the former Ford manufacturing site. It would require a new bridge over I-35E between a Canadian Pacific spur and Montreal Avenue, retrofitting the Ford Parkway bridge and a tunnel at Hwy. 55. It would have 27 stations, take 54 minutes and serve up to 18,400 riders by 2040. The cost is $1.2 billion.

6. Modern streetcar with a spur approach but no service to Ford site: This option would use rail vehicles that could run in a dedicated lane or share a lane with traffic. It would not serve the Ford site and would hook in with existing Blue Line tracks near Fort Snelling and Green Line tracks at Cedar Street. It would require a new bridge over I-35E between a Canadian Pacific spur and Montreal Avenue and a new bridge adjacent to the current Hwy. 5 river crossing or replacing the current Hwy. 5 bridge. It would have 20 stations, take 43 minutes from Union Depot to Mall of America and could serve up to 19,600 riders by 2040. The cost is $1.1 billion.

The Riverview Corridor is defined by the Mississippi River on the south, Interstate 35E and Ford Parkway on the north, Lowertown and Union Depot on the east, and Minneapolis-St. Paul International Airport (MSP Airport) and Mall of America on the west.