We missed the formal announcement toward the end of last week that Metro’s board has approved the new S9 Metrobus line, the long-discussed 16th Street rush hour express bus. Metro says it plans to begin S9 service as early as the end of March.

Instead of the more than 80 stops on the S1, S2 and S4 routes between Silver Spring and Federal Triangle or Potomac Park, the S9 will serve only 16 stops between Silver Spring and McPherson Square. Buses will operate every 10 minutes during the morning and evening rush hours only.

The S9s will be the same blue and silver hybrid-electric buses that currently operate on the “Metro Extra” lines, such as those that run along the Georgia Avenue/7th Street NW route.

In a press release, Metro is estimating riders will save only 6 to 8 minutes from their travel times by taking the S9. Doesn’t that seem a little low? We guess there’s only so much you can do about traffic along 16th Street.