[This post has been updated. An earlier note that said the Key Bridge is no longer structurally deficient was incorrect. It is the 14th Street Bridge that has been rehabilitated.]

2:20 P.M. Update:

ARL Now points us to another march that could add to commuting issues on Thursday: Occupy Northern Virginia, a group that hopes to march from Ballston to the Key Bridge, according to the schedule on the group’s site.

This march, which would begin at 3:30 p.m. and meet up with the other march at 5 p.m., could cause traffic issues on Wilson and Clarendon boulevards before heading north on Fort Myer Drive in Rosslyn. (The group was kind enough to post a map on their site, so if you commute in the area you can just check out the map to see what roads to avoid.)

Follow the State of NoVa for more on this.

3:20 P.M. Update: Metro warns that some of its bus customers may be affected by the march. Those routes include 31, 32, 36, 38B, 42, 43, D5, D6, H1, L1, L2, the S lines, and the X lines.

Original Post:

Since they began last month, the Occupy D.C. protests have occasionally caused some traffic problems. This could occur again on Thursday afternoon and into the evening, as a march from McPherson Square to the Key Bridge could snarl traffic along the way.

The march, one of several planned to celebrate the two-month anniversary of Occupy Wall Street, should go from 2:30 to 6 p.m., according to OccupyDC.org’s schedule.

Figuring out the exact timing of when and where the march could cause traffic issues is tricky. There’s a Facebook invite listing the event as from 3:30 to 6:30 p.m., a tweet listing the march as at 4 p.m. and an Our D.C. posting mentioning the Key Bridge rally at 4:30 p.m. Our D.C. tweeted that the rally will stick to the sidewalks and not block traffic. But a press release sent out earlier in the week noted there would be a “human chain” crossing the bridge.

In other words, we can’t give you an exact idea of where and when to avoid driving. Our best bet is that you should try not to drive through the area between McPherson Square and the Key Bridge between 2:30 and 6 p.m. — and it would probably be best to avoid planning on taking the Key Bridge immediately after 6 p.m.

It’s entirely possible the marching masses could stick to the sidewalks, cause zero traffic problems and have no impact on the evening rush. But when a large group of people plan walking across a stretch of the city, the drivers, bicyclists and pedestrians that would normally commute need to be prepared.

Try to plan on using an alternate route: If you normally take the Key Bridge, maybe head south to the Memorial Bridge. If you normally bike east on M Street in Georgetown, maybe head north to P or O streets before heading east. If no alternate route works, think about staying at work a little later to avoid the traffic jam.

They’re heading to the Key Bridge because it’s a “vivid example” of infrastructure needing repair, according to the OccupyDC event listing. A report last month included it among the 215 structurally deficient bridges in the Washington region.