Imagine we needed to evacuate downtown D.C. and Arlington quickly, in the middle of the day. What would be the best way to do that?

We know what wouldn’t work: telling all employees to go home at the same time. That’s pretty much what happened Tuesday after the earthquake. No bridges or roads were damaged, though some traffic signals had switched to flashing red or had lost time synchronization.

Metro ran at 15 mph, causing huge crowds and long waits for those riding. But that couldn’t have much affected the numbers of cars on the road, since anyone who didn’t drive into work wasn’t going to drive back home.

Can our transportation network possibly move so many people at once?

[Continue reading David Alpert’s post at Greater Greater Washington.]

David Alpert is founder and editor of Greater Greater Washington. The Local Blog Network is a group of bloggers from around the D.C. region who have agreed to make regular contributions to All Opinions Are Local.