Well, one issue is that, with most people working in DC, and the polls closing at 6PM, you have to vote before work. I've only lived here for a year so I don't know what the lines usually are at this polling location. It's a densely populated area with many hirise apartments.
Fortunately I don't work in DC, but about 15 minutes away, so I can just drive back this afternoon and vote an come back to work.
I think lines as an indicator have too many variables to determine anything. The line depends on the number of factors, including the machines available, the number of voting decisions, the efficiency of the staff, route changes, and timing. People often come in waves.