According the an article in the Washington Post,
[E]arly voting, by mail or in person, is becoming more common and is likely to account for one-third of all votes cast in the November elections, up from 14 percent in 2000, predicts Paul Gronke, a researcher with the Early Voting Information Center in Portland, Ore.
I just applied for an absentee ballot to avoid long lines. I also will avoid getting into a car accident on the way to the polls. An excellent ORMS Today article by Alexander S. Belenky and Richard C. Larson addresses the issues relating to voting queues for the curious operations research analyst.
A large number of absentee ballots doesn’t necessarily mean that voting lines will short on Election Day. A report released by American University’s Center for the Study of the American Electorate (CSAE) forecasts that this election may have the second highest turnout ever. (The figures in the report are created with Excel and illustrate why one shouldn’t use Excel for technical reports. Yuck!).