Election officials around the country are nervously planning how to avoid long lines at the polls this year, after voters waited for hours at some Wisconsin sites earlier this week. That came after voters in Maricopa County, Ariz., had to wait up to five hours last month, in part because the county cut back on the number of polling sites. Those delays led to raucous protests at the state capital and a voting rights investigation by the U.S. Department of Justice.
This year's unusually large voter turnout in the primaries has caught a lot of people by surprise, according to Tammy Patrick of the Bipartisan Policy Center in Washington, D.C.
"I think most election administrators worry about this, and are staying awake at night thinking about it," she said.
Patrick is a former Maricopa County election official, who also served on a presidential commission appointed after the 2012 elections to try to eliminate long lines at the polls. She's now working with election officials across the country to help them do that, and says one challenge is that voting can be unpredictable.
"You're never sure what you need to plan for. So what you need to plan for is to be able to turn on a dime, and try and mitigate any issues that can arise," Patrick said.
In Arizona, the surprise was that thousands of voters showed up at the polls who weren't registered with a particular party and were therefore ineligible to participate. They were offered provisional ballots instead, which take a lot longer to cast, and slowed down the lines.
Many election officials are taking all this as a sign to be ready for whatever comes, and to beef up resources where they can.
Neal Kelley, registrar of elections for Orange County, Calif., remembers emergency measures he had to take in 2008 when a political rally was held at a local university shortly before polls were set to close on Election Day.
"There were thousands of students that attended, and then they said, 'Go vote.' And this was 7 at night maybe? Suddenly the polling places on campus were overrun," he recalled.
He sent in what he calls a rapid deployment team, which quickly set up additional voting machines. Kelley says these teams will definitely be on hand for his state's June 7 primary. He's also doing something else the presidential commission has recommended — encouraging residents to vote early or by mail to lighten the load on primary day. And he's conducting mock elections with county employees to help identify potential bottlenecks in advance.
"We'll do time studies on how long it takes them to get from the door to the official table, from the official table to the booth, and from casting the ballot out of the polling place," Kelley said.
Many election officials are looking at more sophisticated ways to manage crowds, similar to those used by businesses like Wal-Mart and Disney. Some offices will be monitoring lines throughout the day so they can post expected wait times online.
And MIT political scientist Charles Stewart has been helping officials use an online tool that allows them to manage lines by plugging in a few key variables: "how many people are going to show up during a period of time, how long it takes to take care of them on average, and how many places do you have to take care of them."
Stewart said you can then figure out how much equipment and personnel you need at which polling sites, to keep the lines moving.
Of course that's easier said than done, given limited budgets for most election offices.
The Montgomery County Board of Elections in Maryland recently used the new online tool and found it could run into problems at some sites in the April 26 primary, if it doesn't make adjustments.
"If we expect a turnout of 1,500 voters at that polling place, we need to make sure we have two scanners, or we're going to see lines in excess of a half-hour," said Deputy Director Alysoun McLaughlin.
Right now, most sites in the county are set to have only one scanner to count ballots, so her office is looking for more funds to get extra machines. It could be especially important in this county, which has a whole new voting system this year. It replaced its touchscreen voting machines with paper ballots that need to be filled out with a pencil.
Patrick said that's another thing election officials have to take into account: how much new voting systems and new rules, such as ID requirements, might slow voters down.