Voter turnout in Salt Lake County could reach as high as 45 percent by the end of the day, County Clerk Sherrie Swensen said.

As of 3 p.m., 16 percent of all registered voters hit the polls. That number will nearly triple with the after-work rush, Swensen said.

"At this rate we're on track for about the same turnout we had in November, which would be excellent for a primary," Swensen said. The November 2007 election had a 46 percent turnout, thanks to the statewide voucher referendum, which attracted heavy voter interest.

Lines have been relatively short. Swensen said the county tried to combat long lines by adding 111 polling places across the county. Now the county has 330 poll locations scattered across the valley.

"I'm glad we did because it takes longer for people to check in," Swensen said. "I just didn't want to have a re-occurrence of what happened in November."

Approximately 23,000 voters cast their ballots before Super Tuesday, through the county's early voting and vote-by-mail programs.