Tennessee's offer to test residents around the state regardless of their coronavirus symptoms drew massive crowds on Saturday.

Hundreds of cars were lined up before sites opened in Robertson County, Madison County and Williamson County, almost immediately pushing projected wait times beyond the windows when the testing centers were to be open.

By the end of the day, more than 6,500 residents were tested at the 20-plus drive-thru sites statewide, including Robertson, Williamson, Wilson, Rutherford, Dickson, Maury and Montgomery counties.

That single-day test total would exceed the number of tests state labs have conducted since the outbreak began: Of the 90,000 tests processed in Tennessee before Saturday, state labs accounted for about 5,500 of those.

Gov. Bill Lee announced on Wednesday that the free tests would be available to give Tennesseans better access to testing and make informed decisions as the state looks to reboot Tennessee's economy in the coming weeks.

Demand was high.

The Robertson County test site was scheduled to open at 11 a.m., but opened early with the long line.

In Jackson, hundreds of cars were also reported lined up across the parking lot of the fairgrounds. The line formed before the testing site opened at 8:30 a.m., as police officers managed traffic wearing masks and gloves. Health professionals were also covered from head to toe with a face-shield over their eyes.

Eleven test center sites were scheduled to be open on Sunday and will include Sumner County from 9 a.m.-noon, at Gallatin High School, 700 Dan P. Herron Drive, Gallatin.

There has been contingency planning for sites to open early or stay open later if lines warranted, Flenor said.

Tennessee Department of Health Nurses and Tennessee National Guard medics are performing the tests that will be conducted with a nasal swab, Flenor said.

Test results are expected to take around 72 hours, though it could be longer depending on volume, according to Flenor.

Those wanting to be tested do not have to be a resident of the county, Flenor said.

Davidson County and Shelby County, where the majority of the state's confirmed cases are located, did not offer public test sites for asymptomatic residents. Nashville does have three test sites for the coronavirus, but requires people meet certain criteria to be tested.

The state's expanded testing effort will also be available during the weekends of April 25-26 and May 2-3.

Reach Andy Humbles at ahumbles@tennessean.com or 615-726-5939 and on Twitter @ AndyHumbles.