The promise of free admission to Six Flags Over Georgia created a massive traffic jam during the morning rush hour Thursday on nearby Interstate 20 and surrounding roads.

Cars began lining up as early as 3:30 a.m. for the offer. The "Ditch Work" promotion offered free admission to the amusement park between 6 and 9 a.m.

Traffic began backing up in both directions on I-20 before 5:30 a.m. Some drivers let passengers out of their vehicles to walk along the interstate to the park.

Those pedestrians, many of them children, wanted to get in line at the park entrance, but Six Flags workers turned them away, telling them admission was limited to people in vehicles. That caused even more problems when those walkers began trekking back to their vehicles, wandering on the interstate searching for their rides.

There were reports of fights near the park's front gates.

Once Six Flags officials opened the parking lots at 5:30, they filled up quickly. Park officials decided to end the free admission promotion at 5:55 a.m.

A representative of Zoo Atlanta told WSB-TV that it was swamped with families all day and that they were thanking Six Flags.

Zoo officials believe so many people were turned away from the amusement park that they looked for an alternative way to spend the day.