MOUNT PLEASANT — Just before the attendance bell rings, the roads around the biggest high school in the state swarm with travelers racing to a beehive of classrooms.

In the afternoon, when the school day is over, the pattern reverses itself as more than 3,000 Warriors hit the highway.

“It’s nightmarish,” said former Charleston County School District Board of Trustees member Larry Kobrovsky, whose daughter graduated from Wando High.

Some relief from the daily traffic snarl is on the way in the form of a new mile-long road under construction behind the school. It will connect a roundabout at Park Avenue Boulevard and Carolina Park Boulevard with Darrell Creek Trail, which runs to U.S. Highway 17.

“It ought to flow much better,” said Jeff Scott, school district director of security and emergency management.

Finding a solution is critical because Wando is probably second only to North Charleston’s Boeing campus in terms of commuter congestion, he said.

The new road can’t come soon enough for Chris Marino, director of the Children’s Center at Carolina Park, which is located close to the school on Carolina Park Boulevard.

“It’s really jammed up out there in the morning. Most of my parents have learned to avoid that 8 a.m. to 8:30 a.m. time period because there are a lot of high school kids,” he said.

The afternoon rush is the same.

“Trying to get out of here when school gets out, it’s very dangerous because they drive so fast,” Marino said.

On Tuesday morning, cars jockeyed for position in the U.S. 17 North outside turn lane that leads to Carolina Park Boulevard and a right turn into Wando. Traffic in that lane was backed up more than 100 yards.

The inside left turn lane from the highway to the boulevard, which requires a merge to the right before turning into the school, was nearly empty.

Some impatient drivers unwilling to queue up at the back of the outside turn lane beat the system by racing to near the front of the line and cutting into it.

“We’ve been up there watching for that. We haven’t seen anything grossly out of order. Anytime you change a lane, you have to be safe in order to do so,” said Police Sgt. Kim Herring, traffic division commander.

Despite the crush of cars, no one seemed to mind that some people were breaking into the outside turn lane. There were no angry honking horns or raised fists that indicated school travel etiquette had been breached.

“You’ve got almost 4,000 kids going to that school so traffic is going to be bad. Most of the time we’re assisting buses getting in and out, and if we see congestion we try to relieve it,” said Sgt. Stan Gragg, police department spokesman.

Traffic is expected to intensify as hundreds of residences are constructed in the long-awaited Carolina Park development near the school. Plans call for 1,500 single family homes, multifamily dwellings and a retail and commercial area similar to Park West.

The developers of Carolina Park are building the new road behind the school that will connect to Darrell Creek Trail.

It is an extension of Park Avenue Boulevard, which currently provides a way to the school from S.C. Highway 41. The new part of the boulevard is expected to open for traffic in November, Scott said.

Reach Prentiss Findlay at 937-5711.