Patterns are changing because of the pending construction of a new indoor aquatic center on campus, 708 W. Park Ave.
The $21.5 million project hasn't yet begun because all the permits aren't in hand. The goal is to finish in spring 2019.
The traffic changes are expected to be in place for the next two school years.
Students, parents and bus drivers must follow the new traffic flow starting Aug. 14, the first day of classes. Employees must follow the new flow starting Aug. 7.
In the new configuration, the main campus road at Dawes Street should be used in the morning only by buses and parents dropping off students. In the afternoon, parents picking up students can use this gate. Bus drivers will use it, too.
Students and employees parking on campus can leave campus using the main gate in the afternoon.
An east entrance at Sunset Drive and Linden Lane should be used in the morning only by students and employees parking on campus.
Parents should not drop off students at this entrance in the morning, nor on nearby neighborhood streets, officials said. Warning signs will be posted in the neighborhood, and they'll be enforced by Libertyville police.
That east gate will be used by students and employees leaving campus in the afternoon. Parents can use the entrance to pickup students in the afternoon.
The school also has an entrance on Route 176 west of the main entrance, but that road will be limited to construction traffic. A west-side exit for cars leaving campus and going west on Route 176 is being created.
Finally, student drop-off will be allowed on the east side of Dawes Street between Route 176 and McKinley Avenue. State law prohibits students from being dropped off or picked up on Route 176, and violators will be ticketed by police, officials said.
"This is very dangerous and, for that reason, illegal," District 128 spokeswoman Mary Todoric said.
District 128 officials know it's going to take time for people to get used to the new flow.
"There will be problems at the start, just like with anything new," school board member Ellen Mauer said. "As soon as we see what the issues are, we can work those out."
To reduce delays during drop-off and pickup times, officials are urging students to take the bus, carpool, or walk or ride bicycles to school if they live close enough and the weather is favorable.
Departing for school earlier than in past years also is recommended.
"Don't roll out of bed and expect to get there the same time you did last year," Mauer said. "It is going to be difficult."