There is a tiered bell schedule in U-46, which allows one bus and driver to provide transportation service to three or four schools every morning and afternoon. Due to the tiered bell schedule, and to ensure that students do not arrive at school too early, drivers may need to wait a few minutes between dropping one group of students and picking up the next group of students. In most situations, it is more efficient for the bus to remain out in the district for a few minutes, than it is for the driver to return to the transportation facility between routes. The bus driver will usually try to find a parking lot or side street near the starting point of his or her next route to wait. (Drivers refer to this time period as "lay-over" time.)