Q: Regarding the tolls on I-85, three people in a car is a toll-free car. How is this verified for billing purposes? I’ve also seen drivers entering the lanes illegally, crossing the solid lines. How does the monitoring equipment detect that, and are they ticketed?

— Dan Siegel, Dacula

A: The Georgia Department of Public Safety monitors the lanes for occupancy enforcement by receiving daily downloads from the State Road and Tollway Authority back office, SRTA spokeswoman Malika Reed Wilkins told Q&A on the News in an email. The downloads, refreshed every few minutes, show accounts that have designated their status as toll-free, meaning they will have three or more passengers in the vehicle when using the Express Lanes. When a vehicle designated as toll-exempt/free comes through in the Express Lanes, noise alerts the officer in his vehicle, and the vehicle's license plate is displayed on the officer's laptop. The motorist runs the risk of getting pulled over by law enforcement and being issued a citation, Wilkins said. There is technology in the lanes --  gantry controlled access -- that detects when a vehicle enters and exits the lanes at the dashed white lines. The system is designed to generate a violation notice to the vehicle's owner if the Express Lanes are not entered or exited properly, Wilkins said.

Andy Johnston wrote this column. Do you have a question about the news? We’ll try to get the answer. Call 404-222-2002 or email q&a@ajc.com (include name, phone and city).