The start of ticketing ends a 30-day period when only warnings were issued to violators. The cameras will operate 24 hours a day, photographing every red-light runner, police said.
Each violation will be reviewed by the Alexandria Police Department before a ticket is issued, police said.
The cameras are located at the following intersections:
•South Patrick Street and Franklin Street
•South Patrick Street and Gibbon Street
•Duke Street and South Walker Street