Which method is NOT typically used for communication of service changes by the CTA?

The communication of service changes by the Chicago Transit Authority typically involves methods that are direct and accessible to riders. While the website updates, signs at stations, and announcements on vehicles are all standard practices for informing customers about changes in service, television advertisements are not commonly used for this purpose.

The CTA primarily relies on its website to provide real-time updates and detailed information about service changes. Signs at stations are crucial for immediate visibility to riders who are currently using or waiting for service. Similarly, announcements made on vehicles ensure that passengers are informed during their ride. Television ads, although they can reach a wide audience, are not an effective or timely means of delivering immediate updates on service changes, as they do not target commuters in real time or provide information when and where it is most needed.