All are remotely controlled; manual route updates are too time-consuming and lack timeliness.
There are two types:
1. Roadside information boards: Highway management units typically have an "Information Monitoring Center" or similar department responsible for unified information dissemination, including LED variable message signs; collecting information from grassroots units and reporting road condition information to leaders and higher-level centers, such as announcements on traffic radio about accidents on highways, or highways operating normally, with the disclaimer "The above information comes from the XX Highway Administration Bureau (Company)"; and transmitting emergency information and dispatching information to various departments within the jurisdiction, such as road administration, maintenance, and toll collection.
2. Information boards set up by individual units, such as toll plazas or service area plazas: These units are responsible for updating the information.