The sign "movable bridge" indicates that there is a bridge in the vicinity that can open to allow ships to pass. When you see this sign, it is important to be alert because the bridge may close suddenly, which can affect traffic.

Drivers should be prepared to stop and wait if the bridge is in the process of opening or closing. There may also be additional signs indicating the specific regulations regarding the timing of the bridge operations. Always pay attention to any signals or lights associated with the bridge to ensure safe passage.

If you have any further questions about this sign or other traffic rules, feel free to ask!