To understand why a **road device** is not an element of temporary signage, it is important to know the different types of signs and devices used on roads.

- **Temporary signage** refers to temporary signs used to warn or guide drivers in specific situations, such as roadworks or changing conditions. Examples of this are **variable message signs**, which display messages that change according to the situation, and **barrier devices**, which are used to block or redirect traffic.

- **Road devices**, on the other hand, are permanent elements of road infrastructure. These include vertical signs that warn of dangers or regulate traffic constantly, such as right-of-way signs or those indicating the presence of dangerous curves. These signs do not change with temporary road circumstances.

Therefore, a **road device** is not considered part of temporary signage, as it is not designed for temporary or changing situations, but to provide constant and permanent information to drivers.