Final answer:
The sign signifying the short state highway within a city or urban area is known as a route marker, which helps identify and navigate specific state routes.
Step-by-step explanation:
The sign that tells you what road you are on and is a short state highway in a city or urban area is known as a route marker. This type of sign is used to identify specific highways and is typically accompanied by a number which denotes a particular state route. Different from a milepost marker, which informs you of the mile on the highway where you are located, or an exit sign, which indicates where to leave the highway, or a guide sign, which can provide various types of information including directions to towns or services. Route markers help with navigation by informing drivers of their current route and can also help with trip planning.