Interstate billboards and local billboards serve different purposes.
An interstate billboard is excellent for reach. It can expose a business to travelers, commuters, tourists, truckers, and regional traffic. This is especially good for hotels, restaurants, attractions, hospitals, colleges, car dealers, tourist destinations, and brands that want broad awareness.
A local billboard is often better for direct community influence. Local boards can reach the same people over and over: parents going to school, workers driving to the plant, shoppers going to town, or homeowners traveling through their own community. For roofers, plumbers, HVAC companies, dentists, clinics, churches, banks, and local retailers, repetition in a local market can be extremely valuable.
The interstate says, “We are big. Remember us.”
The local road says, “We are right here in your community.”
Neither is automatically better. A business that depends on travelers may need interstate exposure. A business that depends on local homeowners may get more value from local roads. A strong campaign may use both: interstate for brand authority and local roads for neighborhood repetition.
The best location is where your customer already drives. A billboard should not simply be in a busy place. It should be in the right busy place.
Best rule: advertise where your best customer passes most often.