By Russ Horton of the Texas Tribune

Nearly two-thirds of Americans now own smartphones. More and more are getting their news from social media rather than the morning newspaper. A fifth of the nation’s onetime cable subscribers have now “cut the cord” in favor of online streaming services, and the ride-hailing app Uber has been valued as high as $68 billion.

Without a doubt, we are now living in a digital age.

Roadside billboards are following the same technological trend. Digital...