If you're new from the Mainland, perhaps you haven't noticed. Or maybe you've lived here so long that you take it for granted. You're not bombarded here by sales pitches whenever you venture outside.

That's because there are no outdoor billboards in paradise. No commercial will spoil your view of the Pacific, Diamond Head or the blue sky. A state law prohibits billboards — and it should stay that way.

In a state dependent on tourism that thrives on Hawai'i's natural beauty, enforcing our billboard ban is important.

Sure, there's still signage, on buildings and company cars. There's so much of that, perhaps you didn't notice the ban's effect. But there's not a commercial billboard among them.

The law, however, has a loophole so big you can literally drive a truck through it— especially if your truck features a large mobile sign advertising any company willing to pony up.

But a billboard on wheels is still a billboard.

Now The Outdoor Circle, protectors of our billboard-free landscape, is trying to stop this form of billboard creep before it gets out of hand. The group has a new proposal before the state Legislature that takes aim at mobile ads and other forms of paid advertising on vehicles.

The proposal rightly doesn't impact companies that advertise on their own vehicles. And it doesn't stop political speech protected by the First Amendment.

The objective is to stop the roving billboards, which are used so effectively on the Mainland to reach captive commuters. Surely, we don't need yet another distraction for motorists already preoccupied with their coffee and cell phones. In a society bombarded with ads, we can do without another commercial interruption.

The challenge with the proposal will be striking the right balance with free-speech rights. It's worth finding that balance if it means preserving the integrity of our existing outdoor billboard ban and keeping paradise commercial-free.