Actually, I think much of outdoor advertising is quite tasteful and interesting and not at all "pollution." As far as roadside advertising, I think it should keep words to a minimum (one doesn't need to read War and Peace while zooming down a highway!) and rely on interesting art, photography, and design: words merely being the clincher.
I think that there are many billboards which are created that are completely useless. Most of them, it seems like, are made with the print medium in mind, and whomever designed them neglected to put much thought into the fact that someone was going to be whizzing by them at 45 mph or more. Duh!
But yeah, there are, in some places. far too many of them....much like the pics you posted.
Billboard advertising is worthless unless you have other venues that bring the visual to "top of mind" such as radio, print, electronic, etc. When used in conjuction with other forms of advertising and for a single purpose/campaign, it can be very effective. Without this, it's just another "pretty picture".
