Almost every municipality in Colorado, excepting Pueblo, bans portable signs. Code enforcement is usually quite tough, and street spam in the Centennial State is quite rare.
Most municipalities around Orlando ban portable signs, although they are still seen in unincorporated areas where code enforcement is lax. Street spam is, sadly, very common here, and I have a "zero tolerance" policy in my town -- same day removal, and the police have orders to escort sign posters to the city limits.
El Paso, Texas, allows them on a "temporary basis, not to exceed three hundred and sixty five days a year." No kidding. El Paso, and most other Texas cities, are very "sign friendly," so it's to be expected.
The trend in most parts of the United States, though, is towards outright prohibition of portable signs, both on a temporary and permanent basis. My observation has been that portable signs are far more common in Canada than in the United States, although in the decreasing number of American cities that permit them (El Paso), they are usually EVERYWHERE. OTOH, billboards in rural areas are a blight on the United States landscape; in Canada, they are relatively rare.
