If you are discovered placing commercial signs on a right of way, you may be fined. In Florida, for example, it's a second-degree misdemeanor. Fines, up to several hundred dollars per sign per day, vary by county. Many still remember those serial “Burma Shave” signs and their imitators that dotted roadsides decades ago, each with words in a single advertising message inviting travelers to buy a certain shaving cream or visit the local small-town restaurant.
Road signs, especially those not in front of the business being promoted, have become increasingly rare since the mid-1960s, as federal, state and local governments have cracked down on visual clutter and potentially dangerous distractions of drivers. It lasts from a few weeks to a couple of months on average. The law mandated states not only to comply with the law, but also to develop their own standards for certain signs and eliminate illegal signs, or face a reduction in their annual allocation of federal highway funds. In many cases, the city can impose fines on your company for illegally displaying your banner, and claiming it if you remove it can be difficult.