Nothing herein shall be construed to affect in any way any directional, informational, or street name signs erected by any municipal, county, state or federal government agency or utility in connection with street identifications, public buildings, railroad crossings, electric utility lines and installations and other like uses, buildings or activities or any nonilluminated nameplate or plaque of less than two square feet in area or any directional signs on premises less than three square feet in area indicating traffic movements, exits and entrances.