Cities that are looking to expand their town with new housing or business developments, or private contractors that specialize in gated or planned communities will often turn to city regional and town planners to help with the design of their building plans. City regional and town planners study things such as population density, traffic patterns and local history to devise a building plan that will benefit the city the most. Private contractors building planned communities will often have a city regional and town planner involved with every step of the process, so their new community has a unique look all to its own and is well organized.