If the goal is that all development should never increase road congestion, car-centric, sprawled-out cities will never be able to change.
But by developing at the edges of the city, these developments increase car use, further marginalizing alternate transport methods. Because developers have to pay for any redevelopment of the roads, they favor building in areas that need little change.
The following will refer to traffic impact studies, but apply to traffic impact analyses. The items that typically go into a traffic impact study are: Proposed development land uses, sizes and phasing Study locations, primarily intersections Existing traffic, usually turning movement counts including cars, trucks, pedestrians and bikes, and hose counts Times of days, days of week, and horizon years future years to be studied Expected traffic growth without development Expected nearby off-site developments Crash history The items that are output are: Existing congestion, typically in terms of level of service A-F like in schooldelay and queue lengths Existing queue lengths number of stopped vehicles in lane, typically measured in feet Forecasted congestion and queue lengths Alternatives for addressing the congestion and crash problems, such as: Additional lanes.
They are all traffic studies, but there are other types of traffic studies that are usually done for a governmental agency for their needs. This method also leads to sprawl.
They are usually based on the recommended practice of the Institute of Transportation Engineers.