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Guidelines for Traffic Impact Studies

Published: May 24, 2016

Roads are a critical public resource and constitute a major investment of the public’s money. Traffic impacts caused by new development – reduction in the traffic carrying capacity of the highways, increased collisions, and traffic congestion – can be very costly for state and local governments, as well as the broader community.

The impact of any proposed development on transportation system performance, whether it is small or large, depends on the number of trips generated by the proposed development, the location of the connection(s) to the transportation system, and the routes taken to and from the site. This impact is quantified by preparing a traffic impact study (TIS).


Traffic impact studies must be conducted in accordance with County standards, as detailed in the Guidelines for Traffic Impact Studies PDF Document.

Download Guidelines for Traffic Impact Studies (PDF, 1.69 MB)