Following outlines the essential components necessary for preparing Traffic Impact Analysis (TIA) Reports in San Bernardino County, in conjunction with the County's established Congestion Management Program (CMP) goals.
TIA Reports must be compiled by a registered professional engineer in the State of California specializing in traffic engineering and signed by the engineer. This requirement applies to land use projects when local criteria and thresholds indicate the need for such reports. TIA Reports must always comply with CMP requirements when a proposed change in land use, development project, or a combination of projects is expected to generate 250 two-way peak hour trips or more. This trip estimate should be based on trip generation rates published by the Institute of Transportation Engineers' Trip Generation or another approved data source recognized by the Congestion Management Agency (CMA). In certain cases, with approval from the City Engineer, Pass-by trips and/or diverted-link trips may be calculated and included when estimating the project-generated trips, using the procedures specified in the most recent edition of the Trip Generation Manual. However, the trucks should be converted to passenger car equivalents (PCEs) before applying the threshold for industrial, warehousing, and truck projects. It is acceptable for the report to adjust the highway capacity manual capacity factors to reflect the increase in heavy vehicles for intersection assessment purposes.
A TIA that incorporates Level of Service (LOS) analysis is mandatory for a proposed project meeting any of the following criteria:
- Any project with initial traffic generation estimates indicating the addition of 250 or more daily two-way trips or 50 or more AM or PM peak period two-way trips to the existing circulation system. Phased projects should be evaluated as a whole, assuming full build-out conditions, to determine the need for a traffic study.
- Any project proposing variations from the standards and guidelines provided in this manual.
- Any project situated within a 1½-mile radius from the project site, in the vicinity of key intersections that currently operate at Level of Service (LOS) D or worse, and where the project's traffic is likely to significantly exacerbate this condition.
- Any project genre more than 40 percent of its total traffic in the form of truck traffic using passenger car equivalents (PCEs).
- Any project intensifying the iterates beyond the level currently permitted by zoning codes, necessitating a Conditional Use Permit, General Plan Amendment, or another discretionary permit.
- When the City Traffic Engineer determines that existing or proposed traffic conditions in the project vicinity exhibit unique characteristics that warrant evaluation.