This study investigated the feasibility and limitations of conducting a region-wide cumulative effects analysis of the long range transportation plan (LRTP). Key to a meaningful regional cumulative effects assessment and resource conservation planning is determining when levels of significant impacts to any given resource have been reached.
This study applied a select set of natural and cultural resource metrics to the 2035 long range transportation plans of large, medium and small metropolitan planning organizations (MPOs). A spatial analysis was conducted to calculate the cumulative loss in the distribution of four representative resources from the proposed transportation network and land use changes.
The results generated information about the resource spatial distribution and retention requirements for long term viability. The cumulative effects were measured against quantitative sustainability indicators of high, medium and low risk at which point stakeholders and decision-makers could make a determination of significance of the environmental impacts before the LRTP is complete. An informed decision can be made about the tradeoffs and changes can be made to plan alternatives to create more compatible plans or mitigation to plan impacts can be identified.
The model used for this study is a flexible but robust model that does not impose an undue burden on the department of transportation (DOT) or MPO but it does rely on input from resource agency experts and other stakeholders. Data was readily available in a geographic information system (GIS) format and the process appears viable for most MPOs and partners.