Geographical region, sponsoring agency, and the public's view and concerns of generic projects were not predictive of litigation likelihood or EPA rating. A high correlation was found between the level of impacts and both the likelihood of litigation and a poor EPA rating. Therefore, reduction of the level of impacts through feasible mitigation and thorough planning is warranted. Cumulative or net impact scores do not adequately capture the underlying concerns. Models of public's perception of complex multi-attribute projects must include separate factors for positive and negative impacts associated with each dimension.
Duration is a significant factor for describing environmental impacts.
Public perception of a project becomes more negative the more they consider it in detail. People were generally consistent and were able to predict accurately the factors influencing the ranking of complex multi-attribute projects. No single description of the public's preference towards environmental attributes was found. Scoping is crucial to identifying all the attitudes of the public. It must include laypeople, and not just advocacy groups and experts.