This resource paper summarizes the continuing research needs in the area of wetlands, wildlife, and ecosystems in their relationship to transportation activities. Although there has been a great deal of progress, these needs continue to be similar to those expressed at the last Environmental Research Needs in Transportation Conference in 1996. Adequate impact evaluation tools still need development and testing on transportation projects. Techniques to measure the quality of ecosystems and associated biota need to be developed and tested. The effectiveness of mitigation or compensation for impacts should be evaluated. Furthermore, the effectiveness of programmatic approaches in accomplishing environmental and regulatory goals, while showing great promise, still requires thorough evaluation.