Many state and federal transportation and environmental agencies have signed on to the idea that planning for environmental protection early in transportation system development and improvement is more likely to result in sustainable and less-contentious solutions. We developed a method for Caltrans to use economic valuation methods to improve environmental impacts analysis and project selection. With Transportation Research Board support, we used these methods to analyze future scenarios for a transportation corridor in the North San Francisco Bay Area. We are currently using these methods to develop crediting systems for the Federal Highways Administration and state DOTs.