State departments of transportation and other transportation agencies are struggling with how to integrate sustainability into their investment and operating decisions. In part, this is because there are multiple definitions of sustainability, and they are variously applied at different scales and at different points in system planning and programming; project development, design, construction, and maintenance; and operations. Transportation agencies are incorporating the principles of Context Sensitive Solutions and environmental stewardship into their decisionmaking, and sustainability potentially presents at least a variation and at most an entirely new way of evaluating agency performance. Agencies need assistance in developing sustainability goals and objectives and related performance measures.
Popular definitions of sustainability consider the environmental, economic, and social implications of a decision and the rate of natural resource consumption relative to resource availability and the needs of future generations. For sustainability to be successfully incorporated into transportation decisionmaking, it is essential that these concepts are adequately understood, quantified and applied.
Transportation agencies have strategic goals that cover a broad range of topics, many of which may be consolidated into categories that specifically address the dimensions of sustainability—economic health, social equity, and environmental stewardship.
Examples include improved safety, reduced congestion, wetland conservation, enhanced economic opportunity, improved air quality, reliable mobility, system preservation, accelerated project delivery, economic vitality, ecosystem services, neighborhood preservation, and increased value of transportation assets. Climate change constitutes an emergent and critical area where agencies need immediate assistance.
To achieve the goals of sustainable transportation, agencies require practical and easy-to-use tools or methods to continuously integrate sustainability into current agency performance measurement programs. Working with performance measures, however, can be a daunting task due to the large number of possible measures, extensive data that might be required, and computational complexity—hence the need for identifying useful and easy-to-use performance measures.
The objective of this project was to develop a guide for state departments of transportation (DOTs) and other transportation agencies to use to measure the sustainability of their networks, systems, facilities, projects, and activities, at the appropriate scales, stages (long-range planning, programming, project development, design, construction, maintenance, operations), and time frames. The project will clearly describe the underlying principles of sustainability as they apply to transportation agencies. The guide (1) supports agency decision-making processes at various management levels; (2) enables agencies to develop appropriate sustainability goals, objectives and associated performance measures, and methods for conducting performance measurement and monitoring; and (3) describes computation methods for these measures and possible data sources.
STATUS: The guidebook has been published as NCHRP Report 708 and the accompanying CD is CRP-CD-104. The contractor's final project report that describes the conduct of this research is available here.