Comprehensive and revealing performance measures are critical for the assessment of long-term investment plans. In this paper are defined three performance measures for long-term investment planning in integrated energy and transportation infrastructures: cost, sustainability, and resiliency. Whereas the first measure can be defined relatively straightforwardly, there exist significant ambiguity and discrepancy in the definitions of the last two in the existing literature. Different qualitative descriptions have been made in various research contexts, yet few studies have provided quantifiable definitions. This paper provides quantitative definitions of sustainability and resiliency measures that are appropriate for assessing long-term investment decisions in an integrated energy and transportation system. Sustainability is defined using the time duration for which the system will be able to satisfy operational and environmental requirements. Resiliency is measured as the cost to transition from a precontingency state to a postrecovery state. A case study using representative U. S. coal transportation and electricity transmission networks is conducted to demonstrate the assessment methods. DOI: 10.1061/(ASCE)EY.1943-7897.0000067. (C) 2012 American Society of Civil Engineers.