This study has looked at how U.S. transportation agencies have applied engineering economics (benefit–cost analyses and similar procedures) to decisions on highway investments. State departments of transportation (DOTs) are most likely to use economic methods when considering investments in pavement and bridge preservation, safety improvements, and major projects on trunk lines and in urban areas. This study, however, has found agencies that use economic information across their key business and decision processes. Information was gathered through literature review, presentations at conference committee meetings, a screening survey of state DOTs, and interviews leading to case studies.