Optima has successfully worked with the following companies and organizations:

• Alaska Department of Transportation
• Arizona Department of Transportation
• British Gas Corporation
• California Department of Transportation
• Central Hudson Gas and Electric Corporation
• City of Beijing
• City of Detroit
• City San Francisco
• Con Edison of New York
• Dominion (Ohio)
• Dominion (Pennsylvania)
• Federal Highway Administration
• The Gas Research Institute
• The Gas Technology Institute
• Kansas Department of Transportation
• KeySpan Energy Corporation
• Long Island Lighting Company
• Ministry of Communications, Saudi Arabia
• Ministry of Public Works, Portugal

• Minnesota Department of Transportation
• New Jersey Natural Gas
• Niagara Mohawk Corporation
• North Carolina Department of Transportation
• Oklahoma Natural Gas
• ONEOK Corporation
• Pacific Gas and Electric Corporation
• Public Service Electrical and Gas
• Road Directorate of Portugal
• Rochester Gas and Electric Corporation
• San Diego Gas and Electric
• San Francisco International Airport
• Transportation Research Board of the National Academies
• U.S. Department of Energy
• Urban Institute
• Vermont Department of Transportation
• Washington Department of Transportation
• The World Bank