Two competing approaches now being developed to measure infrastructure sustainability will merge, their sponsors announced Sept. 16. While the link between indexes advanced by the Institute for Sustainable Infrastructure and by the Zofnass Program for Sustainable Infrastructure at Harvard University is expected to boost attention to the rating scheme and save money, it may not win credit ratings for projects, said participants at a sustainability conference in Cambridge, Mass.

The U.S. Green Building Council's LEED rating system has emerged as the leading authority on sustainable building design, but efforts to establish a similar approach for infrastructure across disciplines have failed to gain traction, despite burgeoning demand. ISI Executive Director Bill Bertera and Paul Zofnass, president of industry management consultant Environmental Financial Consulting Group, New York City, and the Harvard program's co-sponsor, expect at least 250,000 public and private sector infrastructure professionals to use the new rating scheme. They also expect the continued endorsement of the American Public Works Association, the American Council of Engineering Companies and the American Society of Civil Engineering, which launched ISI's voluntary rating system called PRISM last May.