Telecommuting can play a big role in cleaning up air pollution, UC Davis researchers have found. A study by graduate students Srikanth Sampath and Somitra Saxena and assistant professor Patricia L. Mokhtarian is believed to be the first empirical evaluation of the emission impacts of telecommuting. They estimate that vehicle emissions in the study were reduced about 70 percent per person on telecommuting days compared to non-telecommuting days. The researchers compared trip diaries of 73 state workers in 1988, before they joined California's Telecommuting Pilot Project, to trip diaries one year later. The diaries showed that working at home reduced automobile mileage from about 50 miles to 12 miles a day per person on the average. Using air quality models, the researchers calculated the emissions savings as 64 percent less total organic gases, 63 percent less carbon monoxide and 73 percent less nitrogen oxides emitted per person for each telecommuting day. The state pilot program became permanent last year and has expanded to well over 1,500 participants, Mokhtarian says. "People are getting more and more confident that telecommuting has a positive transportation impact," she says, "but the question becomes, will enough people do it to make a difference?"