Telecommuting seems to be living up to its promises when it comes to its impact on travel, energy use and air quality, according to UC Davis researchers. For each person who works at home instead of traveling to work, about two gallons of gas are not burned, 26 miles are not driven and the air is slightly cleaner, according to a review of studies of eight public and private telecommuting programs recently presented at a national transportation meeting. Contrary to some predictions, nonwork travel has not increased, and so far telecommuters have not moved farther away from work. Telecommuting means bringing the work to the employee at or closer to home as a substitute for the employee traveling to work. This trendy commute alternative -- which, combined with home-based businesses, is now as common as mass transit in some metropolitan areas -- was boosted last year by two White House reports aimed at increasing government efficiency and decreasing greenhouse gas emissions. "The weight of evidence is pretty strong that telecommuting is a useful strategy for reducing peak-period travel," says UC Davis professor Patricia Mokhtarian, who directs a $2.8 million California telecommuting research project.