Nearly 20 years ago, one lane in each direction of a 12-mile stretchof the Santa Monica freeway in Southern California was reserved during peak traffic hours for "high-occupancy vehicles." Ridership in car pools increased 65 percent and almost tripled in buses. However, the diamond lanes experiment, as it was known, was prematurely ended after less than six months due to public outrage and derisive news commentary. But attitudes have changed, according to UC Davis researchers who recently consulted some 1,000 urban Californians. People are more receptive to the idea of converting a mixed-use freeway lane into a car-pool lane than previously believed, says engineering graduate student John Gard, who completed the study for his master's thesis and presented the results at a recent meeting. Lane conversions were less resented than such painful driving disincentives as monthly parking fees or bridge and turnpike tolls. In one surprising result, people cited financial savings as the biggest car-pooling incentive.