Almost half of fleets are measuring emissions, compared with 40 percent in 2009 and 28 percent in 2008, according to an annual survey conducted by PHH Arval. The survey was designed to gauge fleet managers' insights into environmental issues, how fleets are implementing solutions that would reduce their greenhouse gas emissions and more.

Of those fleets that are measuring emissions, 65 percent are using actual fuel data to measure, a more than 10 percent increase over last year.

"Using actual fuel data gives a fleet the most accurate data and accounts for variations in driver behavior (and hence fuel economy) and mileage," the survey report said.

Despite the effects of the economic downturn, fleets are still interested in environmental issues, with 75 percent saying they had been asked about the environmental impact of their fleets in the last year. This is up slightly from 74 percent in 2009. Twenty-eight percent said the economy accelerated their programs, up from 21 percent last year, while it slowed plans of 20 percent of respondents, compared to 9 percent last year.

Sixty-eight percent of fleets said they have an environmental goal for their fleets, up slightly from last year. The top goals included fuel efficiency at 34 percent, and greenhouse gas goals at 31 percent.

"Although an mpg goal is not ideal because it does not account for changes in fleet size or mileage, it does allow a company to track the overall efficiency of its fleet," the report said. "Greenhouse gas reduction goals are the most useful in driving appropriate behavior, as this type of goal allows a company to accurately track its fleet's impact on the environment."

This year, fleets are increasingly focusing on driver behavior as a way to reduce emissions, with 74 percent of fleets reaching out to drivers for their help. The most common type of communication has been to educate drivers on how their behavior impacts fuel economy, with 56 percent of fleets focusing on this, up from 48 percent in 2009.

However, fleets did express some caution in the survey, with 42 percent indicating that cost is a barrier to greening their fleets.

Fleets were also hesitant to adopt new or emerging alternative fuels, including electric, diesel, and compressed natural gas. While conventional gasoline hybrids had the most acceptance, the majority of the fleets surveyed were not even considering such alternatives as biodiesel, CNG, fuel cell vehicles, plug-in electrics and diesel hybrids.