The concept of "green" has been ill-defined for the fleet industry, making progress towards reduced environmental impact difficult to track. Thus far, benchmarking against internal goals or external baselines largely has been impossible. However, environmental performance doesn't have to be difficult to track.

Leading fleets track their "greening" progress by measuring greenhouse gas (GHG) emissions, the leading factor in human-caused climate change. Vehicles are responsible for about a quarter of U.S. greenhouse gas emissions.

Insuring Performance

The ACE Group, a leading global commercial property and casualty insurance and reinsurance organization, has worked at length to reduce its GHG footprint. A member of the U.S. EPA Climate Leaders program, ACE committed to reduce its GHG emissions by 8 percent per employee from 2006 to 2012. The ACE 175-vehicle fleet was included as part of this goal.

ACE uses metrics representing total GHG emissions and average vehicle mpg. ACE's fleet management company, PHH Arval, provides access to fuel consumption and total GHG emissions data through the PHH GreenFleet program.

ACE also tracks average observed vehicle fuel economy through vehicle mileage and fuel consumption data. The company has set a stretch goal of a 30 mpg average in 2012, representing a 40-percent improvement from its baseline.

"Our average vehicle mpg metric is a simple way to monitor our progress in providing ACE employees with the tools they need to reduce their environmental footprint," said Melissa DeGennaro, environmental analyst for ACE. "It's also a direct metric of something that we can control."

Tracking Progress

U.S. Foodservice (USF), a foodservice distributor, has also been leading the way in tracking and reducing environmental impacts from its fleet. From 2007 to 2008, USF reduced fleet emissions by more than 4 percent through such fleet efficiency improvements as reducing idle times through driver training and automatic idle shutoff, installing maximum speed controls on vehicles, and investing in technology solutions for more efficient delivery truck routing.

"Our drivers are on the road 365 days a year, delivering high-quality food and related products to over 250,000 customers, including restaurants, hospitals, hotels, schools, and governmental operations," said Mike Frank, SVP of operations at USF. "Quality and timeliness are critical to our customers. That's why we select fleet metrics that focus on efficiency and productivity."

USF measures gallons of fuel consumed per ton of product moved. Linking environmental performance to efficient product movement was key. With a good fuel data collection process, USF calculated gallons consumed, but the weight of product moved was more challenging. Like many companies, USF tracks cases of product moved. However, since the composition of product cases can change over time, this metric is not an ideal environmental performance measure.

"USF came up with an innovative solution to the vexing problem of tracking product weight. Weighing a representative sample of product annually and developing an annual average case weight allows for better year-over-year comparisons and benchmarking with other leading fleets," noted Tom Murray, managing director of corporate partnerships at Environmental Defense Fund, which worked with USF on its efforts.

It's All About the Data

Quality data is vital to track environmental performance. Both ACE and USF collected fuel consumption data, critical for calculating GHG emissions. The combustion of fuel produces emissions. Fleets can calculate CO2 emissions by multiplying gallons of fuel by the fuel-specific carbon dioxide co-efficient. For example, each gallon of gasoline directly emits 19.4 lbs. of CO2 when burned. Carbon dioxide accounts for about 95 percent of greenhouse gas emissions from passenger vehicles.

Translating product case data into tons, USF developed a stronger long-term metric. ACE tracked overall performance and performance related to its fleet mpg; both allow comparisons over time.

Using consistent and comparable units is key in tracking environmental performance. The most common unit used to measure GHG emissions is metric ton. It is also important to be clear about which emissions fleets track. While CO2 is the easiest GHG to quantify, full GHG accounting from vehicles requires tracking emissions of methane, nitrogen oxide, and refrigerants.

The following summary outlines seven fleet environmental benchmarking metrics. Given their multifaceted nature, an individual fleet may want track progress by following a series of metrics.

About the Author

Jason Mathers is corporate partnerships project manager for the Environmental Defense Fund. He can be reached at (617) 406-1806 or by e-mail:


Total Greenhouse Gas Emissions

The total amount of emissions is the best measurement to assess overall environmental impact.

Minimum data requirement: volume of fuel (by type) consumed. The EDF-NAFA calculator can estimate non-carbon dioxide GHG emissions from this data. Unit: metric ton.

Greenhouse Gases Per Ton of Freight Moved

This cargo-based metric quantifies the efficiency of moving goods. By using tons rather than pallets or cases, fleets ensure their metrics are consistent internally and comparable externally.

Minimum data requirement: total emissions and tons of freight moved. Unit: kilogram.

Greenhouse Gases Per Miles Traveled

Miles traveled is a leading factor determining vehicle emissions. It's tough to compare the performance of units or peer entities that have different mileage patterns. This metric allows fleets to consider mileage, thus enabling comparisons between these groups. Derivatives of this metric include greenhouse gases per specific mileage quantity (e.g. 100 miles or 10,000 miles) and emissions per kilometer.

Minimum data requirement: total emissions and total miles. Unit:  kilogram.

Greenhouse Gases Per Vehicle

This metric represents the average performance of a particular unit or company-wide vehicle fleet. It is influenced by factors including fuel source, miles traveled, and fuel economy. Fleets willing to take a "deep dive" into their data can produce similar, unit-level metrics that will help track the performance of individual operators of same models and identify units that contribute most to the company's overall GHG footprint.

Minimum data requirement: total emissions and number of vehicles for total fleet average. For a vehicle-specific number, unit-specific fuel consumption data is required. Unit: metric ton.

Cost Per Metric Ton of Greenhouse Gases Reduced

Different emission reduction strategies imply different costs. Some advanced-technology vehicles require more capital up-front. Driver training courses, routing software, and telematics all typically have costs associated with them.

Fleets can compare their "greening" progress in seeking the most cost-effective strategies for reducing emissions by collecting emissions and cost data.

Minimum data requirement: expenditure difference between an emission reduction effort and a baseline case, including capital expenses (and savings) and operating savings; total greenhouse gases reduced from baseline. Unit: U.S. dollars spent per metric ton of greenhouse gases reduced.

Percentage of Fleet Vehicles Emitting GHG Benchmark Levels Per Year

The greenhouse gas per vehicle metric previously described is important to assess the average fleet performance. However, for diverse fleets, GHG per vehicle data can fail to tell the full story.

The percentage of fleet vehicles emitting certain levels of GHG emissions metric aims to examine changes in the population of different fleet segments. According to a Greener World Media report, "State of Green Business 2009", in 2008, the average fleet vehicle emitted 15.1 metric tons of greenhouse gases.

Using this metric, fleets can determine what percentage of their individual fleet performs better than the average fleet vehicle. By using further benchmarks, such as five and 10 tons, fleets can track the evolution of their fleets toward lower emission vehicles.

Minimum data requirement: vehicle specific fuel consumption. Unit: metric ton.