Owning the world's largest vehicle fleet isn't a responsibility Enterprise Holdings takes lightly.

We operate the Alamo Rent-A-Car, Enterprise Rent-A-Car and National Car Rental brands, recognizing that as we have grown, so has our impact on the environment.  We are committed to addressing that impact and sustaining our business for decades to come.

It's a commitment that has driven us to develop a comprehensive environmental stewardship platform that guides our operations and helps bring new technology to our customers. We don't pretend to have all the answers; on the contrary, we view this as a journey.

Along the way, however, we have learned a few things that we hope may be useful to others as they pursue their own paths to sustainability:

1. Align Your Sustainability Strategy with the Overall Mission of Your Business

Our company was founded on a simple philosophy: "Take care of your customers and employees, and the profits will follow."

In more recent years, we've expanded that commitment to include taking care of the parts of the world we touch with our business. The strength of that connection enables us to dive purposefully into issues in ways that make real, long-term sense for our company, such as new automotive technology, alternative fuel research, resource conservation and carbon offsetting. 

2. Play to Your Strengths

One thing that doesn't make sense is for us to tackle an issue that's not connected to our business. Some advice from Michael Porter and Mark Kramer in a 2006 Harvard Business Review article (PDF) really resonates with us: "When a well-run business applies its vast resources, expertise, and management talent to problems that it understands and in which it has a stake, it can have a greater impact on the social good than any other institution or philanthropic organization."

Given the nature of our business, we certainly understand cars and have a major stake in the future availability of vehicles and fuels that are acceptable to society. That has led us to partner with the Donald Danforth Plant Science Center to create the Enterprise Institute for Renewable Fuels, which is making significant strides in alternative fuel research.

3. Embrace the Forces of the Free Market 

It's not enough to develop environmentally responsible vehicles and fuels. These solutions need to be commercially viable as well.

That's why we believe strongly in using our fleet to promote sustainable transportation alternatives and to help advance the market for those alternatives. We call it "the Petri dish mentality."  The latest example would be our plans to add hundreds of electric vehicles at Enterprise Rent-A-Car locations in markets such as Nashville and Seattle beginning in early 2011.

4. Understand – and Anticipate – What Customers Want 

It's not just size of our fleet that matters -- it's about having options that customers want. 

It's no accident that we operate one of the world's most fuel-efficient fleets, with roughly 410,000 vehicles that average at least 28 miles per gallon (MPG), and more than 230,000 that average at least 32 MPG. It's customer interest and demand that led us to begin offering approximately 7,000 hybrid rental options at nearly 100 hybrid branches (PDF) across the country. Listening to our customers also led us to establish a customer carbon offset program for those who want to offset the emissions associated with their rental.

5. Don't Underestimate the Power of Your Employees 

We recognize that our employees are a direct link to our customers, so we keep them informed about our sustainability efforts. 

For instance, we're training employees to educate customers about how to use and charge electric vehicles. It's a two-way street, with our employees keeping us informed of the new options our customers want.