Organizers of a program in Denver, Colorado, that tracked drivers’ behavior remotely and provided online summaries of poor driving habits like speeding announced on Tuesday that participants reduced their carbon-dioxide emissions by 10 percent per mile traveled.

The 400 participants became less likely to accelerate and stop quickly as they became smarter about their driving habits. Idling alone decreased by 35 percent, savings that could amount to hundreds of thousands of dollars a year for a fleet of 2000 vehicles, organizers said.

The program “provided the world with an important insight on how biofeedback and the Internet can be combined to tackle greenhouse gases,” said Lawrence Goldenhersh, CEO of San Diego, California-based Enviance, which provided the Internet-based emissions management system.

About 30 percent of Denver’s total carbon footprint is attributed to vehicle emissions.

Driving Change was launched in March 2008 as a 12-month pilot project. Denver-based Cartasite provided the telemetry technology for sending data about drivers’ behaviors to Enviance’s tracking system. And Denver-based EnCana Oil & Gas underwrote the program.

The project was the first time venture-backed Enviance applied its tracking system to vehicles. The startup has built a customer base among the oil and gas, chemical, pharmaceutical, and utility industries by providing Internet-based environmental, health, and safety compliance tracking solutions.