GreenRoad, maker of equipment and software that reinforces safe driving habits, has brought in $15 million in a fourth round of funding to build its customer base and attract partnerships with technology and insurance companies. DAG Ventures led the round, which also included Amadeus Capital, Balderton Capital, Benchmark Capital and Virgin Green Fund.

Based in Redwood Shores, Calif., the company makes a device that you place in a car. It monitors 120 factors like speed, acceleration, braking and merging to identify risky driving behavior. It displays this analysis in the form of green, yellow and red lights that blink on and off. So far, it is predominantly used by vehicle fleets. Because the device beams driving data back to a central web database, fleet managers can easily view which of their drivers are safest and most efficient. GreenRoad claims that this system can reduce fuel costs by 10 percent and car accidents by up to half, according to VentureWire.

The seven-year-old company currently works with 60 commercial fleets, spanning thousands of vehicles. It has raised $40 million to date.