The National Highway Traffic Safety Administration is investigating the Ford Freestyle wagon for complaints that it surges forward at low speeds.

More than 200 complaints have been lodged about the issue, alleging that the Freestyle jumps forward at low speeds even when the accelerator isn't pressed.

NHTSA is investigating about 170,000 Freestyles in model years 2005 through 2007. So far, 18 crashes have been attributed to the issue, with only one minor injury, according to the agency.

The incident happened in a residential driveway when a customer's knee was bruised by the lunging car. Reports indicate the lunges may get worse when the air conditioning is on or when the steering wheel is turned sharply, NHTSA said.

Consumers have reported the problem in both forward and reverse gears.

Ford says the lunge can be stopped by applying the brakes. But the vehicle can move as much as 10 feet if the brakes are not applied, are applied late or are lightly applied, according to the company.

"We will fully cooperate with the government as they review this matter," Ford spokeswoman Susan Krusel said.

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