Three more states are considering legislation to control access to cars' black box data as law enforcement and insurance companies become more aggressive in their acquisition and use of the information.

Black box you say. What's that?

If you don't know there is a black box in your car recording your driving habits, it's time you found out. If your car is equipped with airbags it's also equipped with a black box.

The function of an event data recorder -- or EDR -- is to deploy the airbags in an accident. But wait there is more. Much more. The EDR collects a lot of information that it uses in deciding when to fire the airbags.

The continuing concern is that drivers do not have access to the information collected in their cars' black boxes, or even know their cars have the devices, but insurance companies and police departments can access the data to use against drivers following accidents.

In Iowa, a handful of state police are trained to access the black box data following an accident.

Trooper Greg Salier is one of four people on the Iowa state police force trained to use a computer system to investigate accidents.

When Salier plugs a car's EDR into his computer system he can find out how fast that car was going in the seconds before an accident, if the car was accelerating, on the brakes, and if the driver and passenger were wearing seatbelts.

"It's something else that helps me prove what happened in addition to proving it mathematically, through witness statements, through physical evidence, through the damage on the vehicles," Trooper Salier said.

"Sometimes I get a full 150 milliseconds during the deployment phase, sometimes I get a full 5 seconds prior to the collision," he said.

Critics argue that insurers want easy access to black box data so they can use the information to set rates, to reward good drivers and penalize the bad ones and fight big claims.

The automobile insurance industry also claims black box data can aid in proving fraud cases that eventually go to court.

The controversy is just the beginning. Technology already exists that would allow more information to be recorded about a driver's acceleration and steering.

An enhanced black box could record the time and date of an accident and, using cell-phone technology, relay life-saving information to emergency crews.

In Massachusetts, Pennsylvania and Virginia, state legislators are debating who can have access to the information currently available in an EDR and what those people are going to be allowed to do with the information.

North Dakota last year put some limits on insurance companies making your car testify against you. The legislature decided that insurance companies will be barred from using data from a vehicle's black box to set drivers' premiums.

Some privacy minded lawmakers in Massachusetts want to ensure drivers have more control over black boxes in their cars.

"I feel there has been an erosion of civil liberties in this country and I feel this is another one of the Big Brother things in our lives," said bill sponsor David Torrisi, a Democrat from North Andover, Mass.

Torrisi's bill would prohibit the release of the data unless the vehicle's registered owner consents, a court orders the release, the data is used to improve safety and the driver's and owner's IDs are not revealed, or a vehicle dealer or automotive technician needs the information to work on the vehicle.

Insurance companies are opposing Torrisin's bill because, they insist, the boxes help reconstruct accidents accurately.

State Rep. Ted Harhai pushed a similar bill through the Pennsylvania House of Representatives at the end of January. That bill is now in committee in the state Senate.

The measure would also require that vehicle owners' manuals inform buyers in Pennsylvania that the devices are present.

The Pennsylvania bill states that anybody who wants access to the information stored on the EDRs must get either the vehicle owner's permission or a court order.

The Virginia legislature, which recently banned the use of red-light cameras on privacy grounds, is just beginning to debate the black box issue.

Since the 1970s, the federal National Highway Traffic Safety Administration (NHTSA) has been using the data from the EDRs to gather statistical data about car crashes. NHTSA spokesman Ray Tyson estimates that 65 percent to 90 percent of all new vehicles have the boxes.

When people learn of the existence of EDRs, Tyson said, they sometimes mistakenly conclude that the boxes do the same things airplane black boxes do, such as recording extended periods of time or even conversations that take place.

NHTSA is supposed to issue a new rule later this year requiring automakers to standardize black-box technology so data is recorded and stored the same way for researchers to compare.

The new NHTSA rule that is due later this year is certain to insure that automobile black boxes and their future is a hot topic.