How your car's 'black box' can show officers if you were speeding before a crash

Officers in New River Valley explain what crash data boxes can show them

By Tommy Lopez - Weekend Anchor / Reporter

DUBLIN, Va. - Even if no one is watching, law enforcement officers will know how fast you were going if you get into a crash. There's a device in nearly every car similar to a plane's black box that records more information than you may think.

Law enforcement leaders in the New River Valley taught officers in training Wednesday about reading crash data boxes.

In car crashes that result in serious injuries, first, officers reconstruct the crash. Then, the box can show them specific information that can provide a complete picture of what happened. Officers say the data holds up in court.

WHAT THE BOX SHOWS:
• How fast the car was traveling at impact
• The car’s speed each millisecond before the crash
• If the car was accelerating
• If the car was braking
• If the driver was wearing a seat belt

WHAT OFFICERS CAN CONCLUDE:
• Which driver is at fault
• If a driver ran a red light
• A driver’s reaction time
• Sometimes: if a turn signal was on

WHAT OFFICERS ARE SAYING
"Once you actually go through and learn how to read and analyze the information that's in that box it's amazing. It's actually mind-blowing to myself, as a reconstructionist,” said Cpt. Daniel Johnson, with the Pulaski County Sheriff’s Office.

Pulaski County deputies pulled boxes out of two cars after a violent crash on Route 11 earlier this month. It helped them understand how a Dublin woman died when another car veered into oncoming traffic.

"Just the knowledge of knowing that information is housed inside the vehicle, if it can prevent or deter somebody from possible leaving without putting their seat belt on, to me, the information is very important,” Johnson said.

Officers don’t just use the information against drivers who will face charges. The data often proves a driver didn’t do anything wrong.

"We've actually had instances where we used the CDR data to actually prove someone innocent even after witness statements stated that they were the ones at fault,” Johnson said.

In one case, data showed a witness was wrong, and a group of teenagers indeed had a green light when a car hit them. Boxes can even show the speed of the other car in a collision. Sometimes specifics like these can provide closure for family members.

"Your loved one was not at fault. Your loved one was not in the wrong. It helps heal up that wound that may have been started by rumors associated with social media,” said Lt. Mark Hollandsworth of the Montgomery County Sheriff’s Office.

Officers do have to get a warrant to look at the data, but they don’t need permission to seize the box. However, anyone can consent to officers looking at a box from their car to avoid the process of getting a warrant.

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