Many drivers don't realize they have to move over or drop their speed when passing a police car on the shoulder. The results when they don't were captured in an unbelievable dash-cam video of his accident.
Trooper David Avila's traffic stop on June 14 started the same way, but ended in a horrific accident.
A tractor trailer driving too close to the shoulder slammed his police cruiser and then hit the state trooper.
"I guess I heard the rumble strip just before the vehicle came across or came towards me, took a quick glance over my shoulder and kind of saw it and thank God," says Trooper Avila.
He made it to the railing before collapsing.
Since then he's been taking physical therapy for injuries to his shoulder, back and legs. He also has post-concussive syndrome; he can't balance and light hurts his eyes.
"Sometimes I look at it and it just doesn't seem like the light is at the end of the tunnel, but I'm able to walk. Doing a lot of physical therapy to get back," says Avila.
The driver who hit him broke the "move over" law. It's there to protect emergency responders.
The law says drivers must drop their speed ten miles under the speed limit or pull to the left lane when they see an emergency vehicle on the shoulder, but many drivers either don't know about the law or they aren't obeying it.
The truck driver paid a fine for breaking the law, but the officer he hit is paying a much higher price.
"It affects not just the officer and their families, but it's also for protection, for everyone," says Avila.
Doctors aren't sure when Trooper Avila will be able to fully move his right arm again or return to work.