"The law is that you have to drop 20 miles below the posted speed limit or vacate the lane next to the emergency vehicle. Emergency vehicle is going to be a patrol car or a firetruck, or an ambulance. As you can see people coming down the freeway at us, I've got my lights on like you're being pulled over right now and none of these cars are really slowing down or vacating the lane."
About two hundred yards farther up the freeway is another patrol car. Starting today, the officer in the second car will check the speeds of motorists when they pass the first squad car, which most likely would be involved in a traffic stop. If the driver doesn't switch lanes or slow down enough, the second officer will stop them and give them a warning.
"We're going to do nothing but issue warnings, and verbal warnings and hand out cards. One side of the card will be in English, the other side in Spanish. We won't be writing citations for this initiative the first week. But then the following week we won't be issuing warnings anymore."
As we do the interview on the middle shoulder of the the freeway, Balthrop points out the numerous drivers who are breaking the law, even Metro bus drivers.
"Even in rush hour traffic as you can see they're still not attempting to vacate the lane or slow down. I do think most people know about the law I just think most people aren't thinking about that when they're driving down the road."
Without a second patrol car, the law can be difficult to enforce. After all, an officer isn't going to stop in the middle of issuing a ticket just to go stop another vehicle to give that driver a ticket. But Balthrop says the goal of the warnings and the law itself is to keep everyone safe.
"Every time that we make a traffic stop, that's the first thing on our mind is to get back in the car safe, and to have the violator be able to move away safe, and for no accidents to happen. It happens real quick. We've got an officer in the hospital now that was hit by a tire that came off a trailer and rolled down the freeway and hit him."
So they plan to spend all week making the public aware of the law they say can save lives.
"See, he decided to get over but he waited too long. So he's slowing down a little bit, but that's not forty miles an hour.
Bill Stamps, KUHF News.