ORR Safety Chat - Driving Reaction Time
A complete safety mindset is something that stretches across your workplace behaviors, personal life, and everything in between. OSHA regulations and company procedures guide you while at work, but when you leave it's up to you to carry this same mindset through your hobbies, everyday actions, and family activities. Driving is one of those activities we do everyday but pay little mind to how dangerous it can be. In the video below, ORR Safety Specialist Phil Aldridge discusses how long it really takes for you to stop your car.
Hey there, my name's Phil and today, I'd like to have a little safety chat with you. As some of you know, I used to be a police officer in southeast Los Angeles County. One of the worst days of my career was the day I handled a traffic collision between an 18 wheeler and an 8-year-old boy on his bicycle. It was pretty bad, as bad as it sounds, so as you can imagine, traffic safety's pretty near and dear to my heart.
Today, I want to talk about reaction time and specifically, I want to talk about how much distance you'll cover before you can safely brake in time to avoid a collision. I'm going to use a couple different speeds; 40 miles an hour and 55 miles an hour. There's a lot of different information out there and a lot of different studies have been done. I'm using the Utah Department of Transportation facts and figures. There are a couple different ones that kind of hedge one way or the other, but they're all basically the same. It's a really good rule of thumb and I think you'll be surprised at just how far you go before you're able to stop in time to avoid a collision. So, we're going to go ahead and take some measurements and use these cones that I borrowed from work. We're going to get a nice visual representation of just how far you'll go before you can stop in time. I'm going to go ahead and turn the camera around and we'll get started here.
Minimum Safe Stopping Distances
Alright, this is the view from my steering wheel. You can see a couple landmarks out here in the field. Just think for a second, if you were going 40 miles an hour or 55 miles an hour, how far into this field do you think you'd get before you could safely brake in time to avoid a collision? I've already measured it out, so I'm going to go throw down some cones and we're going to go check it out. I'll be right back.
Alright, I am back and let me just tell you, it is hot outside. Let it never be said that I don't suffer for my heart. Anyway, let's talk about what these cones mean. That first cone that I put down, it's just off to the right, closest to the soccer goal. That's 124 feet away. That is the minimum distance that your car would travel before you're able to stop in time to avoid a collision. That's taking into account your reaction time, a controlled deceleration. That's the minimum distance that a normal family car would travel.
Safely Stopping a Big Rig
The cone off to the left, the last one I put down, that's 169 feet. That's the minimum distance a big rig would travel if it was going 40 miles an hour and needed to stop to avoid a collision. If you're driving a bigger and heavier truck, it's going to take you longer and you're going to cover more distance in order to safely decelerate if you see a hazard in the road.
Safely Stopping a Normal Car
That last cone, in the middle, way out in the distance, the one with the white stripe, that's 225 feet away. That's the minimum stopping distance for a normal car traveling 55 miles an hour, so again, this is perfect conditions. This is if your reaction time is flawless, you're not fiddling with the radio, you're not on your phone, you're not yelling at your kids, you're not just lost in thought, wondering how it all went wrong. That's if you are totally focused on driving, totally engaged with what you're doing and it's a perfect day; it's not raining, there's no oil on the road, there's nothing changing the friction on the road.
Human Reaction Times are a Huge Factor
If everything is perfect and going your way, these are the minimum stopping distances based on average human reaction time. I've been reading some studies that are coming out of the U.K. that think the average human reaction time is probably double what governments think that it is. These facts and figures that we're getting from driver's training or the Department of Transportation might be really low-balling it compared to what it really is for a human being in real world conditions.
So that's it from the driver's perspective. I wanted to give you kind of an idea of how far it would look from a driver's perspective but I think you won't really be able to appreciate it until you see it all in a line, horizontally, so I'm going to get out of the car and we're going to take a nice wide angle so you can see just how much distance you'd be covering before you could safely stop. I'm just going to hop out of the car here and I will be right back.
Visualizing the Distances
Alright, had to come out pretty far so you could see this, but there's my car over there. There's the first cone, 124 feet. That's the minimum stopping distance at 40 miles an hour for a regular car. There's 169 feet in the middle there. That's the minimum stopping distance for a big rig at 40 miles an hour and there's a 225 feet minimum stopping distance for a normal car going 55 miles an hour. As you can see, it's a pretty good distance; more than you might think, and again, that's on a perfect day. That's you with perfect reaction time, no oil on the road, no water on the road, and you're totally paying attention to what you're doing. That's how far you would travel minimum. Best case scenario.
There's one more related issue that I want to talk about and that's the idea of a visual horizon. You see that driveway that's right in front of my car there? The end of that driveway is about 30 feet in front of my front bumper. Would you believe most people, when they're driving around, that's kind of where they focus on, is right at the end of that driveway there. Most people, their eyes just kind of lazily drift down and that's basically where they stare as they drive around.
Where Should Your Eyes Be Focused?
That's not a great spot to stare if you are trying to maximize your reaction time. We're talking about minimum stopping distance. That's minimum if everything is perfect. The weather is perfect, the road is perfect, your tires are perfect. You are perfectly engaged in what you're doing. You're not fiddling with the radio, you're not on the phone. You're wired and ready to go and ready for anything but that's just not how we drive. We drive to the same places day in and day out. We drive the same routes day in and day out and we get complacent. We don't expect anything bad to happen and that's why we get surprised. One way we can minimize that is to maintain a much higher visual horizon as we're driving around.
Don't stare 30 feet in front of your car. Stare way down the road. Where you see that house in the distance there, that's where your eyes should be hovering because that allows you to see more of the road. You can see more of the driveways, more of the angles, and it gives you much more time to react. You don't want to test your brakes, you don't want to test your tires. You want to give yourself as much time as possible, so by maintaining a higher visual horizon, you maximize your chances. You give yourself the best chance of avoiding something bad happening as you're driving around. Anyway, these are just some tips from me to you. As you guys are driving, I hope you make it a safe day out there and I will talk to you next time.