Have you ever wondered how far you can push something? Perhaps you had an idea that wasn't accepted by everyone and you kept pursuing it because you thought it was right. Maybe you were warned that you were pushing it too far. As you continued your pursuit of your idea, you may even have considered just how far is far enough.
"As we consider how far is far enough, we must remember to keep three times and distances in mind."
How far is far enough is something we should also consider as we ride. Specifically how far is far enough to ride behind the vehicle ahead. We must have enough room to be able to stop if that leading vehicle stops. Obviously our speed will be an important factor in determining that distance. We also need to consider the components of the distance required for stopping.
Recognition time is the time required for us to see a situation developing that requires us to stop. This time can vary greatly depending on what we're doing at the moment. If we are aggressively scanning our environment, we may be able to quickly identify a problem as it occurs. If someone walking down the street or an unusual billboard or the scenery around us distracts us, we will not see the problem as quickly. If our vision is impaired by spray of rain or the glare of the sun or the traffic around us, it will take longer to recognize the need to stop. Fatigue and other impairments can affect our ability to process what we are seeing and realize we need to stop.
Once we recognize we must stop, it takes some time for us to physically apply the brakes. This is Reaction time. We must roll off the throttle, reach for the front brake lever as our foot moves over the rear brake pedal. Once in position, our right hand and foot can begin applying both brakes. Typically it takes three-quarters to one second for us to move to the brakes and begin the stopping process. This time can be longer if we are using a throttle lock and our hand is not on the bars or our foot is on a highway peg.
Now the brakes and the tires must do their work. We call this Response time. As the calipers squeeze the pads against the rotors slowing the wheels, the traction between the tires and the road must scrub off our speed and bring us to a stop. Worn brakes, old tires, or wet roads will reduce our bike’s ability to slow as quickly.
Recognition time, reaction time and response time are accumulative. They add up, they don’t overlap. At sixty miles an hour, we are traveling eighty-eight feet a second (44 ft/sec at 30 mph.) Extend any of these times and our total stopping time and distance are increased. So how far is far enough behind the vehicle ahead? How far can we push it? Maintaining a distance that allows us to address the three components of stopping and adjusting for things affecting them may keep us from becoming the bumper sticker that extends someone else’s recognition time.
Ride Smart! Ride Safe!