Motorcycle Safety Site

Lock-Step Synchrony is Bad Form
(Be a traffic shock absorber)

By: James R. Davis

With a great deal of attention being paid to various hurricanes in the gulf area over the past couple of weeks I have been thinking about evacuation problems and, of course, what we might learn from them as motorcyclists.

It seems a stretch, I know, but there really is some relevance. Consider, for example, the danger to you of a rear-ender - not just the cell-phone talker who fails to realize that traffic is stopping ahead, but the every-day Joe who happens to accelerate just as traffic begins to slow down. If you are the vehicle ahead of him, you are the most likely to get hurt.

So it seems to me that driving in lock-step synchrony with traffic ahead of you just might be a significant cause of problems behind you, and that, in turn, becomes YOUR problem.

Let me explain. Traffic around you, ahead and behind, is moving at 35 mph. You have a 2-second gap between you and the vehicle ahead of you. That vehicle, for whatever reason, begins to decelerate. So, too, should you, of course. In the process you will find that your gap is somewhat less than it was because it took you a moment to realize and then react to the slowing car ahead. Just how much shorter a gap should you allow?

The answer, as we all know, is still 2-seconds worth. Well, I'm not quite so sure of that. It may well be that you want to allow that gap to narrow just a bit more than 2-second's worth,because that leading vehicle may well reverse the deceleration trend and regain its original speed - the slow down was an anomaly, a slight variance that quickly disappears.

If you allow that gap to get a bit smaller, that means that you did not slow down as much as did the vehicle ahead of you - and neither did all the vehicles behind you.

What you have done is smooth out the flow of vehicles. Maybe a dozen vehicles behind you did not slow as much as the vehicle ahead of you, and potentially hundreds of following vehicles didn't have to slow down at all.

Naturally I do not mean to imply that you place yourself into a dangerous situation and ignore the fact that your gap is getting shorter. Not at all! But because you are then aware of the slowing down you no longer have a built-in delay of any meaningful duration that will get in the way of your reacting to what the vehicle ahead of you does next. If it decides to stop, so will you. If it continues to decelerate as it had been doing, so will you. It's just that you did not remain in lock-step synchrony with that leading car's behavior, and as a result, neither did all the vehicles behind you.

When the vehicle ahead of you begins to accelerate, so should you - but not as quickly! Allow your gap to get wider than you would normally want and close it up later, when traffic is moving smoothly again.

In essence, if you refuse to behave in lock-step synchrony with traffic ahead of you, you have introduced a shock absorber into the flow of traffic. The more drivers who act like you do, that is, the more shock absorbers there are in the system, the smoother traffic flow will be for all, and that translates into fewer - by far - rear-enders.

I made a case for vehicles that are all moving at about the same speed, but the biggest payoff of this methodology is when they are moving (or not) at vastly different speeds.

Consider driving on surface streets noticing that traffic ahead of you has stopped for a red light. I suggest that you begin slowing down long before you get up close to the vehicle ahead of you (and then must stop yourself), and gradually approach that vehicle as you eat up time. In some (often many) cases you will find that the light has turned green and vehicles ahead of you have begun to move before you have had to stop yourself, so that you can then merely continue on your way, accelerating as necessary to regain or attain a 2-second gap.

Again, you have acted as a shock absorber. Again, all the traffic behind you has smoothed out. And again, your odds of being rear-ended has been diminished by your actions.

Lest it has not occurred to you, this is a specific recommendation for behavior when group riding!

(I hasten to add that your gasoline mileage has improved and your brake pads will last longer.)

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