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Judging the size of a gap

To some, a “gap” is that opening that appears in front when a button pops off your shirt. Anybody remember “Fatstuff,” the Hawaiian character in “Smilin’ Jack?” Nah, you’re too young. To others the Gap is a place to buy fancy clothes. To me a gap is a space between other vehicles that I want to move into or through.

Not allowing sufficient gap is a really dangerous thing to do and a very common cause of collisions. I don’t need to tell you how tricky this can get in our larger, heavier vehicles or when we’re towing something. So, how do we accurately judge the size of a gap?

Picture this: You are in your car waiting to cross a two-lane street from a standing stop. On average it takes about five seconds to cross that street. “Is that all?” you ask. But, we’re not talking about 1-2-3-4-5 here! We’re talking “one-thousand-one, one-thousand-two, one-thousand-three, one-thousand-four, one-thousand-five.” That’s a long time. And, this is just a two-lane street.

What if it’s a multiple lane street you are crossing with four lanes or six? Add a half hour or so. No, just kidding, but we are talking about big chunks of time to do these things without creating a dangerous situation. And, that’s where so many of us go wrong. We get impatient, don’t give ourselves enough time to safely execute these maneuvers and crashes result.

Imagine now that you’re turning right at that intersection and accelerating to just 20 miles per hour. For the average car and driver this takes about six seconds. One-thousand-one, one-thousand-two, one-thousand . . . okay, you get the picture. The nearest oncoming car should be a half block or more away for you to safely execute this maneuver. In your motorhome or pulling your toy hauler allow at least three times as much time and distance.

Now you’re turning left and accelerating to 30 miles per hour in your car. This takes even longer, about seven seconds on average. Again, we’re talking about substantial chunks of time. If cross traffic is traveling at 55 miles per hour and you’re turning left and joining traffic, the nearest car coming from your right should be more than three blocks away in order for you to execute that maneuver without “causing another driver to take action to avoid a conflict with you” which is DMV talk for a dangerous action which is cause for failing the license test.

Again, add much more time and distance if you’re driving or hauling your rig.

A lot of factors can change the dynamics and therefore the size of gap needed. The experience and condition of the driver, for example, reduced traction, the width of the intersection, the speed of cross traffic and of course the type of vehicle you’re driving will all make a difference when judging the size of the gap needed.

When should we look for a gap?

  • When entering traffic from a standing stop.
  • When crossing an intersection.
  • When making a turn onto another roadway.
  • When changing lanes.
  • When merging onto a high speed roadway like a freeway.

Here’s an old saying I just made up: “If you don’t know . . . don’t go!” Don’t let yourself be intimidated by the clueless jerk behind you. Oh no! It’s the dreaded NASCAR wannabe again! You know who I mean. He or she has been tailgating you for a couple of blocks doing the things that clueless jerks do when they’re in a big hurry to get nowhere like shrugging their shoulders and looking exasperated or drumming their fingers on the steering wheel.

The other day the girl behind me, a pretty, well dressed young lady from whom one would not expect such behavior, surprised me with the one-finger salute when I slowed to yield the right of way to a driver coming from my left at a roundabout. I guess she thought I should drive right out in front of traffic.

Think of it this way: If you cave in to the intimidator and move into the intersection before knowing it’s safe and then something awful happens, it won’t be the intimidator in the intersection when the world comes crashing down, it will be you! The intimidator, now pronounced “terminator”, will be down the road, out of there and could care less what happened to you. Hasta la vista, baby!

Don’t let intimidators force you into bad driving decisions.

One very tricky place to look for a gap is when merging onto a freeway. Next time you are on a freeway and passing an on-ramp, watch what drivers do as they attempt to enter the traffic lanes. If it wasn’t so dangerous it would be comical. Most act as if they are entitled to a gap and that it will magically appear for them without effort and when needed. They are forgetting some important fundamentals that every drivers ed kid knows.

The responsibility for safely merging onto a freeway belongs to the driver doing the merging. Those already in a traffic lane have no responsibility whatever to make life any easier for you if it’s going to put them in danger. After all, would you attempt to move over and make room for me if you have a semi alongside? I don’t think so!

The main responsibility for those already on the freeway is to maintain a constant speed so a merging driver can judge the gap. Most drivers come down that ramp like they’re all alone in the world. If they bother to signal or head check at all, it will be at the last minute when it’s too late.

Here are the three steps to remember for safely entering a freeway:

  1. Signal early! Do it as soon as you get on the ramp. “Hey, everybody, I’m here, I’m moving down this ramp and I’m getting ready to invade your space so pay attention!”
  2. Head check early and often! Mirror checks too but not exclusively. That’s not good enough! Head checks! That’s when you do a quick look to the left or right to check your blind spots. One the biggest mistakes drivers make is not head checking. I don’t care how many mirror checks you do, you can still have a car right alongside you and not even know it unless you check the blind spot. What are you looking for? You’re looking for (a) the volume of traffic in the lane into which you intend to move, (b) the speed of that traffic, (c) a gap into which you can move and (d) any vehicles in your blind spot.
  3. Accelerate to traffic speed. Never slow down or stop on an on-ramp. If you have an emergency such as a blow-out or sudden engine failure on the ramp move quickly to the right as far as possible and out of the way of others behind you who are also accelerating. When safe move into the nearest available traffic lane, adjust your speed to the speed of other traffic in that lane, cancel your turn signal and establish a safe following distance.

The recommended safe following distance at typical highway speeds is from four to five seconds. If you don’t know how to calculate safe following distances, check in next time. I will be discussing following distances in our next blog.

This is not about how to drive. It’s about staying alive!

About Robert Sears

Robert Sears is a professional driving instructor who once owned a company that trained more than 70,000 people to drive. Today he is an author working on several non-fiction books and writing traffic safety articles for consumer and special interest publications. He is a 30-year motorhome owner who has logged several hundred thousand miles of RV driving experience.

One comment

  1. This article is the best I’ve ever read on this subject!

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