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Maintaining enough space around your car is essential for proper space management. This chapter emphasizes the need of controlling your car's speed to adapt to the constantly changing road conditions.


Your Cushion of Space


When driving a tractor-trailer, you must control your space cushion. This entails accounting for the area in front of, behind, to the sides, above, and under your vehicle. You need to have adequate room to react when traffic conditions change, including when a car unexpectedly stops or veers into your lane of travel without notice.


Space ahead — The area in front of your car is the most crucial and is also one of the simplest to keep an eye on and modify as necessary.


The amount of space ahead of your vehicle that you should allow for depends on the speed of your vehicle and road conditions. One rule of thumb to follow (in good driving conditions)

is to allow at least one second for each 10 feet of vehicle length at speeds below 40 mph. At greater speeds, add an additional second. In poor driving conditions (rain, ice, snow, fog, etc.), allow for a greater stopping distance.


Wait until the car in front passes a distinct landmark to assess your available space (pavement marking, road sign, etc.). then keep track of the time till you arrive at the same location. If you are going above 40 mph, add one more second to your count and compare it to the guideline of one second for every 10 feet of length. The "Fixed Object Count-Off Method" may be used to describe this.


For instance, you are following too closely if you are driving a 60-foot vehicle at 55 mph (in excellent weather conditions) and you only timed three seconds. There should be at least seven seconds between you and them.


You'll be able to decide how far back to follow with ease after some practice and road experience.


Space behind — Certain things may be done to prevent cars from following too closely. Back up far. Stay to the right and slow down to let the tailgater pass.


If you discover that you are being tailgated, you may take the following actions to aid in avoiding an accident.


  • Avoid quick changes — Steer clear of abrupt changes in direction. If you must slow down or turn, indicate before you do so.


  • Don’t speed up — Being tailgated at a slow pace is safer than doing so at a rapid speed.



  • Increase your following distance — Widen the space between you and the vehicle in front of you to prevent unexpected changes in speed or direction. Additionally, this makes it simpler for the tailgater to avoid you.


  • Avoid tricks — Steer clear of trickery; don't flash your brake lights or switch on your taillights.


Space to the sides — Commercial trucks often occupy the majority of a lane, so leave some room to the sides. To make sure there is enough room between your car and other road users, there are a few things you should strive to avoid.


  • Don’t hug the center line — it becomes quite simple to drift into oncoming traffic.

  • Avoid hugging the right side of the road — Steer clear of hugging the right side of the road; a soft shoulder might interfere with steering.

  • Avoid traveling alongside other vehicles — Avoid following too closely behind other cars. A motorist might swerve into your car or trap it in a situation where it can't change lanes. Additionally, avoid following other vehicles when there are heavy gusts, particularly crosswinds. Light or empty vehicles are more often affected by the issue.


Space above — Bridges, overpasses, trees, and wires need clearance. Never assume bridge and overpass heights. Repaving or compacting snow may lower reported heights.

A vehicle's height may be altered by the weight of its load. A vehicle that is not loaded is higher than one that is.


Be mindful of a road's grading. A high vehicle may tilt due to road gradient, which may pose a clearance issue.

Take another path if you are unsure if there is sufficient overhead room to continue.


Space below — Space under It's incredibly simple to overlook the area beneath your car. When the car is fully loaded, that space may be extremely little.


It might be difficult to cross driveways, railroad lines, gravel roads, and open spaces. In these situations, slow and steady wins the race. This is another justification for constantly turning the landing gear up.


Turning Space


Making turns properly requires following certain steps. Commercial motor vehicles incur the danger of colliding with other vehicles or objects during turns due to broad turning and off-tracking.


Right turns — Take your time while making a right turn. This offers you and other people time to stay out of danger. Additionally, look forward to seeing any prospective issues.


Turn wide as you make the turn if you can't make the right turn without swerving into another lane. Keep your car's back end near the curb. Although you may park your car in a way that makes it difficult for cars to pass you on the right, never presume that you have entirely blocked traffic. Keep an eye on the right side of the car since you never know when a smaller car could attempt to pass you on the right.

As you begin the turn, avoid making a broad left turn. A vehicle in pursuit may attempt to pass you on the right after assuming you are making a left turn.


Be on the lookout for incoming cars if you have to cross into the oncoming lane to make a turn. Never go backward to provide a way for them to pass or halt. You could run into someone while driving.


Left turns — Before beginning a turn to the left, check sure the car has gotten to the middle of the intersection. If you start it too soon, the trailer will go a lesser distance. Everything in the way will be crushed (light poles, traffic signs, other vehicles).


Always choose the turning lane that is furthest to the right when there are two available. Avoid beginning in the inner lane since you may need to swing to the right to accomplish the turn.


Space When Crossing and Entering Traffic


You will need more room to enter traffic than you would in your car because of the moderate acceleration and the length of your vehicle. Remember that acceleration changes depending on the load. If your car is highly loaded, give yourself additional space.


Make sure you can cross the whole width of the road before oncoming vehicles before you begin. A junction may be cleared in 7 to 15 seconds. It can take longer if you skip a gear or cross a busy junction.




The significance of controlling the whole area surrounding your car and how to create a safety cushion has been discussed in this chapter. Speed and space management work well together to provide safe vehicle operation.

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