Figure 3.1  2005 Model Commercial Driver’s License Manual Overloading can have bad effects on steering,  braking, and speed control. Overloaded trucks  have to go very slowly on upgrades. Worse, they  may gain too much speed on downgrades.  Stopping distance increases. Brakes can fail when  forced to work too hard.  During bad weather or in mountains, it may not be  safe to operate at legal maximum weights. Take  this into account before driving.  The height of the vehicle's center of gravity is very  important for safe handling. A high center of gravity  (cargo piled up high or heavy cargo on top) means  you are more likely to tip over. It is most dangerous  in curves, or if you have to swerve to avoid a  hazard. It is very important to distribute the cargo  so it is as low as possible. Put the heaviest parts of  the cargo under the lightest parts.  Poor weight balance can make vehicle handling  unsafe. Too much weight on the steering axle can  cause hard steering. It can damage the steering  axle and tires. Under-loaded front axles (caused by  shifting weight too far to the rear) can make the  steering axle weight too light to steer safely. Too  little weight on the driving axles can cause poor  traction. The drive wheels may spin easily. During  bad weather, the truck may not be able to keep  going. Weight that is loaded so there is a high  center of gravity causes greater chance of rollover.  On flat bed vehicles, there is also a greater chance  that the load will shift to the side or fall off. See  Figure 3.1.  On flatbed trailers or trailers without sides, cargo  must be secured to keep it from shifting or falling  off. In closed vans, tiedowns can also be important  to prevent cargo shifting that may affect the  handling of the vehicle. Tiedowns must be of the  proper type and proper strength. Federal  regulations require the aggregate working load limit  of any securement system used to secure an  article or group of articles against movement must  be at least one-half times the weight of the article  or group of articles. Proper tiedown equipment  must be used, including ropes, straps, chains, and  tensioning devices (winches, ratchets, clinching  components). Tiedowns must be attached to the  vehicle correctly (hooks, bolts, rails, rings). See  figure 3.2.  Blocking is used in the front, back, and/or sides of  a piece of cargo to keep it from sliding. Blocking is  shaped to fit snugly against cargo. It is secured to  the cargo deck to prevent cargo movement.  Bracing is also used to prevent movement of  cargo. Bracing goes from the upper part of the  cargo to the floor and/or walls of the cargo  compartment.  3.3 – Securing Cargo  3.3.1 – Blocking and Bracing  3.2.4 – Balance the Weight  3.3.2 – Cargo Tiedown  3.2.3 – Don't Be Top-heavy  Figure 3.2  Page 3-2 Section 3 – Transporting Cargo Safely 