It seems that a highway is a secure place but in fact, it is not always like that. Be careful on corners (e.g. with speed limit signs). If your truck has one rear axis (4x2) you may lose control over your vehicle and smash the barriers. Upgraded chassis (6x2, 6x4) makes your truck more stable and safe.
Also pay attention when driving through narrow city streets. Remember it is not so easy to turn with a long trailer. Before the turn go straight into the middle of the intersection and then start turning.
Therefore, you will avoid a collision with other vehicle standing on the next lane. The trailer must find its lane at once when turning, it cannot take any other one. It is crucial when driving through narrow one-lane streets.