As you are driving there are many other vehicles around you. Whether these are other commercial vehicles or if they are passenger vehicles - certain items are a courtesy to all of those with whom you are sharing the road.
RULE #1 - Sharing the road. This includes all vehicles, motorcycles, bicyclists, stranded vehicles and emergency vehicles. Make sure you are giving everyone enough of a cushion and moving over a lane (if you are able).
RULE #2 - Maintain a proper following distance. You should allow for one second per every 10mph (if you are going 60mph, you should have a six second following distance). Do not tailgate! Even in heavy traffic, make sure you have a cushion in front of you and if need be, slow down to ease out of the congested traffic. If you want to check your following distance, find a stationary object (i.e. a telephone pole) and count the seconds until you are at the spot where the vehicle passed.
RULE #3 - Observe the proper speed for conditions. Make sure you are driving at an appropriate speed for the weather/traffic/construction. This comes into play more so during the winter - please make sure that you are not speeding and slowing down so that you arrive safely to your destination.
RULE #4 - Always signal a lane change in advance. This ensures that everyone around you knows your intentions. It will also help those around you to get out of any blind spots or back off to allow you to make your maneuver.
RULE #5 - Know your blind spots and manage the space around your trailer. Make sure you are checking your mirrors often and know where the traffic is located. When checking blind spots - using the 'lean and look' method to ensure the area by the tractor is clear when you are changing lanes or turning.
RULE #6 - Slow down when entering a ramp, curve or turn. The posted speed limit signs are meant for passenger cars, not commercial motor vehicles, so please make sure you are slowed down when making the turn to avoid a rollover or another issue.
These are just a few of the rules of the road. Please make sure you are following all traffic laws and regulations while driving. And, of course - DRIVE SAFELY!