I worked for a very safety-conscious company. On-the-job automobile accidents invariably were our worst safety statistic even though we handled and produced many hazardous compounds. We started being required to have automobile safety training annually.
One of the things stressed frequently was to be aware where the blind spots for 18-wheelers are and to not linger in them on the highway. Speed up or slow down to move up or back, but don't stay in them if you are matched in speed. They exist on both left and right side of the rigs. Look ahead on the road for traffic situations that may cause the truck driver to have to make a sudden move to avoid potential collisions.
I agree with what some others have said. I observe many more dangerous drivers in cars, especially tailgating, speeding and veering through heavy traffic on congested freeways like they are in a road race.
Most truck drivers are very competent, courteous and safety conscious. I do observe tailgating and unsafe high speeds with a few of them. I think that small minority is what sticks out in many people's memory.