Bigger the Truck, Bigger the Damage

Simply because of the physics involved, wrecks with larger vehicles can be devastating.

If you're in a situation where you're close to another vehicle and it's much larger than the vehicle you're in, keep the following information in mind; it just might keep you from getting into a wreck.

Large cargo trucks and semi-trucks will most-likely be driven by somebody with a commercial driver's license. These drivers, in order to have these credentials, have special training and are generally better drivers than the average person. There's a reason why this is important.
The kind of vehicles that you can rent to move your furniture from house to house or for other purposes are almost as large as some commercial vehicles. Rental vans and trucks can be rented by anybody, and unfortunately, some of the people who you'll see driving these vehicles are really not very good at it.
Most of the time, it pays to be very suspicious of any of these trucks you see on the road. They're much more-likely to cause a truck accident than a professional driver.

Make sure they can see you.

Semis have huge mirror mounts on them that allow the driver to see more of what's around the vehicle. The limitation is that the driver can't see you if you can't see their mirrors. If you end up very close behind a semi and you can't see their mirrors, be aware of the fact that the driver may have no idea that you're there.
Another thing to keep in mind about large vehicles is that they create a strong draft. When you come upon a large truck on the freeway, it's likely going to blow you around a bit. Make certain that you're ready for this so that you don't end up losing control of your vehicle.
Some trucking companies are not very ethical in their business practices. One of the things they'll do is work their driver's way too hard (and beyond their allotted hours of service). When they do this, the drivers may become exhausted behind the wheel and may be serious threats to everybody around them.
If you see a driver who seems like they're having a hard time staying awake (or if their rig is having trouble staying in one lane), be sure to keep clear of them.