If you’ve ever driven on the freeway, you have likely witnessed a commercial truck driver carelessly change lanes. This can have catastrophic consequences as the average large truck weighs as much as 80,000 pounds. Causes of Unsafe Lane Changes Federal regulations mandate that all commercial truck drivers complete extensive training before they can take to the roadways with a commercial driver’s license. But despite the training requirements, some truck drivers still improperly change lanes. Causes may include: Failing to signal before changing lanes Failing to yield the right of way.