You may have heard the term 18-wheeler and wonder where the name comes from. It turns out those 18 wheels have an important purpose. Here's what we know.

The ambulance stopped at a red light, but as it proceeded, crashed with a semi-truck traveling through the intersection. The ambulance spun 180 degrees and struck a Rocky Mountain Power truck.

Just before 2:30 p.m., the Dorchester County Sheriff's Office reported a stretch of I-95 outside of Reevesville was shut down due to power lines being taken down by a semi-truck.

The spikes on semi-truck wheels are covers that protect lug nuts from road debris. They may also encourage drivers to give trucks extra room on the road.