If you drive on Interstate 65, you're almost guaranteed to see a semi-truck.
In fact, in Kentucky, commercial trucks make up more than 50-percent of all interstate traffic.
These trucks can carry different things, including some things that could be harmful to you.
More than 6,000 thousand of these trucks creep across the scale at the Simpson County Weight Station everyday.
Before they can continue down one of the busiest interstates in the country, they must pass a mandatory inspection.
"As a commercial vehicle comes through, he is required to stop at the facility's opening," explained Officer John Kearns, with the Kentucky Vehicle Enforcement.
Kentucky Vehicle Enforcement officials use an automated system to check these 18-wheelers for dangerous content.
"Anything from hazardous materials to nuclear ordinances going to Richmond," Officer Kearns added.
Homeland Security has provided the weigh station with radiological detectors which spot radiation leaking from trucks.
The station also has an infrared iris system that uses heat signals to monitor the semi's.
Officer Kearns said these tools have helped them catch contraband being brought into the state.
He added that having this equipment is extremely important with terrorist attacks always possible.
"The facility's been upgraded as a result of Homeland Security by implementing some of this new equipment--the new radiological detectors and the iris systems," Kearns continued.
The responsibility of protection doesn't only fall on the shoulders of KVE.
Kearns said the truck drivers also police the roads for any suspicious activity.
"These guys that run the same route over and over again, see and know the area that they travel in. When something's out of place, they have a tendency to pick out what's out of place and notify us," Kearns assured.
The Simpson County Weigh Station, just near the Tennessee state line, is the only commercial vehicle specialist in the state.
Kearns said KVE also has officers posted at other points of entry from Tennessee to Kentucky to monitor commercial trucks.