More heavy farm equipment will be out on the roads as spring planting season moves into full swing.
Farm equipment is not designed to travel at highway speeds and they also take up more room.
MoDOT says drivers should use extra caution when out on the roads.
"It's easy to get distracted while driving and obviously the farm equipment that hits the roads is sometimes slow moving, it's slow in accelerating, and slow in decelerating," said MoDOT engineer Michael Rinehart. "So, we just want people to be aware, have that heads up attitude while they're driving."
Farmers are only allowed to drive heavy machinery between sunrise and sunset and they must display a slow moving vehicle sign.