The third annual “World’s Largest Truck Convoy” takes place this weekend to raise funds for Special Olympics. In every participating state, big rigs will gather at the start of a designated route, and drive to a destination a few miles away. Jeanette Steinfeldt with Special Olympics Iowa says this Saturday drivers will roll into West Des Moines. All are “big rigs,” over 10-thousand pounds gross vehicle weight like the semis you see driving down the road. Each one that enters will pay 100-dollars. The owners, trucking companies, and others are also invited to pledge money for Special Olympics. Off Interstate-35 she explains they’ll take Highway 5 to an exit known as the “southwest connector,” then drive a 20-mile route across Des Moines to the State Fairgrounds. People are welcome to come to the east 33rd street entrance to the fairgrounds, “to see the big rigs roll in.” Steinfeldt says the event usually raises about fifteen-thousand dollars for Special Olympics Iowa. Drivers who hear about it can register (tomorrow) the morning of the event from seven till 10.