When I was 15 yrs old I was riding on a road I probably shouldnt have been riding on, when a semi dump truck passed me. He was going maybe 35-40mph, I was going maybe 20. Seemed like a long time for him to pass me. And I really had to fight being sucked into his slipstream. He was fighting staying in his lane as cars were coming the other direction. And little to no shoulder and terrible broken pavement. That was intense. Had to really lean and countersteer to keep from being sucked under the trailer/dump.