"You can't really nail down one specific fault."
Mr Reid said both truck and car drivers could be confident around town, but may be less experienced on back roads.
He said the trucking industry is pretty focused on driver training to make sure the drivers are upskilled before they were "let loose".
Mr Reid first entered the national truck driving competition in 1988, and twice won the top title during the 1990s. He picked up his third title earlier this month.
He said there was a 20-year gap when there wasn't a national competition, but it was resurrected in 2015 and he has entered for the last three years.
Mr Reid competed alongside three of his staff, who had also won their categories at the Northland regional competition.
He said he was it was quite a humbling experience to win, but now he is retiring from the competition.
"I'll attend in a support role, to give the young guys pointers. If I could see or help or mentor some else through to win it, that would be a bigger feather in my cap."
The competition included a theory test, a search for preset faults in a vehicle and an obstacle course.
Simon's top three safety tips for motorists around trucks:
-Visibility. If you can't see their mirrors, they've got no idea you're there. Make sure the truck can see you.
-Stay out of the blind spot. Don't sit up under the left-hand side, next to the passenger's door, they can't see you.
-Patience. Don't take chances, if you have a second thought about whether you can get through before the truck gets there, don't do it. It could be catastrophic.
