Sometimes I wonder which would be the slower vehicle — the paver that lays asphalt on roads, or the Zamboni ice resurfacer. While I’m pondering over it, here’s a Zamboni build to add to your city ice skating rink for all minifigure inhabitants to enjoy a smooth slidin’ surface to skate on, courtesy of de-marco.
And best yet, you can build it yourself with these video instructions.
Probably the crawler that carries NASA rockets to the launch pad. That or the school bus taking you home on the last day of school.
If we’re talking about factory-stock, road-legal vehicles, I believe the Mercedes-Benz Unimog takes the title. In “Super Crawler” gear has a top speed of about .06 miles per hour.