Semi tractor-trailers are different than passenger vehicles: They are up to 75 feet long and weigh up to 80,000 lbs. when fully loaded, compared to passenger vehicles that are 12 to 20 feet long and typically weigh 2,000 to 4,000 lbs. Heavy trucks require, when fully loaded, about 1,700 feet and 40 seconds to accelerate to 60 mph, when high-performance passenger vehicles require only 220 feet and five seconds to do the same. When it comes to braking on dry asphalt, a semi needs at least 250 feet to stop from 60 mph where high-performance passenger vehicles only need 115 feet to stop.