The main means of getting around Hanoi (and possibly all of Vietnam) is the motorcycle. Big displacement machines are pretty much non-existent, but that doesn't stop people from putting 250 kg (550 pounds) on their 110cc scooters on a regular basis. Two people on a scooter is very common. I've seen five, and four as above happens pretty often. It's slightly less dangerous (but only slightly) than it looks, as traffic in Hanoi rarely gets above 40 km/h (25 mph). Some scooters are fitted with massive carrying baskets behind the rider. I've seen a 31" TV. A guy with ten cases of beer behind him and another six in front is something I saw several times approaching Tet. But you don't have to come to Hanoi, or even Vietnam to see this kind of thing: anywhere in southeast Asia will do.