Tricycles are motorcycles attached to covered sidecars. In Thailand, they have "tuktuks"; in this country, we just call them tricycles. There are bike (pedal) powered versions, and the faster motorcycle driven ones. Around Metro Manila, they cover the small streets, alleyways, and villages where jeepneys and buses aren't allowed to traverse. They can be a pain in the butt when you're driving behind one, and on a road trip, it's annoying to have one cut in front of you on the highway.
There isn't one standard size/form for tricycles. And my balikbayan guest noticed the differences right away. Perhaps it was a pity that we had the top end of tricycles in Dumaguete, wide bodied, able to fit 3 people or more given tiny Pinoy bodies. They were pretty comfy and had sufficient leg room.
The ones up north however (and I remember correctly, it's just the same in MM), the trikes are smaller, cramped, and seem to have metal bars that bang against your head if you don't crouch down.
What does it signify? Are Visayan people bigger, hence the larger, limo style trikes? The folks up in Abra told us that they used to have bigger trikes, then realized the smaller, more aerodynamic ones go faster. Not that they need a reason to drive like the devil.
I think someone should design cool caps for the trike drivers, think Peter O'Toole in Lawrence of Arabia, hoodie and glasses flapping in the wind!