Standardbred
An Amish buggy.
There is no age limit to drive an Amish horse-drawn buggy. A child as young as 8 could drive one if they know how.
Usually by horse and buggy, but sometimes by foot.
Use of horse and buggy is the defining characteristic of the Amish in the United States. But it is not an exclusive trait as there are old order Mennonite groups that do use the horse and buggy as well. As for subgroups within the Amish, The Old Order Amish are the largest of the sects. Followed by The New Order Amish.
A horse and buggy is simply just a carriage pulled by horses. Nothing more or less.
The Amish
Usually 'buggy' means a carriage. Although a buggy is not a carriage, it is one of the vehicles that can be pulled by horses. There are also 'chariots', 'sleighs', 'carts', and 'wagons'.
The Amish will most likely drive a horse and buggies or even on bicycles. Only few Amish own cars.
I believe those are known as buggies because they reminded someone of a black-shelled beetle. Actually the Amish don't call them buggies it is their English thinking counterparts that call them buggies in reminiscent of the doctor's buggy of yesteryear. The Amish call their covered horse drawn vehicles carriages. Their smaller uncovered ones are simply known as wagons. The terminology may change within communities.
Wheelwrights are important in cultures that do not rely on gasoline engines to get around. The Amish are a group of people that rely on horse and buggy transportation and must have a wheelwright when a wheel breaks.
They don't have different roads, they use the main roads through America. Usually the roads get damaged due to the horse shoes and steel buggy wheels.
Old Order Amish define themselves as horse and buggy people. As a result they need pasture and land sufficent for keeping a horse. Some communities do not allow members to reside in town, viewing town life as inconsistant with Amish values. Some communities do allow memebers to live in town. In my town of Shipshewana, Indiana there are many Amish individuals residing in town. Many are unmarried girls who work in the local tourism industry and do not keep a horse, but rather ride a bicycle.