Chariots were very light, they enabled the driver to go as fast as possible. It would’ve probably be like driving a basket on wheels.
A charioteer or horse who had won over a thousand races was called a miliarius.
Back in those times if a horse was sick or injured, they would become useless to the chariot driver, this was sad for the horses as the driver would have to kill them.
Chariot racers didn't have lanes to ride in, in fact the whole purpose of chariot racing was knocking everyone over.