Ping is not something that you can fix - unless you yourself own the cable company. Ping, which is the time it takes for a signal to go from your computer to its destination, is a function of distance, and how many hops are required to get to the destination. Everytime it goes through a router, server, gateway, or other networking system you get a small ammount added to your ping. You also get a cirtain ammount of delay per so many miled of distance traveled as propegation delay in the wires or optical cable.
The only thing one could try to do - ever - is try to fool your service providers CMTS (which determins which path to take to the destination) - often times if the company has alot of traffic through one line they will re route you through a different line (even if it is longer) in hopes that the less traffic will make up for the difference. Even then, as a user, i dont much think that you can change what the all knowing CMTS determins to be your fate.