While specific instructions depend on the state that issued the ticket, generally,there is a process for what to do if you miss paying a traffic ticket.
In most cases, on the back of your ticket, there is a telephone number to call during specific hours to arrange to pay your ticket. Failure to pay a traffic ticket results in a bench warrant for your arrest. In some cases, depending on the particulars, such as number of tickets, points on your driving license and the severity of the offense, the issuee could also get jail time.
Most of these rules must be followed verbatim. You must call within a certain amount of time. If you do not, the bench warrant is issued. However, some county offices also allow you to pay your ticket by a certain date. To see if this is a viable option, contact the office where the ticket was issued.
If you've missed a payment, call the office immediately. A simple Internet search can provide the number if you no longer have your ticket. If you ignore it, usually the warrant is issued, rather than give you another chance to pay the money on your own schedule. There may not be another option. The office may allow you to pay a fine and continue payments. The only way to be sure is to contact the county office -- or go there in person -- and discuss your options.