Typically in the United States if you neither pay the fine by the deadline displayed on your ticket, nor appear in court on the date specified, the traditional judicial response is to issue a bench warrant for your arrest for failure to appear (FTA) or failure to pay (FTP).

For example according to the Philadelphia traffic court site, if the Defendant fails to respond to the Citation within ten (10) days, an administrative fee of $25.00 will be imposed.

If the Defendant fails to appear for trial, the trial may be held in the Defendant’s absence. If the Defendant has been charged with a summary offense under the Vehicle Code, failure to respond within the time specified above will result in the suspension of the Defendant’s driver’s license and the issuance of a warrant for Defendant’s arrest.

So at least an extra fee of $25 will be applied to your speeding ticket, but it will likely go up the longer the citation goes unpaid, especially if it goes to collections and they have to pay a collection firm to try and track you down.

It would also appear that if you do drive in PA again that your name would be listed as one that had a FTA and thus a warrant would be out for your arrest. We have read that in Pennsylvania your vehicle may be impounded if you have unpaid traffic fines in excess of $250 however you should check with the country court where you received your ticket and/or a lawyer to find out more about what your penalties may be if you ignore the PA traffic ticket but continue to drive here or come back to visit.

It may be possible that you could be written up for more than a failure to appear if you drove again in Pennsylvania since it appears they would suspend your driving privileges in the state until your citation was properly taken care of. If you were from another state in the United States then your licensing state would likely also suspend your driver's license until the ticket was taken care of. Since you are from Canada you would need to check with PennDOT and your own province's Ministry of Transportation, or like government agency, to find out if they have any reciprocal agreements that could affect your driving privileges at home in Canada.