As I am not licensed in your state, I cannot offer you specific legal advice as to Pennsylvania state law. However, if you do not fight this ticket, you may find that your insurance premiums may increase should your wife be convicted. If the cop issuing the ticket is not an actual eyewitness, what could he offer as testimony as to your wife traveling "without safety"? It is up to the state to prove all of the elements of the charge.
You may wish to consider hiring an attorney in your area who handles traffic court matters.
An attorney familiar with the policies and procedures of the court will know the likelihood of negotiating such a resolution given the circumstances of your case.
Check with a lawyer in your locale to discuss more of the details.
Good luck to you.
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