Maryland traffic violations are either payable (minor) or must appear (major) offenses. Payable traffic violation include speeding tickets and other violations - where you could plead guilty and pay a fine. This guilty plea shows up on your driving record and may affect your insurance. Another option is contesting the charges in court. Must appear major offenses are for drivers license suspensions and DWIs, which might lead to jail time.
A reliable lawyer can help prepare evidence and knows proper police procedures and applicable traffic violations law.