Unless you're involved in law enforcement or have been in the criminal justice system before, you are probably not aware of what an expungement is. Expungement is the removal or isolation (sealing) of all records on file with any court, jail, police agency, etc. for a specific person or event. Anyone who has been arrested or convicted of a crime or infraction can likely request their record be expunged.
The reasons for expungement are varied, but it is not considered a right by the government. It's a privilege granted when certain conditions are met. These conditions vary by location, usually on a state level, but in general if it was a first-time offense for the petitioner and the person has been in good standing otherwise or if the criminal record will somehow negatively affect the person, an expungement is likely available.
Traffic tickets are often easily expunged – much more so than are criminal records. In most states, a person can take a traffic class or defensive driving course and remove their ticket record that way. More serious offenses will require a formal expungement proceeding, which can take months.
Once you have an expungement, you're able to legally answer “no” when asked if you've ever been convicted of a crime, had a speeding ticket, etc. Applying for expungement is very much worth it as the time and effort required to get one can mean better jobs and lower insurance costs later.