Prince Edward Island motorists with multiple drunk-driving convictions could soon have to get coded licence plates telling police they are repeat offenders, if they want to keep driving without needing mini breathalyzers to start their vehicles.

The Prince Edward Island government is introducing new legislation to curb repeat drunk driving. (CBC)

The Island is the first province in the country to introduce such legislation, according to P.E.I. transportation officials. The plates are part of a package of changes to the Highway Traffic Act aimed at curbing repeat impaired driving. Licence plates for drunk drivers are used in some American states, including Minnesota and Ohio.

While impaired driving convictions are declining on P.E.I., the proportion of repeat offenders is growing, according to numbers provided by the province.

The legislation was introduced Friday by Transportation Minister Robert Vessey and has the support of the Charlottetown Police Service and other police forces on P.E.I.

"This legislation will give us another tool in our toolkit to help us keep these chronic offenders off our roadways and increase safety for everyone," Charlottetown police Chief Paul Smith said in a statement.

Transportation Minister Robert Vessey has introduced changes to the Highway Traffic Act aimed at curbing repeat drunk driving. (CBC)

The special licence plates will only apply to drivers serving a third sentence for being impaired behind a wheel.

Those drivers face a mandatory 10-year ignition interlock sentence. The ignition interlock devices prevent a vehicle from starting until the driver provides a clean blood-alcohol breath sample.

If drivers successfully complete half the sentence, they can apply to get out of the ignition interlock program and get a special licence plate and an administrative probation.

The licence plate will have a number or a letter placed in a specific spot in the identification sequence that will allow law enforcement to identify the person as a repeat offender.

"It will not be a scarlet letter that will be identifiable to anyone, but will be a plate that looks like any other plate on the road … with a special code recognizable only to the registrar of motor vehicles and to police," Vessey said, according to his prepared remarks.

Other changes in the Highway Traffic Act include: