Ryan Michael Rooke was ordered to have an alcohol interlock device fitted to his vehicle after first completing a disqualification period for the offence.

The stricter requirements for NSW drivers convicted of high range, repeat or other serious drink driving offences started on February 1.

Rooke, 19, pleaded guilty in Dubbo Local Court to having a blood alcohol reading of 0.156 - three times the legal limit.

This week magistrate Claire Girotto disqualified his licence for six months and made the interlock order for two years after the disqualification period expired.

Rooke was stopped for a mobile random breath test about 11.30pm on March 19 after police observed him travelling without headlights on from Macquarie Street to the McDonalds car park.

The defence submitted Rooke was a full-time heavy vehicle diesel mechanic who worked long hours.

He was awarded apprentice of the year at the 2014 Dubbo Chamber of Commerce's Rhino Awards for Business Excellence, the court heard.

Rooke had received a substantial warning from his employer for the offence, because as a diesel mechanic he was required to travel, his solicitor said.

It had taken the offence for her client to concede his drinking was "out of control", the solicitor said.

He had a new level of maturity since he was detected, and understood his licence was not a right, the solicitor said.

The defence suggested the minimum interlock order - one year - but a two-year order was put in place.

The cost of the interlock order imposed will fall to Rooke to pay.

The new legislation requires high-range drink-drivers - those with a reading of 0.15 and above - and reoffenders to pay an estimated more than $2000 for a minimum 12-month interlock system.

The mandatory interlock program was developed by the NSW government, the NSW Road Safety Advisory Council and NRMA Motoring and Services.