THE number of tipsy drivers who voluntarily check their blood-alcohol levels has gone up since the start of the police's 'ring-fencing' of nightspots.

Major nightspot Zouk has seen a quadrupling in the use of its hand-held breathalysers, while St James Power Station has seen a 20 per cent jump.

The latter club said 750 of its patrons have used its devices each week since the move by the police to set up road blocks on random nights which seal off all escape routes out of entertainment districts.

Zouk, which has four Tiger Beer-sponsored breathalyser units, say 20 of its patrons use them each night, up from fewer than five three weeks ago.

The megaclub sits in the heart of the Outram-Havelock area, where simultaenous road-blocks by the Traffic Police went up in the early hours of Feb 17, catching 20 drink drivers who were leaving the clutch of clubs, bars and karaoke lounges there.

The step up in enforcement comes on the back of 4,009 drink drivers having been caught last year, a seven per cent increase from the previous year and a 10-year record high.

In the first nine months of last year, at least 11 people were killed and 193 injured in drink-driving related accidents.

Zouk has offered hand-held breath testers since last May, while St James has made them available since last November.

Asia Pacific Breweries, which distributes Tiger Beer, plans to put such breathalysers in four watering holes in the Dempsey party district as well.

Those who drive drunk can be fined $5,000 or jailed six months; repeat offenders can be fined up to $10,000 and face a mandatory jail term of up to a year.

Convicted offenders are also disqualified from driving for at least a year, even if they do not cause traffic accidents.