DUBLIN, Ireland - The posted speed limits in Ireland are about to change dramatically, but few people are sure whether to hit the gas or the brake.

A nationwide switch Thursday from miles to kilometers has been designed to bring consistency to the country's roads, where two systems have been used for decades: speed limit signs are in miles, most destination signs in kilometers.

But the streamlining is introducing new confusion to a country where the roads can be maddening because of lax law enforcement.

One typically confusing example: Most highways and country roads are having their speed limits lowered from 60 mph to 50 mph. But the new signs will be in kilometers, so the speed limit will actually read 80 kph.

"They can list these speeds in watts or grams or, whaddya call 'em, megabytes - I still won't get a ticket," said Pat Cullinane, a Dublin taxi driver who, like just about all drivers in Ireland, has a car with a speedometer principally in miles.

Some drivers have added colored markings on their speedometers to highlight the new limits. Most people plan, as usual, just to go with the flow of traffic or, when it's quiet, as fast as the road will allow.

Road safety campaigners hope the speed limit reduction on the country's most dangerous and poorly policed roads will mean fewer deaths.

Ireland - an anomaly within the 25-member European Union, where road deaths have been falling - suffered a strong surge last year in traffic fatalities: 380 dead, or about 10 per 100,000 people; 336 died in 2003.

That rate is nowhere near as bad as most eastern European countries, but it's also far from Ireland's long-term goal of matching the statistically safest countries: Britain, the Netherlands and Sweden, where six of every 100,000 typically die in crashes each year.

"We're trying to create a greater degree of common sense," said Brian Farrell, spokesman for the National Safety Council, which distributed leaflets to 1.6 million homes this month that spell out the speed limits changes.

Farrell said crews this week were taking down about 35,000 existing speed signs - including a ubiquitous white sign with a black stripe that displayed no number but represented a "general speed limit" of 60 mph (that's 97 kph) - and replacing them with nearly 60,000 new signs with limits written explicitly.

On many roads, he said, drivers "might become conscious for the first time of what the limit actually is."

The big problem facing any new road law in Ireland is the widespread belief that it simply won't be enforced. That's understandable in a country where the police established a traffic enforcement division only two months ago and where drivers' offense records still aren't fully computerized.

The government says about 250,000 people - or 17 percent of drivers - have either failed to pass a driving test or are still waiting to take one. Yet under Ireland's unusual licensing laws, people who fail a test are issued with a "provisional" license anyway.

It's little wonder then that encountering jaw-droppingly bad drivers in Ireland is an everyday occurrence.

"Ireland remains Europe's Wild West in terms of enforcement. Nowhere in the western world is it safer to speed or drink-drive," said David Maher, director of a bicycling rights pressure group called the Irish Cycling Campaign.

A major push to instill fear of enforcement launched in 2003 worked for a few months. The death rate dropped as drivers slowed down, fearing for the first time that they could lose their licenses if caught speeding too often.

But word quickly spread that the risk of being caught was low and, worse, drivers who were ticketed but failed to pay their fines mostly didn't end up in court.

Kevin Myers, an Irish Times columnist who frequently writes satirical columns on the relative lawlessness of the roads, recently mocked the police's Christmastime anti-drunk driving campaign.

He noted that the police's own figures - 1,974 people breathalyzed during a five-week crackdown - averaged to just two people tested per day in each of Ireland's 26 counties.

"With visible policing, people tend to drive more slowly and not drink and drive. But happily, across the (Irish) Republic over the crucial five-week holiday period, we managed to abolish policing - visible and invisible - altogether," he wrote.