Irish speed limits will go metric next September, changing from miles per hour to kilometres per hour, the Minister for Transport, Mr Brennan, said yesterday.
"It's got to be done on a single day, like changing the currency," he said.
However, he would not be drawn on whether the Garda would be asked to "go easy" on speeding offences after the changeover.
Mr Brennan said limits were also being reviewed. For example, the current 60 m.p.h. (96.5 k.p.h.) on narrow country roads is being reduced to 50 m.p.h., which will translate to 80 k.p.h.
Asked whether the existing 30 m.p.h. limit in urban areas would be redefined simply as 30 k.p.h. (18.6 m.p.h.), he said the lower limit would be imposed only in areas where traffic calming measures were being applied.
The National Roads Authority is planning to "retro-fit" observation platforms and lay-bys on national routes for the Garda to detect speeding. But the Minister said he was sure the Garda would "help motorists through the process".
The changeover is to be heralded by a public information campaign and by a switch to priority for k.p.h. on speedometers of new cars. Talks with the motor trade on what to do with old cars are continuing.