Just as drivers started to come to terms with the penalty points system introduced yesterday, the Minister for Transport raised the prospect of further confusion when he announced plans to change speed signs from miles to kilometres within 18 months.
Following his clashes with gardaí over the introduction of penalty points, Mr Brennan now proposes to embark on the logistical nightmare of revamping the State's speed signs.
Motorists will hope the initiative goes more smoothly than an attempt to introduce a new traffic-flow system to Dublin earlier this year when Mr Brennan ordered the removal of confusing road signs erected by the capital's traffic authorities.
Yesterday, in an interview with Mid West Radio, Mr Brennan announced that moves towards metric speed limits were already under way.
Acknowledging that it would cause "a degree of confusion", a spokesman for the Minister said: "There will be overtones of the public information campaign that preceded the euro. We're going to give this a good lead-in period. But logistically it is going to pose quite a few problems that have yet to be ironed out."
Motorists travelling from Northern Ireland face additional difficulties. Unlike the Republic,which has agreed to implement an EU directive standardising road signs, the UK is persisting with imperial measures.
Welcoming the announcement as long overdue, the motor industry called on the Minister to take the opportunity to review speed limits. In some areas limits were absurdly low, while in others they were dangerously high, an AA Roadwatch spokesman, Mr Conor Faughnan, said.
Metrification would cause some confusion but not enough to lead to driving accidents, he said, adding: "Some very old cars do not have metric speedometers, but this can be solved by a visit to the garage.
"And while it is true that the miles-per-hour read-out is the more prominent on many dashboards, there is no reason to believe that drivers won't become used to the new system in a short period."
Mr Brennan also plans to convert distance signs to kilometres, but only after he has revamped speed signs.
"At present, it's confusing to see a 10-mile road direction sign for Ballina in one spot and a mile down the road a different sign showing the same destination at 15km," he said.
The AA yesterday reported a significant decrease in driving offences on the first day of the penalty-points system. The association based its data in part on findings of the Garda traffic division for Meath-Louth, which was tasked to closely monitor the impact of the speeding clampdown.