Nearly 900 drivers have reported aggressive behaviour by other motorists under a pilot scheme operated in the south-east by the Garda.
Since December last, drivers in the region who witness reckless or potentially dangerous driving by others are being encouraged to phone a low-cost number, 1890 205 805, to report the incident.
A decision on whether to extend the scheme, known as Traffic Watch, to the rest of the State is to be taken shortly. Insp Michael Melia, the Garda traffic inspector for the south-east, said the scheme had received an excellent response from the public, with over 850 complaints registered to date.
Dangerous overtaking was among the most common offences observed, but a variety of transgressions ranging from tailgating to non-wearing of seatbelts had also been reported.
Obtaining convictions was not the main objective of the scheme, but a number of prosecutions for drunk-driving had been initiated as a result of calls made to the Traffic Watch number, he said.
"The advantage in a drunk-driving case is we don't need a witness. If we get the call and it is acted upon immediately we can obtain the evidence ourselves."
While the scheme operates in Wexford, Tipperary, Kilkenny, Waterford and Wicklow, calls received from outside the region had also been acted upon, he said. A number of drivers had observed signs with the Traffic Watch number, erected in the south-east by the National Roads Authority, and made complaints from other parts of the State.
Drivers phoning in are first asked if they are using a mobile phone and, if this is the case, are instructed to pull over.
They are asked for the registration of the vehicle they are reporting, its location at the time of the incident, the direction in which it was travelling and a brief synopsis of what happened.
Calls are treated in confidence and, while complainants may be asked if they are prepared to make a statement or attend a court hearing, in most cases gardaí will simply call to the alleged offender and issue a caution or advice.
Although it is too early for a link to be drawn between the scheme and the number of road fatalities in the region, the early signs are encouraging. Up to Monday of this week 14 people were killed on roads in the south-east, compared to 20 in the same period last year.