Ardagh is where the eponymous eighth century chalice, the country's most famous treasure, was discovered in 1868. The parish has the largest ring fort in Ireland. Ardagh was once a monastic settlement owned by the Bishop of Limerick. In the Great Famine times, Ardagh was a place of much misery due to widespread evictions in the district.

Much later, Ardagh creamery butter took several prizes in London as well as in Dublin. So you're driving along and pondering all about Ardagh, its many achievements and its difficulties down the years, when suddenly you're looking at something which must surely be a mirage. But no, there it is, a full set of traffic lights, even with lights suspended on cantilevered supports above the centre of the road.

These are not flashing pedestrian lights, such as are to be seen outside every school in the county. Nor are they request lights for crossing like the set at Abbeyfeale church. No, these are fully programmed green, amber and red lights positioned at each corner of Top Cross, as well as the extra lights suspended above, controlling the passage of traffic into the junction from all four approaches.

With the exception of Raheen / Dooradoyle, the only set of traffic lights in the entire county had been the ones at Newcastle West's busiest junction on the main Limerick to Kerry road. Ardagh, for all its heritage, doesn't have a national primary road passing through it, yet its traffic lights are far more dramatic than the ones in other places, not least because their presence is so unexpected at first visit.

In fact, of course, Ardagh does deserve its traffic lights because the development of Foynes port in recent years and the closure of Foynes' rail link has put many more heavy goods vehicles on the road to Newcastle West and the south. The other road at Ardagh, that from Rathkeale (Reens) to Athea and on to Listowel, is less busy, but the junction can't be staggered or "roundabouted" owing to the proximity of existing buildings. Ardagh itself is expanding as a dormitory community, with its residents commuting daily and with the safety of children to be considered. There have been numerous accidents at the cross in question.

A senior council engineer told me once that we have a love affair with roundabouts—big one, small ones, all kind of ones. The problem, he said, is that only a fraction of drivers know how to use them. I still recall with horror the sight of an elderly gentleman who pulled up on the Parkway roundabout and actually reversed because he had seemingly missed his exit. It wasn't all that busy on the day and other traffic managed to avoid him as he manoeuvred his way backwards.

Roundabouts can ease junctions where a smaller road or roads meet a busy road and where there aren't many pedestrians. There are a few in the county which facilitate flow and I can well recall the almost impossibility of emerging from Raheen Industrial Estate in the evening before the roundabout went in and long before the dual carriageway to Patrickswell was built a mile to the south. Indeed, emerging from Station Road in Adare was equally a problem before the button roundabout was put in.

Passers through Adare will also have noticed the new but not yet commissioned traffic lights on the bend at the Killarney Road. These will be valuable when the new 100 million hospital has been built and further housing will have been be constructed. Of course, it might well have been the case that the lights, a simple set, were designed on the assumption that Adare would have been bypassed sometime soon and that the only passing traffic would have been that to Ballingarry, Kilmeedy and Dromcollogher. I fear, however, that monetary constraints will delay Adare's relief road once more.

Many years ago, a city councillor proposed traffic lights, with pedestrian phases, on every junction on O'Connell Street, William Street, Patrick Street, Henry Street and Catherine Street, and that was at a time when all traffic from Dublin to Kerry and from Galway to Cork passed through the centre of Limerick. The city council number crunchers as much as said that it would take the entire municipal budget to pay off the price of them over whatever number of years and to maintain them on a day to day basis.

Today's planners have it right—move the through traffic away from the city altogether and let the place breathe.

In the meantime, go along to see Ardagh's fine new lights, with associated new paths, sensitive landscaping and signage. The famous chalice might date from the year 700-and-something, but the new development is pure 2008.