The M18 is the Galway-Limerick motorway and the N17 the single carriageway Galway-Sligo road. The N17 only has stats available for the Galway-Tuam segment, to be covered in future by the new M17 which will follow a different, more directly southward route. Traffic levels along this part of the Atlantic Corridor are meaty. It's no surprise that motorway was specified for the lot, and mostly in place. Although post-2007 figures are experiencing downward pressure due to the recession, even Gort was showing 10,000+ at its height.
Due to the delays in getting the M17/M18 Gort-Athenry-Tuam motorway underway, which will finally kick off in the first half of 2013, there is concern over chronic traffic congestion in Claregalway, which is due to get its own minor bypass. This is hardly surprising since it is counting nearly 25,000 vehicles per day, which has only fallen slightly in recent years.
Traffic further south between Shannon and Limerick is very high, ranging from the high 20s to the mid-30s. The Limerick Tunnel bucks the trend, though, presumably due to the toll one has to pay.
In 2010, a large number of new data points were added.