We met a guy from Ireland who gave us a "rule of thumb" about driving distances. He said that you should allow_____minutes per kilometer as the driving is slower than you think. We didn't write it down and now can't remember what he said.

Anyone???

Depends on where and how you drive. A lot of folks will tell you 35 MPH. It may or may notbe accurate, but in Ireland you are better to err on the side of caution because you never know what you might come across. Traffic, sheep, farm equipment, construction, sheep, wrong turns, right turns, sheep, and unplanned stops at someplace that tickles your fancy all lead to you not getting there as fast as if you hopped on I-94 and headed down to Chicago.

Depends.

Most people who tell you that you cannot average more than 30mph/50kph spent their time on scenic byways or let their GPS take them on some one-lane local roads.

But nowadays you will find many new motorways in Ireland that allow for much higher averages (if you want or need it).
For example, Dublin-Cork is all motorway now - but you can still opt for the slower national roads or take the longer and more time-consuming coastal route.

My subjective averages would be:
motorways (M roads): 100 kph average
single-digit national roads (N roads): 80 kph av.
double-digit N roads: depends, 50-70 kph
regional roads (R roads): 40-60 kph
local roads (L or not numbered): depends on average number of sheep or dogs per km

This guy had an average minute per kilometer that he said worked. Like if you were driving 100 kilometers you could reason out x amount of minutes.

He was a tour guide and after driving the country for many years had figured out a reasonable formula. Taking into consideration the fast and slow roads and averaging it out.

The day to day touring is just that, but we have 2 long drives to consider.# 1, from Westport to Kilrush to get the ferry in the morning on to Dingle. # 2, from Kenmare to Shannon with a stop in Adare. Should we just plod on, or do we have a little time to tour?

Cowboy1968---I apprecite your detailed directions from another thread for the new motorway under the Shannon River from Adare to Shannon airport. We plan on using it.

you simply can't do a formula x minutes per mile/kilometer. On small roads in scenic areas 30-35 mph, on motorways up to about 60mph average. And both could be slower be faster depending on conditions.

Westport to Kilrush and on to the ferry terminal is approx 125 miles and would easily take 3.5 hours if things go really smoothly - and if not -- longer. (That is definitely one of the 35 mph routes)

The problem with statistics is that they are of not much use for singular events.

Your Mr Tourguide probably has a number of tours that he regularly offers every year. Obviously, he will know by now the average. But that is of no use for your two individual routings you need to calculate.

The 190kms from Westport to Kilrush (part of your route #1) could be anything from 1 1/2 hrs (if there were a motorway) to 3 hrs (given by Google maps, with no traffic problems calculated) to 4 hrs (if you run into traffic jams on N18 between Galway and Ennis due to the construction of the M18 motorway in that area).

So, the 3.5hrs that janisj mentioned would be the specific estimated minimum for exactly that routing.

Thanks for the responses.

I do believe that we are "overthinking" this driving thing.

Which means that we will just go with the flow and enjoy. After all we are on vacation.

TPAYT wrote: "we will just go with the flow and enjoy".

Now, there's an interesting idea. I wonder if many people might try it? Or might it interfere with planning?

Totally agree with not over-thinking (went in June and wished I had not spent so much time road-mapping in advance), particularly if you have GPS - you aren't going to get lost, and it is not so different from the US to adjust for city rush-hour traffic or high season for the major tourist venues.

Many of the roads are little more than country lanes (there is a dearth of interstates or even major highways) and there are a LOT of sheep. Even if you want to go faster, I would think 40 mph is on the high end.

There is no dearth of "interstates" (now). It's just that those motorways and major highways are there where the traffic is. They connect Cork, Limerick, Galway, and the North with Dublin. But not Dingle with the the Cliffs of Moher.
Most tourists drive along the South/Western coast where there is no real need for a 4-lane motorway. And probably no reasonable cost/benefit ratio to justify major upgrades.