Has the likelihood of a pedestrian fatality in Clonard increased?
Below are some guesstimates on the traffic speed increase through the village since the opening of the new M4 motorway. The fact that a pedestrian and truck involved in a traffic collision is nearly always fatal at most speeds has been ignored for the purposes of these figures.
From the National Safety Council we know that at 50kmph (30mph) the chance of a pedestrian surviving in a traffic accident is 50%
At 60kmph (40mph) it’s 10%
With the reduced number of cars through Clonard but at increased speed does this mean you are more likely to have a fatal pedestrian traffic accident?
Well let’s try some figures.
Assume that the traffic has reduced by half
Pre motorway at 50kmphh at the old levels you had a 50% chance of surviving a traffic accident so …
1 (traffic volume) divided by 0.5 (survivability) gives 2
Post motorway 0.5 of the traffic but only 1 in 10 chance of surviving so
0.5 (traffic volume) divided by 0.1 (survivability) gives 5
So you are 2.5 times (5 divided by two) more likely to die or put another way the chance of being involved in a fatal pedestrian traffic accident is increased by 250%
(NOTE: you can plug in other figures here for example say 300 vehicles per hour before the motorway opens gives …
Pre motorway 300 (vehicles per hour) / 0.5 = 600
post motorway 150 (vehicles per hour) / 0.1 = 1500
1500 / 600 = 2.5 times more likely)
Plug-in in some other traffic volumes
45% (traffic volume) 0.45 / 0.1 = 4.5 so 225% difference
40% (traffic volume) 0.40 / 0.1 = 4.0 so 200% difference
35% (traffic volume) 0.35 / 0.1 = 3.5 so 175% difference
30% (traffic volume) 0.30 / 0.1 = 3.0 so 150% difference
25% (traffic volume) 0.25 / 0.1 = 2.5 so 125% difference
20% (traffic volume) 0.20 / 0.1 = 2.0 so 100% difference
15% (traffic volume) 0.15 / 0.1 = 1.5 so 75% difference
10% (traffic volume) 0.10 / 0.1 = 1.0 so 50% difference
Taking these rough figures you need to have reduced the traffic volume to 20% of previous levels to counteract the increased speed through the village. Ideally you would need 15% to see a reduction in the likelihood of a pedestrian fatality. Allow for the fact that the truck traffic through the village is not reducing as much as the car traffic and the figures get depressing.
The above approach is simplistic at best but illustrates the perils of speeding in a village. We’ll leave parents collecting their children from school, as traffic whizzes past inches from them, for another day 
Here are some other figures to ponder…
If 100 trucks per hour were going through the village before the motorway at 35mph and now there are 90 trucks per hour doing 45mph what’s the difference in speed by trucks per hour?
100 x 35 = 3500
90 x 45 = 4050
4050 / 3500 = 1.16
So a net increase of 16% trucks by speed per hour.
I don’t think your figures are accurate but I don’t think they are that far off either. At aguess the traffic is prbably going 5 mile an hour faster on average so the figures for fatalities are going to be reduced a lot 35mph versus 40 mph being a significant difference.
But there again the traffic never went through the village at the speed limit so I guess it’s a question of sooner or later there will be a fatality.
B.
P.S. Can you verify that kinnegad is really upgraded?
[…] Sicilian Notes is asking what new ideas are there to prevent deaths. I’d argue we din’t need new ideas, we need enforcement. Currently trucks and artics are whizzing through clonard village in blatant disregard of speed limits. As I argued here, this alone negates the increased safety to pedestrians through reduced traffic after the M4 opening. […]