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  • Writer's picturebrianleddin

Contribution to Joint Committee on Transport and Communications debate -Wednesday, 19 Oct 2022

Transport Infrastructure Ireland's report: Impact of National Road Speed Limit Reductions on Greenhouse Gas Emissions

We have a situation where the average speed cameras have a significant impact on driver behaviour. It is true to say that when they are there, drivers will drive at the speed limit for the most part. However, this report does not look at actual speeds that are being driven on our network and, therefore, if that is the input assumption, the output of the report is absolutely flawed.

I mention that because it says there will be a small reduction in carbon emissions if we reduce the speed limits. We might look at the actual speed limits, however. I referred to other studies, including an EU study, which show that a reduction of 17% or 18% in carbon emissions comes about from enforcement of speed limits coupled with a reduction of 10 km/h on the motorway network. Therefore, it seems to me there is a huge risk that coming out of this report, policymakers feel it makes no sense to reduce the speed limit. It makes sense to reduce the speed limit, however, and put in rigorous enforcements such that people drive at the speed limit. I make that point not to undermine the results. The 1% or 2% reduction in emissions is still very important. It seems to me, however, that we can get more if we get the reduction plus the enforcement. I acknowledge that even if everybody drove at the speed limit today, that 1% or 2% is still important because we have to find those reductions across our whole transport system. I would urge caution, however. I am not saying TII is saying this. TII carried out this report and had a specific remit. It is really important that we acknowledge there are limitations to the report. It should not be said coming out of this committee that speed limits have a very minor impact. I was really disappointed by the headline from earlier in the year that stated there will be 35 extra fatalities. I am not saying TII is responsible for that. That assumes nothing else has been done throughout the network when, of course, we could have speed mitigation right throughout the network. This is not directed at TII but that headline leverages the tragedies that so many people across this country have suffered on our roads to push against any change in our speed limits. I am not putting that accusation at TII but more so at the media, which ran with that headline.


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