Sir, – The introduction of speed-over-distance cameras ("Speed-over-distance cameras to go live on stretch of M7", News, April 25th) is to be welcomed, given the significant reduction in killed or severely injured motorists experienced in other jurisdictions adopting this technology. However, the system appears to have a drawback if it is to be relied upon exclusively to detect speed limit breaches. A motorist could choose, for example, to travel half the journey between the camera points at, say, 10 kilometres per hour (km/h) over the 120 km/h limit and the remainder at 10 km/h below it. Overall, the journey is completed at a recorded speed-over-time of 120 km/h, masking the fact that for half of the journey the speed limit was exceeded. Speed between the tracking points also requires monitoring. – Yours, etc,
TIM O’LEARY,
Carrickmines.
Dublin 18.
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Sir, – The recent announcement of yet more investment in speed surveillance technology is another failure of data. Understanding causal factors is critical in the design of road safety measures, but we continue to fail in providing relevant causal statistics in Ireland. Data is either unpublished, withheld for data-sharing policy reasons, or “internal reasons”, to the point that the Garda Síochána, announcing the measures, chose to select UK statistics instead. Looking at those statistics, it appears that less than 10 per cent of all serious road traffic accidents had “exceeding the speed limit” as a causal factor in 2020. Mostly the problems there were down to driver error. We in Ireland don’t have any proper science to understand why road traffic accidents happen, so we base our safety investments on a hunch, and cross our fingers that things like car and road technology improvements (or a pandemic!) improve the numbers.
The Garda emphasised the impact of weather on accident propensity, without recognising that speed limits are often irrelevant in inclement weather. For example, sticking to the 120km/h limit in a hailstorm is usually unwise. How will speed limit enforcement and average speed cameras improve adverse-weather safety outcomes? Dynamic speed limits driven by weather might be a better idea. What about legally requiring access to speed data in on-board computers, present in most modern vehicles? The State needs to invest in data systems, data science and competent assessments in order to guide investments. Otherwise we are wasting money, imposing unnecessary and ineffective measures, and fooling ourselves into thinking we are being effective. – Yours, etc,
ANTHONY BEHAN,
Killeagh,
Co Cork.