Data supports a road safety focus on speed

— Link between speed and collisions is well-researched and strongly established.

Comment & Analysis: Speed of course isn’t everything when it comes to road safety but there’s strong evidence to support a focus on speed.

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One of the latest examples of dismissing speed is from motoring journalist Bob Flavin — I should say that I agree with him on a lot of things including the need for better enforcement around other road user behaviour, but one of the things I cannot agree with him on is how important the focus on speeding is.

In a tweet just before Christmas which quote tweeted the Garda results of their Slow Down Day he said: “99.76% compliance with the limits Well done drivers! Speed is not the problem.”

High-visibility enforcement results in lower speeds

Speeding enforcement with clearly marked GoSafe vans results in very location-focused lower speeds — the vans are usually easy to spot and other motorists nearly always flash their lights. There are also Facebook and WhatsApp groups dedicated to warning people of the location of speed checks.

On top of that, there are several reasons why speed vans don’t record valid detections including number plates being obstructed by other vehicles passing or dirt.

And it’s unclear how much of the enforcement is done on congested roads. And, on spotting a speed van or another driver flashing their lights, many motorists drop down to well below the limit (ie even 20km/h+ lower than the limit) and this tends to cause congestion on roads where or at times when there usually wouldn’t be.

So, there shouldn’t be any surprise that high-visibility policing results in a lower rate of crime.

Non-enforcement speed surveys show the opposite

In contrast, the latest ‘free speed’ survey by the Road Safety Authority found 78% of motorists speeding on uncongested 50km/h roads, and that jumped to 93% at weekends. This of course differs for different levels of roads including the design of the road, the level of traffic and the type of traffic etc.

As I reported in 2022: A new approach to the ‘free speed’ surveys has found that a far higher percentage of motorists are speeding in uncongested conditions than previously recorded by Ireland’s national road safety body.

But what was the change? The difference mainly involved moving away from more obvious handheld devices to automated traffic counters.

Similar automated traffic counters linked to speed display signs installed by councils around the country show that speeding is an issue. These counters have been showing how much speed is an issue for years, as this website reported back in 2016. But there’s a whole system of dismissing the impact and effect of speed.

The link between speed and collisions

It’s well established that speed is one of the basic risk factors in traffic. There’s a firm correlation between speed and the likelihood of collisions and the likelihood of serious or deadly results.

As outlined in the SWOV Institute for Road Safety Research factsheet on speed from July 2021:

“In case of a crash, higher speed results in greater impact, which increases the risk of serious injury [1] [2] [3] [4]. Moreover, at higher speeds, the braking distance is longer, there is less time to process and react to information [2], and, consequently, less opportunity to prevent a crash. Finally, at higher speeds, there is a large amount of information drivers have to process in a short time. If too much information is provided, they more or less automatically focus on information in their central field of vision. This focus is detrimental to observation and processing of information in their peripheral field of vision [5] [6].”


  1. While I think poor road design encourages speeding in several places, you can’t ignore that speed is the crucial factor in a lot of collisions, for the reasons set out in this article. There is a low-level campaign in Irish media to convince everyone that speeding is not, in fact, a problem, often conveyed through opinion pieces, letters pages and any other medium that doesn’t need to provide evidence for assertions.

  2. Exactly Ciarán. It’s impact is being downplayed. Far too many drivers are exceeding the posted limits with no regard for other road-‘sharing’ users. They are doing so with near impunity as the detection system relying on GoSafe vans is a busted flush, merely enriching those who own it at vast public expense.
    It is so ludicrous that the locations of the detection vans are posted on Garda website and you can see them on navigations systems’ displays!.
    “Safety cameras operate in areas where there is a history of speed related collisions known as speed enforcement zones. All zones are available on the Garda website and available for GPS Navigation providers to download”. The bonkers approach to road safety!


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