Lack of speed-limit data from Dublin City Council hampering “lifesaving” technology in cars

On Saturday morning, in Cabra, at Blackhorse Avenue, a 2025 Toyota Aygo X was caught between two competing realities.

It was about 10:33 am when the brand-new car and the city’s speed limits stopped speaking the same terms. 

Cruising legally down a 50 km/h main road, the dashboard suddenly screamed 30 km/h and flashed red and beeped. 

This was apparently because the car’s Intelligent Speed Assistance (ISA) camera had caught a glimpse of a side street’s 30km/h speed limit sign.

All new cars sold in Ireland have been required since July 2024 to have such ISA systems, according to the Road Safety Authority (RSA). 

The government’s road safety strategy calls them a “lifesaving” technology that it will prioritise. 

The RSA’s website says that, “Research indicates that Intelligent Speed Assistance can improve road safety, including reducing the number of drivers speeding, and decreasing the number and severity of road collisions.” 

The primary way such systems work is with the camera reading road signs, but dirty signs, or foggy weather can obstruct those – and so some vehicles tap into digital map data, a video on the site says.

The only thing is, in Dublin city, there’s no up-to-date digital map of what the speed limit is on each street.

This, despite laws that require Dublin City Council to have this data online for re-use in a machine-readable format 18 months ago.

“We are required to provide the data in a shapefile format that can be embedded within GIS and the MapRoad platform,” a council spokesperson said on 26 January. “This will be carried out.”

The council’s “gap year”

The EU’s General Safety Regulation (2019/2144) mandated that every new vehicle – like that Toyota in Cabra – must run ISA after 7 July 2024. 

But the European Transport Safety Council (ETSC), a Brussels-based nonprofit, has warned that ISA systems that rely on cameras alone fail sometimes, including when speed limits are implied by the type of road, but not actually signed. 

“Digital maps, linked to GPS information, are essential in these situations and are used as a critical backup to cameras in ISA systems in many new vehicles,” it said.

Dublin City Council’s machine-readable map showing the city’s speed limits was supposed to be ready over a year ago.

Under the EU’s High-Value Datasets Directive (2019/1024), transposed into Irish law in July 2021 (SI 376/2021), and under the subsequent Commission implementing regulation (2023/138) – the Council was required to publish machine-readable speed limits by 9 June 2024.

There was a digital map of Dublin and its speed limits, uploaded in 2013 to the Economic and Social Research Institute’s (ESRI’s) website. 

But that’s marked as “deprecated”. Jim Herries, a senior cartographer at ESRI, said on 25 January that "It's certainly outdated now”. 

In November last year, Dublin City Council responded to a  request under the Freedom of Information Act for a complete list of each street in the city with its speed limit by saying it doesn’t exist.

“There are no datasets that would facilitate matching this schedule of roads and streets or segments of roads or streets with their corresponding designated speed limit,” administrative officer Chris Carroll wrote.

Instead, he pointed to a 2020 pdf map of the city with different areas and roads coloured differently, and a copy of the 2020 speed limit bye-laws. 

The fallout of the delays in putting out a digital map goes beyond confused Toyotas. 

By keeping speed limits trapped in pdfs, the council renders the data useless for many others. It blocks researchers, and software developers, and stalls road-safety tools intended to save lives, like the ISA systems in new cars.

The Office of the Information Commissioner (OIC) acts as a regulatory referee, ensuring the public bodies don't treat public data, intended to fuel innovation and transparency, as private property. 

Re-use is the legal right to take data collected and recycle it as raw material for a new purpose, like the ISA system in cars. The law views this data not as a static record to be filed away, but as digital fuel that has to be shared.

The parent with a big purse

The Department of Public Expenditure oversees open data policy, and manages the national Open Data portal, a department spokesperson said on 23 January. 

It “supports public service bodies in implementing the National Open Data Strategy 2023–2027 and complying with the Open Data Directive and associated Implementing Act on High Value Datasets", the spokesperson said. 

But ultimately, "Public service bodies are responsible for compliance with the Open Data Directive," they said.

For more questions, they pointed to a specific person, recommending contacting the Smart Dublin Open Data Lead – Smart Dublin coordinates open data across the four Dublin local authorities – and cc’ing Dublin City Council’s press office. 

On 26 January, the team lead replied that, “Unfortunately, I have been informed by DC traffic that a machine readable version of the dataset does not exist. However, I am meeting with gis consultants and DCC traffic later this week on the topic. I will let you know timelines once the project has been scoped out”.

A council spokesperson at the press office quickly followed up with an email to say that “Individual employees and departments are not to be contacted directly”, and to give their own update on the situation.

“There isn’t a standalone GIS dataset for the Special Speed Limit Bye-Laws 2020 (Phase 4), which reflects the current speed limits,” the spokesperson said, but the council’s working on it.