CityTwin - urban digital twin for public administrations

WHAT IT IS

A digital twin of one community. Not a chatbot that knows everything.

An urban digital twin is a digital model of the city, with its coverage and its limits on display, that you can question and on which you can test decisions before taking them. CityTwin works in an environment dedicated to a single community, using documented data that carries its sources. It is meant for public administrations, urban planners and funding officers: anyone who needs decisions grounded in evidence rather than assumptions.

Tied to one community

The assistant works on the community's data model: areas, projects, problems, indicators and sources. It is configured not to use information that the sources in the city model do not support.

It stays within the community's data

Answers are limited to the community's data and domain. Where the model cannot support an answer, the assistant states that the data is missing.

Your data, kept safe

Data provided by the institution and the resulting model can be exported in open formats, under the conditions agreed in the contract and in line with the licences of the sources used. Primary hosting and AI processing take place in the European Union, with data protection built in by design.

THE PRINCIPLE

Sources first, conclusions after

Generative models can produce plausible answers even when the information behind them is thin. CityTwin is designed to tie every answer to the sources built into the city model, so the answer can be verified before it is used in a council meeting, in a public document or in a funding application.

Answers point to their sources

The answer cites the document, the map layer or the indicator it comes from. You go straight to the source and check it yourself.

It says "I do not know" when it does not

What is missing from the data is stated as a gap, not invented. Anything the data cannot support is flagged and has to be verified before use.

Fact kept apart from assumption

What is measured, what is estimated and with what degree of certainty: all marked explicitly, with a confidence level. No false precision.

Support for the reasoning, not a verdict

You get options and arguments with sources; the decision stays with the person. It does not replace the specialist, it prepares the ground for them.

RESULTS

What the administration gains, concretely

The same public data, turned into time saved and decisions you can defend with documents.

Easier funding applications

You build the case for European or national funding on vulnerable areas, indicators and cited sources. You argue with figures and documents, not with stories.

Decisions with sources, not opinions

Every answer comes with the source from the city's documents. You defend a project in front of the council with verifiable evidence, as support for the decision rather than a verdict.

Simulate before you spend

You test the impact of an investment on the 3D map, a car park, a school, a transport stop, before you commit budget to it. For example: where to place a nursery so that it covers the largest number of children within a 15 minute walk, computed on the real street network.

HOW IT WORKS

From scattered documents to decisions backed by evidence

Four connected stages, from collecting the data to analysing and presenting the results. It does not replace the specialists, it helps them see faster and more clearly.

Collect - public documents, open data and geographic information from the available sources, including the urban geometry mapped in OpenStreetMap.

Model - the city becomes a set of entities and relations (areas, projects, problems, services, indicators), each with its source and its degree of confidence.

Ask - you put a question in plain language and the assistant answers from the sources built into the city model, with sources, assumptions and gaps stated explicitly.

Decide - the answer appears on the map, you simulate interventions, compare scenarios and export a report for the meeting or for the funding file.

DATA CONTROL

The city's data remains the city's data.

We know what every administration fears when it signs with a software supplier: being tied to it and losing sight of its own data. With CityTwin it is simple. If one day you want to leave, you take everything with you, the model, the data, the history, in open formats. No obstacles, no negotiations.

The data stays with the city

The model is exported as an open JSON file with a public schema; the geographic layers inside it use standard GeoJSON, so they can be reused in any GIS. Data provided by the institution and the resulting model can be exported under the conditions agreed in the contract and in line with the licences of the sources used, with no proprietary formats to tie you to us.

Your data stays portable

Open standards, not a black box. Data and services stay interoperable through JSON, GeoJSON and a WFS endpoint, so that you do not depend on a single supplier for a critical piece of infrastructure.

In the European Union, with data protection by design

Primary hosting and AI processing take place in the European Union. Some auxiliary technical services may operate globally, under the conditions described in the privacy policy. No advertising cookies, no profiling. Security measures informed by relevant NIS2 requirements; no certification claimed.

Layers derived from OpenStreetMap are published under the ODbL licence, with the corresponding attribution. The full licence terms are on the data licensing page, in Romanian.

PUBLIC DEMO

Open the map now, without an account

open to anyone

The public demonstration lets you explore the model built for Brașov directly: the 3D map, the thematic views (general, mobility, climate, safety, 15 minute access, energy, heritage), the analysis themes that recolour the map by indicator, the side-by-side comparison of two themes, presentation mode and the basic functions of the investment simulator. Its limits come from the demonstration configuration and are shown in the interface. Advanced analysis, saved and compared scenarios, the command centre, automated alerts, the WFS service and reporting are available to partner institutions. The demonstration is not an official implementation by the Municipality of Brașov, and the interface and the answers are in Romanian.

Open the demonstration map See a sample report

THE FULL VERSION

What partner institutions get

available to partner institutions

Partner institutions get a CityTwin workspace dedicated to their community, configured on local data, documents and priorities.

AI analysis on the city model partner

You ask a question in plain language and get an answer with sources, assumptions and gaps stated explicitly.

The simulator without the demonstration limits partner

You place investments on the map, 12 types from a nursery to a cooling point, and see which areas and which problems they cover, computed on the real street network through walking isochrones rather than a circle drawn around the point.

Scenarios saved and compared partner

You save a simulation with a name and an objective, build another one and put them side by side. Scenarios stay on the city's server, not in someone's browser.

Automated alerts partner

Trends and threshold warnings (WHO guidelines, EU limits) come out of the automatically updated series, with the calculation method written next to each alert. Climate forecasts are still under construction and are not delivered.

Command centre, reports and export partner

An analytical dashboard over the model and the connected sources, plus a report for the meeting file or for the funding application with the sources indicated, and export of the model as JSON with a public schema, GeoJSON layers and a WFS service for GIS clients.

Users with roles partner

Colleagues work in the same workspace, each with their own role and level of access.

How we work with data: we start from the city's public data, documents, maps, indicators, and turn it into a decision support tool that stays up to date and in which the information points to the sources it relies on. Coverage and accuracy grow as the city brings in more data, and the final decision always stays with the person.

WHO IT IS FOR

Who uses it and what they get

Mayors and public administratorsPrioritise investments and export a report with sources, ready for the meeting file.

Urban planners and chief architectsCheck a location against the reference documents: what is reachable within 15 minutes, computed on the real street network.

Funding officersBuild funding applications on vulnerable areas, measured data and cited sources.

Journalists and civic organisationsCheck what the city has promised: the targets assumed for 2030 and the projects that match them.

ResidentsUnderstand their own neighbourhood: which problems are officially recognised and which projects concern it.

Universities and researchersStart from the city's open data for their own analyses.

QUESTIONS

Frequently asked questions

The questions public administrations ask us most often, answered with what is already published on this site.

What data does CityTwin use?

The city's own public documents and open data: the urban master plan, the mobility plan, strategies, the budget and indicators, plus open map geometry from OpenStreetMap and European Earth observation layers. The refresh frequency is shown per source: some series are daily, others periodic or historical. The history is kept and a monthly version is archived. Coverage and accuracy grow as the city brings in more data.

Does the city keep its own data?

The institution keeps control over the data it provides and can export the resulting model: open JSON with a public schema, and geographic layers in standard GeoJSON, reusable in any GIS. Export follows the contract and the licences of the sources, and third party layers such as commercial traffic, satellite imagery and terrain tiles are not transferred with the model. No proprietary formats that tie you to us.

Where is the data hosted and where does the AI processing take place?

How do I check whether an answer is correct?

Each answer cites the document, map layer or indicator it comes from, so you can go straight to the source and verify it yourself. What is missing from the data is stated as a gap rather than invented, and what is measured is marked separately from what is estimated. CityTwin supports the reasoning behind a decision; the decision itself stays with the person who makes it.

What can I try without an account?

The public demonstration built for Brașov: the 3D map, the thematic views, the analysis themes and their comparison, presentation mode and the basic functions of the investment simulator. AI analysis is closed in the demonstration. The interface and the answers are in Romanian.

What do partner institutions get beyond the demo?

A CityTwin workspace dedicated to their community, configured on local data, documents and priorities: AI analysis, the simulator without the demonstration limits, scenarios saved and compared with each other, the command centre, automated alerts, report export, a WFS service and users with roles.

What do we need in order to start a pilot, and what happens after we ask?

The basic public documents are enough to start: the urban master plan, strategies and the budget. After a request, we get in touch within three working days, go through your community's public data together with no commitment, and then send a concrete proposal: what the digital twin of your city would look like, the first report generated from its data and the conditions for access to the full version.

Is the Brașov demonstration an official project of the city hall?

No. It is built from public data and documents about the municipality of Brașov and does not represent an official implementation by the Municipality of Brașov.

Want a digital twin for your community?

The Brașov model was built from public data and documents about the city. An initial demonstrator can be prepared the same way from the public data available for your community; its scope and quality depend on data coverage and licences. Tell us about yours and we will usually get in touch within three working days.

Write to [email protected] Contact form (in Romanian)

Developed and operated by the Romanian Smart City Association (Asociația Română pentru Smart City), arsc.ro. Integral Business Center, Bd. Pipera nr. 1-IA, Voluntari, Ilfov, Romania. Phone: +40 31 425 42 63.