The architecture of the digital twin mobility model is centered around the concept of an Origin-Destination (OD) matrix. An OD matrix can be seen as a list or matrix which establishes the connection between the location where people work with the location where they live. Therefore, these matrix values can be seen as a proxy of the probability of traffic between two zones. The locations can be defined in terms of grid elements or geographical units. In addition, travel habits, i.e., the probability of using a mode for a certain activity is also a key concept in the mobility model implemented in the digital twin.

The model builds on the following key elements

• The crowd-sourced open-source Open Street Map (OSM) is imported to generate the network using road type, direction, and capacity.
• Norwegian Roads Authority (SVV) hourly traffic measurements at key locations are dynamically updated daily, with traffic direction, vehicle length, and category
• The HBEFA database of emissions is used to quantify the CO2 emissions for each scenario based on the modal distribution and the energy mix of the country.
• The calibrated MATSIM model validated with the traffic measurements from C. It serves as a base for the model when users (e.g., urban planners) play with different parameters.
• An infinity of what-if scenarios can be simulated. Which refers to population growth without changing lifestyle and travel habits; “Slow Zero” relates to some change in habits towards a more sustainable living.