Travel demand modeling is often taught using a 'bottom-up' approach—students first learn the statistical and theoretical foundations of modeling, and then work with individual steps of the model. Only after many courses do students run a complete travel demand model. In this article, I demonstrate a 'top-down' approach that I use in my introductory Planning Methods course. After a brief introduction to demand modeling, students run a simplified model and interpret outputs. While most of my students will not become modelers, this provides them valuable experience to communicate with modelers, understand the applications of modeling, and critically evaluate model outputs. 

In the transport system, we are facing several major societal challenges : saturated networks, massive maintenance needs, climate change, energy transition, nature diversity, digitization, and major housing challenges. These transitions have a significant impact on mobility. New questions and information needs arising from these transitions, which cannot always be adequately answered with the current modelling tools. This calls for a renewal of traffic and transport models and in the way we apply them in our decision making processes. The Dutch Road Authority (Rijkswaterstaat- RWS), part of the Dutch ministry of Infrastructure and Watermanagement, proactively responds to this challenges with its strategic model transition program, which will be conducted in the coming years.

In recent years, RWS has taken preparatory steps to work on such a program. Scientists have been consulted, the national model system (LMS/NRM) has been reviewed, and interviews with people in the (policy) field have been conducted. With this input, RWS has performed an analysis that serves as the basis for a thorough renewal. Additionally, the current tools are difficult to manage and keep up-to-date in their entirety. Therefore, it is necessary to give an impetus to realizing a renewed modelling system to:

§  improve the validity of the models;

§  better respond to new questions and information needs;

§  improve the management and application of the models (more robust, efficient, transparent);

§  adapt to the changing requirements and technical possibilities of this time.

The renewal tasks are divided into four clusters, each with some examples:

1.     Behaviour in time and space: Due to major housing construction tasks, strong spatial dynamics between living and working are expected. Additionally, there are limits to the amount of available time and money that can be spent on travel. Budget constraints regarding time and money are not explicitly included in the models. Furthermore, stronger differences between the days of the week in traffic congestion have emerged due to COVID-19, reducing the significance of the average working day.

2.     More diversity in behaviour: Digitization of society leads to changed activity patterns for different target groups. The focus on sustainability and the rise of electrification of transport modes lead to behavioural changes regarding mobility.

3.     Heavily loaded networks: As networks become more saturated, the complexity in the dynamics between traffic demand and supply increases. This puts the principle of user equilibrium under pressure.

4.     Decomplicating: There is a tendency to make models increasingly complex. On the other hand, there is a need for more manageable, transparent and shared models that can also handle different scale levels.

These renewal tasks have been processed into a preliminary program with renewal projects for the period 2024-2028, including necessary resources (people and money). From April 2025, a partnership with market parties and knowledge institutions will start to implement the renewal program.

The projects for this year are aimed at making several fundamental choices during 2025