The Tour-Based Strategic Transport Evaluation Model (TB-STEM) is a next-generation forecasting tool developed by DTMI, replacing the traditional trip-based Strategic Transport Evaluation Model.
What is TB-STEM?
The Tour-Based Strategic Transport Evaluation Model (TB-STEM) is a next-generation forecasting tool developed by DTMI, replacing the traditional trip-based Strategic Transport Evaluation Model. It helps us to better understand peoples’ weekday travel in the Perth greater metropolitan area.
Unlike the traditional model, which treated individual trips as separate and unrelated, TB-STEM uses a tour-based approach that represents a person’s linked travel throughout the day. A tour covers a complete journey that begins and ends at home, such as travelling from home to work, then to a shop, and back home again. This better reflects how people plan and undertake travel in real life.
The model forecasts future travel patterns through to 2051, including:
- Tour generation - whether and how often people travel
- Tour destinations - where people choose to travel
- Mode choice - how people travel: by car, public transport, walking or bike riding
- Route choice - which roads or public transport services people use.
Models like this are an important part of robust, evidence-based decision-making. Model forecasts provide valuable insights to support transport planning, infrastructure investment, and economic assessment of major transport initiatives and policies.
What TB-STEM does differently and why it matters
TB-STEM shows the travel behaviour of individual households and people across the region, rather than relying on broad area averages. By representing travel at such a detailed level, the model can provide a more realistic understanding of how different people and households make travel decisions. For example, the model can analyse travel behaviour across a range of household and demographic groups, including:
- Annual household income
- Under $33,800
- $33,800 to $65,000
- $65,000 to $104,000
- Above $104,000
- Household characteristics
- Household size
- Number of workers in the household
- Household life-stage
- Retired households: households containing one or more retired persons
- Families with children: households containing children aged 18 years or younger and no retired persons
- Other households: households without retired persons or children
Consequently, TB-STEM provides more reliable forecasts of:
- Traffic volumes on roads and highways
- Public transport demand
- Passenger boardings and alighting at individual stations and stops
- Travel demand by time-of-day
- Travel patterns for different household and demographic groups.
Decision-makers can examine how the benefits and impacts of transport projects can differ across different income groups, household types and communities, supporting more informed and inclusive planning decisions.
Responding to travel behaviour changes
Travel behaviour has changed since the COVID-19 pandemic and due to other trends, such as new technologies. In Perth, and many other cities around the world, more people are:
- Working from home
- Shopping online
- Studying and training from home.
TB-STEM is designed to reflect these evolving behaviours by incorporating the influence of remote activities on travel demand. This capability allows the model to better represent current travel patterns and improve future forecasts in an environment where work, study and shopping choices, and other travel behaviours, continue to evolve.
Looking ahead
DTMI developed TB-STEM to provide a robust and flexible framework for analysing travel demand at the household level. As travel behaviour, technology and land-use patterns continue to change, the model will be regularly updated to maintain its accuracy and relevance.
TB-STEM will continue to provide valuable insights that support long-term transport planning, infrastructure investment and policy development, helping the State Government build a more efficient, accessible and sustainable transport system for WA into the future.