What is transport modelling?

Transport modelling fundamentally involves analysing current conditions, identifying important variables and forecasting projected outcomes. Models are developed using appropriate analytical frameworks that align with each project’s complexity and strategic goals. They are delivered either using a standard industry platform or involve development of a bespoke tool to get to the analysis desired.

The value of a transport model goes beyond the model, driving impact in how its outputs are applied. Realising this value requires specialist experience to interpret inputs, select parameters and analyse results effectively.

Transport modelling typically follows the traditional four-step approach to estimating travel demand. This includes estimating the number and purpose of trips generated by discrete areas (zones), estimating the distribution of where those trips travel to, selecting the transport modes for each trip and then assigning the trips to the transport network based on traffic conditions.

Transport demand models will typically be multi-modal, in which case they will include private vehicle, commercial vehicle and public transport trips with some consideration of active travel modes. Other types of models may specialise in certain travel modes, providing greater detail and insight into the particular mode that is modelled. These include highway assignment models to predict how well the road network performs, pedestrian models that forecast movement in bus/rail stations, including boarding, alighting and crowding, as well as freight models that predict the movement of materials and goods, and active transport models for estimating cycling or walking demand across a network.

Simulation models, a further sub-set of transport models, can model individual vehicle or person movements in even greater detail to support detailed planning and design. Models for predictive road safety analysis have also been developed.

In Canada, area-wide microsimulation was applied using VISSIM in the Gatineau Transit Priority Project to assess how proposed transit priority measures would affect intersection performance and guide future upgrades. Similarly, the Stevenson Widening Study used focused microsimulation to evaluate the impact of a future Bus Rapid Transit (BRT) system on congestion at a key intersection.

Using pedestrian simulation models like Legion, busy transport interchanges, Glasgow Queen Street can be modelled that visualise people flow for new and existing developments, including construction phases. This model provides added value for stakeholder engagement, allowing clients and communities to see and interact with projected outcomes in a visually compelling way.

Transport modelling is a powerful tool for shaping mobility systems, but its effectiveness depends on navigating a range of technical and strategic challenges. These include:

Transport modelling is rapidly evolving as computational power increases and big data becomes available. Location-based data has enhanced our understanding of travel behaviour, enabling models that reflect not only where people go but also why they travel.

Current modelling approaches also consider how land use, parking demand, transit pricing and other factors influence travel decisions. These insights support more informed choices around infrastructure, policy and investment.

Transport modelling work involves both the use of industry-standard software and the development of custom platforms tailored to specific project needs. Depending on the requirements, tools such as AIMSUN, VISSIM or Synchro may be used for established workflows while script (for example, Python) or Excel-based models, for instance, are built to address more specialised challenges.

Transport modelling helps shape resilient, efficient and inclusive mobility systems. We combine deep technical experience with a nuanced understanding of land use, economic drivers and community needs to deliver models that drive meaningful transportation management solutions.

Whether you're planning for growth, improving safety or responding to disruption, our tailored modelling solutions can help you take decisive steps towards your goal.