TMfS/TELMoS is a multi modal strategic Transport and Land Use modelling suite that contains an extensive database of road, public transport and ferry supply information, travel demand data and land-use information. It has been used extensively to provide input to a number of major Scottish transport scheme and policy applications. In addition, it has also been used to provide supporting information for regional and local area models within the TMfS modelled area.

TMfS works as a four stage demand modelling procedure programmed using TRIP/CUBE software. It models Mode Choice, Destination Choice, Time of Day Choice and Route Choice. The route choice provides costs for the demand model and also data for operational analysis. The associated Land Use Model called TELMoS, provides planning data inputs to the Travel Demand Model.

Highway Model - The highway model convergence has two parts. Firstly Global convergence is achieved when the cost of the network changes by less than 0.01 on 3 successive iterations of the model. Once Global Convergence of the network is achieved then Link Based Convergence is examined. This is done by checking whether 95% of the links in the network change in flow by less than 5% on 3 successive iterations. Once both types of convergence have been achieved then the model is said to have converged. Demand Model - The demand model reaches convergence using the method of Trip Damping. This means that for every loop of the demand model the solution is made up of the current solution and those from previous loops. For example on loop 2, the solution is 50% of the solution from loop 1 and 50% of the solution from loop 2. On loop 3 it is 33% of each loops solution and so on. From testing 5 loops of the demand model have been deemed to be enough to reach convergence.

TMfS currently uses the TRIPS Voyager software platform, while TELMoS (the land-use model) makes use of Delta.

The Road Assignment Model is validated against a whole range of counts that were not used in the calibration process while additional validation takes place against journey time surveys. Validation of the Public Transport Model is undertaken using a public transport surveys and counts, LENNON data and bus journey time analysis.