The original incarnation of the Transport Model for Scotland (TMfS) was the Central Scotland Transport Model (CSTM) and was designed as part of the Central Scotland Transport Corridor Studies (CSTCS) project.

The coverage of CSTM was principally focused on the Central Belt of Scotland - from the Scottish-English border to Dundee and South Perthshire. Angus, Aberdeenshire, Aberdeen City, Moray, Argyll and Bute, the Highlands, the Western Isles and the Orkney and Shetland Islands were not included in the CSTM model. A number of versions of CSTM were created, the final version being CSTM3A.

In 2001 MVA Consultancy and David Simmonds Consultancy were commissioned by the then Scottish Executive to create TMfS as an extension of the CSTM series.

The initial version of TMfS (TMfS:02) had a 2002 base year. One of the key aspects of this new commission was the extension of the model to Aberdeen and the North East. Aberdeen, in particular, benefited from a detailed zoning system and had a relatively good representation of the strategic road network. There was also a separate sub-area model of Aberdeen and Aberdeenshire (the Aberdeen Sub Area Model - ASAM) created, using TMfS:02 as its parent model.

TMfS:02 had significant enhancements in data sources – new Roadside Interviews (RSIs) and journey time surveys were undertaken, additional network detail was added and new data sources were included in order to improve the calibration of the model. The zoning system was also adjusted so as to correspond with the zone boundaries of the 2001 Census output areas, thereby facilitating the incorporation of data from the 2001 Census and subsequent General Register Office of Scotland (GRoS) population estimates.

TMfS was expanded to include the remainder of Perthshire, Angus, parts of Moray, Aberdeenshire and Aberdeen City. However Argyll and Bute, the Highlands, most of Moray, the Western Isles and the Orkney and Shetland Islands remained external to the model.

The primary zonal detail enhancement undertaken during the TMfS:02 commission was the inclusion of a detailed representation of Aberdeen City. This meant that TMfS now covered all of Scotland’s cities except Inverness. However, the new zones added in areas such as Aberdeenshire were still relatively large. As a result, TMfS:02 does not capture a number of internal trips within this area.

Apart from the continued omission of the Highlands, Moray, Argyll and the islands, the most significant omission from TMfS:02 was local bus data for Dundee and Aberdeen.

TMfS:02 underwent a subsequent round of enhancements in late 2005 and 2006. The core objective of this programme was to re-base TMfS:02 to a 2005 base year (TMfS:05). As part of this process, additional network detail was added in a number of core areas, such as the M77 extension between Malletsheugh and Fenwick and the Glasgow Southern Orbital road. In addition, a large number of inter-urban public transport services were updated to their new 2005 timetables and routes, additional traffic count data was incorporated and new journey time surveys were undertaken. Approved Local Authority planning data was also collected and fed into the Transport, Land-Use and Economic Model of Scotland (TELMoS). The TELMoS projections were then rationalised to reflect the national forecasts produced by the General Register Office for Scotland (GROS).

In late 2006, Transport Scotland commissioned MVA Consultancy and David Simmonds Consultancy to a new three-year ‘Term Commission for the Maintenance and Enhancement of the Transport Model for Scotland’. The key aim of this commission was to deliver a new national model, complete with data improvements and a package of enhancements. However, a further aim of the commission was to support the existing use of the model amongst the User Group. Initially, the key application requiring TMfS-based support was the Strategic Transport Projects Review (STPR). A key premise of the STPR was that it was expected to cover the whole of Scotland. As such, in order to support the modelling needs of the STPR, and the TMfS User Group generally, TMfS:05 was extended to cover the whole of Scotland, the updated version being named TMfS:05a. TMfS:05a was the standard release version until the 2007 based enhanced modelling suite (TMfS:07) was completed in January 2009.

TMfS:05a provided a number of improvements over the TMfS:05, including:

During 2008 a new, more strategic, version of the national model, TMfS:07, was developed. TMfS:07 represents a step change in the quality of the model with a number of technical enhancements and a considerable quantity of additional data. TMfS:07 and TELMoS:07 will form the standard release version of the model for the foreseeable future. The enhanced functionality of the model and updated dataset will allow for more detailed and robust analysis.

A key feature of TMfS:07 is the new hierarchical approach adopted in model development, with a high-level national model and more detailed regional Sub-models. Over time, TMfS:07 will be supplemented by regional models, the first of which is the new Forth Regional Model. In line with TMfS:07 being more strategic than its predecessor, TMfS:05a, a number of changes in model form have been made, including:

Further enhancements to TMfS:07 include a georectified road and public transport network, High Occupancy Vehicle (HOV) modelling, Park and Ride as a separate mode in the demand model, and enhancements to TELMoS. The revised model has also benefited from the inclusion of a significant volume of new data.