The Report describes the development of a strategic urban transport planning model known as CRISTAL. The object is to enable rapid comparisons to be made of the traffic benefits of alternative transport policies or investment plans when these can be expressed in a sufficiently generalized form. The model deals with four passenger travel modes and with road goods vehicles and uses the concept of the generalized cost of a trip, i.e. the sum of time and money costs. The representation of demand and modal splits permits straightforward economic evaluation. A distinctive feature of the model is the use of a simplified geographical representation, in which the actual road and railway networks are represented by idealized transportation corridors of a symmetric ring and radial form. This simplification reduces the data handling requirements and therefore speeds up the computing process. The first part of the report describes the logical and theoretical structure of the model. The second part describes how the model has bben set up to represent the Greater London area and lists the numerical values of the various parameters. Possible applications of the model are also discussed, and relevant data presented.