We introduce an adaptive network for public transport route optimisation by scaling down the available street network to a level where optimisation methods such as genetic algorithms can be applied. Our scaling is adapted to preserve the characteristics of the street network. The methodology is applied to the urban area of Nottingham, UK, to generate a new benchmark dataset for bus route optimisation studies. All travel time and demand data as well as information of permitted start and end points of routes, are derived from openly available data. The scaled network is tested with the application of a genetic algorithm adapted for restricted route start and end points. The results are compared with the real-world bus routes.An adaptive scaled network for public transport routes As the layout of the street network is essential for the design of bus routes, it is important that an instance network sufficiently reflects the characteristics of the street network. We therefore propose a network design procedure which scales down the network to a size manageable for meta-heuristic-based optimisations, while at the same time preserving the characteristics of the urban street network. Scaling down an urban street network is desirable principally to restrict the computation times needed for the passenger objective, which is usually the main bottleneck and leads to an increase of the run time with f (N 3 ) , N being the number of nodes in the network [see Mumford (2013) for a full explanation]. For our modest desktop set up, 1 we determined 500 nodes, which would result in a runtime of about 600 h, to be the upper-most limit for practical work.The down-scaling of the street network is achieved by devising simple and robust rules applicable to all urban layouts. The procedure further includes the identification of potential terminal nodes, an aspect vital for route design in an urban context.We will limit this work to instance generation and route network optimisation with restricted start and end points, as it is part of an incremental approach to more realistic public transport network optimisation. Our generation procedure is used to produce an instance for bus route optimisation in the extended urban area of Nottingham, UK. Further, a route initialisation procedure and a modified heuristic route optimisation algorithm, both specialised for work with restricted route start and end points, are applied to the generated instance. The optimisation results are compared to the real-world bus routes. 2 The main contributions of this paper are as follows:1. A novel methodology for generating an instance dataset, by systematically scaling down a street network and utilising census data (see Sect. 2). The generated instance will be published online for free use for all researchers. 2. An additional methodology for transforming pre-existing public transport routes to fit the scaled-down street network (see Sect. 4). 3. A multi-objective genetic algorithm modified for restricted route start and end points, to allow direct compariso...