Why does the core model not allow me to model scenarios such as when there is a crossing on a road that blocks straight-ahead traffic?
The core models used in PICADY have some restrictions which mean that it is difficult to combine the various sub-models which handle, for instance, major road blocking and pedestrian crossings.
However, in Junctions 9 and Junctions 10 you can turn switch into Lane Simulation mode and then you CAN turn on various features at the same time. This is also often the case for other situations in ARCADY, PICADY or OSCADY where there are difficulties with the core models; Lane Simulation can often be used as an alternative.
For details of Lane Simulation Mode in PICADY, ARCADY or OSCADY, please see the User Guide.