This is of no importance for you, more for the developer. The route author can customize the look of the 2D map (colours, train and signal sprites). This red cross symbol shows the location of a route network asset (sometimes invisible signals or signal block splitters) which are needed for the dispatcher to work. The symbol helps the route builder to find these spots again. (CSX Hanover for example uses signal block splitters which are disguised as a small pile of rocks, hard to spot in 3D view.) Most of the time, they are undefined or removed after route building. You will find them in Assets\<Provider>\<Product>\System\map\mab.bin e.g. Assets\RSC\LiverpoolManchester\[LiverpoolManchesterAssets.ap]System\map\map.bin Here redcross.TgPcDx is used for marking the location a failed signal, this is Railworks' definition. A failed signal can be such a track network thing as mentioned above. Kuju implemented more into Railworks than what actually has been made use of it seems. If you look at the other definitions (AutoRed... etc.)
