Road speeds are generally stored as a speed per road class, where road class is a number from 0 to 31 and part of the attribute field.
The dialog allows you to add, modify or delete road classes and the corresponding speed.
You can also define if the speeds are in km/h or mph. Changing this do NOT recalculate the values.
Information is stored in Spd-files, which have the same format as in RouteFinder 5 and RW Net 4, with the exception decimal numbers are not allowed in the editor above.