In Europe maps no .gap file and all works with texts, why must gaps be necessary for US maps?
this could very well be due to a restriction imposed in the program specifically for certain regions of the world (for mysterious geopolitical or commercial reasons)

without .gap files are all cameras registered in speedcamsUSA.txt.txt are visible on the map
this can come from a mechanism for excluding .txt to privilege .gap files

as long as equivalents for European countries are not available, it is not possible to assert anything with certainty on the coexistence of the two formats