Usually the Speedcams icons appear on the map only if there is a txt file with the related TYPE, (15), in the speedcam folder, I do not know if Congestion Charge Zone is also included in .spc files.
If Pongo does not solve this bug you should cancel this icon from the speedcam.zip file, is in the bmb format for iGO and it is in the files speedwarn0 and speedwarn1 in the folders hdpi, ldpi, mdpi, xhdpi, xxhdpi, xxxhdpi. You must use either the iPAQ31 or Dview program to turn the image into png, edit it and then convert it back to bmp for iGO.
I used this skin just to test the Average Speed Camera and the road seemed big enough, however, in Arimi's skin there is a folder "width_road_xxx" with some width_road files inside, just try and find the one that's right for you.
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