Lane Assist in CN_NT_EU gmapprom.img?

Yes you actually do have a way to test. Put the device into Simulation mode (in 3590 that's Settings > Navigation and check "GPS Simulation") then set your location in a major European city, route to another major city which will use freeways/expressways and scroll thru the route by tapping the top LH corner then hit the down arrow every couple of seconds giving it a chance to show a junction view pic if available. London to Manchester will show several for example. I haven't checked if you've got the right map and JCV file by the way, the OEM map for EU 3590 is the NTU (Unicode) map. I'm not sure that ASR2 is available for the 'non-unicode' NT either.