Garmin nüvi speed limit

Hi there,
I was accustomed to see the speed limits (by example 80 in a red circle) on the screen of the Garmin nüvi when using the original Garmin maps.
I now tried
eu_rout_gmapsupp1.img und eu_rout_gmapsupp2.img from
on a nüvi 2455 and a nüvi 1340
Unfortunately, the screen doesn´t show neither the speed limit nor the actual speed turning red when exceeding the speed limit.
Some years ago, there was a post telling this feature worked only with the original Garmin maps.
Is there a solution for this problem now?
tks in advance

No, as far as I know this only works with NT maps and mkgmap is not capable to create such maps.

Thank you ligfietser. I´m afraid you´re right.