On the left is a photograph which I clicked in a mosque. It is about a 'Zaroori Elaan' [Important Announcement] that the particular mosque is now 'Khud-kafeel' [self-sustaining, self-supporting] and donation must not be paid to any person who demands money either for renovation or for other needs of the mosque.
The language is quite standard and it can even be termed chaste Urdu. Roman Urdu was used extensively before independence also, particularly, in Indian Army where it was the standard language used for communication.
Urdu script is no longer commonly seen in public places in most parts of the country, except a few Cities. Even in Muslim ghettos in most towns, Urdu signboards are now becoming a rarity.
As far as decline in Urdu signboards is concerned, one of the reasons is that painters proficient in Urdu aren't easy to find at all times. Lack of Urdu medium schools and fewer private schools teaching Urdu as third language compound the problem.
Of course, other reasons are well-known and oft-repeated. Situation in UP, Bihar and other parts of North India are not favourable for the language. In Southern India, Urdu continues to flourish in pockets in Karnataka, Andhra Pradesh and even Tamil Nadu where the region around Vellore has Urdu-speaking populace.