speed restrictions signs

[THE-SARGE]

According to the traffic signs regulations and general directions 2002, I understand that a road is de-regulated if the speed limit is above 30mph. If the road has been regulated for years as a 40mph limit and the council decide to make it a restricted road of 30mph. is it good enough after a number of years to simply rely on the lamposts being 200yards apart as in a restricted road without placing round speed limit signs. This seems to catching a number of people out as they still believe it to be 40mph. The local authority have put up some smatt red signs indicating the new limit.
as it was a de-regulated road can it now be returned to a regulated road without roiund signs

[ABerrant]

I am somewhat confused by the phraseology of your question (notwithstanding the lack of a question mark) however Schedule 19. PART II 11.(4)(a) of the TSRGD 2002 prohibits the use of repeater signs on a road subject to a speed limit of 30mph where there is provided a system of carriageway lighting furnished by lamps lit by electricity placed not more than 183 metres apart in England and Wales or not more than 185 metres apart in Scotland (i.e. lamp-posts 200 yards apart or less) but there must be signs at entry points to this road from roads subject to a different speed limit.

http://www.opsi.gov.u...0023113.htm#sch19pII2