Would a speaker of a Scottish (or any other Englsih) dialect be dubbed or subtitled in British TV

Subtitles are generally available in British TV, to help people with hearing loss - and when a strong regional or national dialect is involved it is common for people to switch them on, tomake it easier to makem sense of what is being said.   

For example when the great Rab C Nesbit was being shown...

(The subtitles in that case would have been in Glaswegian Scots, not translated into standard English, but it was a lot easier to follow the man in black and white print.)