Sorry Martyn, there isn't any way to edit route tags at present. I thought we already had this on our Feature Request list but it doesn't seem to be there so I've added it now (number 95) so that people can vote for it.
Is there any way to edit a tag name? There are times when it would be good to be able to do this without changing the tags on every relevant route, e.g.,:
- Correcting a spelling error
- Consolodate two tags into one