No, it's harmful and useless mapping for the renderer. This time, please try reading the wiki page. Perhaps your friends @MKBE_ and @MKBE_2 can help you out?
osm.wiki/Tagging_for_the_renderer

Please leave a meaningful changeset comment.

If this *really* is access=no, how did the cars clearly visible in the aerial imagery get there?

If no access *at all* is allowed on this service road, how did the vehicles clearly visible in the Bing aerial imagery get there?

Then it isn't access=yes. If you don't know how to add a conditional restrictions, you can read the wiki and ask for help on the forum.

osm.wiki/Conditional_restrictions

This has a note tag with "This section of road prohibits all motor vehicles other than buses", yet you *still* deliberately set it to motor_vehicle=yes? Reverted.

It wasn't but it is now.

That wasn't OSM's problem, until you added a fictitious access restriction. Reverted.

Maybe it does, but it still exists. Restored.

Adding access=yes to a street which has "no motor vehicles" signs (with exceptions) effectively turned Drapery into a through route for all transport modes. However, it did not have access tags which matched the signed restrictions before you edited it either. Hopefully this is now correct.

The Bing street side imagery showing the restriction signs is at https://www.bing.com/maps?toWww=1&redig=0E61462A315B4089ADF0DBB49CFAA9E5&cp=52.238538%7E-0.897411&lvl=19.8&mo=om.1&pi=-11.1&style=x&dir=136.9

Mini-roundabouts (traversable centre, road marking per TSRGD diagram 1003.4) are tagged as nodes rather than as circular ways as routing software needs to be able to differentiate between them. I realise that it is tempting to re-map them so that they look better on the map, but it is incorrect and unhelpful to data consumers. Reverted.

Mini-roundabouts (traversable centre, road marking per TSRGD diagram 1003.4) are tagged as nodes rather than as circular ways as routing software needs to be able to differentiate between them. I realise that it is tempting to re-map them so that they look better on the map, but it is incorrect and unhelpful to data consumers. Reverted.

Unfortunately adding in incorrect access=yes tag to the Luton Dunstable Busway could have adverse effects on other data consumers. Reverted in changeset/154376239

Mini-roundabouts (traversable centre, road marking per TSRGD diagram 1003.4) are tagged as nodes rather than as circular ways as routing software needs to be able to differentiate between them. I realise that it is tempting to re-map them so that they look better on the map, but it is incorrect and unhelpful to data consumers. Reverted.

Mini-roundabouts (traversable centre, road marking per TSRGD diagram 1003.4) are tagged as nodes rather than as circular ways as routing software needs to be able to differentiate between them. I realise that it is tempting to re-map them so that they look better on the map, but it is incorrect and unhelpful to data consumers. Reverted.

The whole point of the Luton Dunstable Busway is that general traffic is excluded, so access=yes would rather defeat the point. Reverted.

Reverted and repaired. A section of road with clear "BUSES ONLY" road markings cannot be access=yes,.

The tagging you probably wanted here is access=customers. A petrol station forecourt with motor_vehicles=no seems unlikely. Reverted.

Thanks for adding the bridges. Original access tagging of motor_vehicle=permit reinstated in changeset/154360323

Reverted and updated. It is correct now.

No, it was mapping for the renderer. Reverted in changeset/154344167