Why are road markings on the roundabout encouraging overtaking when all roads leading off are single carriageway?

I take the lower Treluswell to Truro road daily. Indicate right, cruise around the roundabout, indicate left to take the turn off (at the last minute I hasten to add) only to find (several times now) a vehicle on my right. Presumably thinking it’s a dual carriageway! Gets teasey when they have to pull in behind me and very often then tailgate me until Carnon Gate roundabout when they can thunder off past.

I believe I witnessed the aftermath of an “argy-bargy” on Sunday, January 7, 2018. Two cars parked up on the roundabout, all occupants out and on their phones. Worse to come when holiday markers arrive and don’t know the roads.

Miss K Rundle,

Dracaena Place

Falmouth