i find the duel carriageway 40mph through town a lot safer at rush hour, than going along the industrial estate road single carriage way 40mph. as long as you do not trundle along the gutter and make the cars do proper overtakes, not just squeeze by.
nether are pleasant but cars and vans do insane things

to get past you, on the industrial estate, usually to turn immediately left so quickly you have to hit all the brakes or run in to them
i have a bit of hassle at the end of the duel carriageway as it splits in to three, they have put traffic lights on it now and a lot of drivers in the cars seam to believe that bikes are not allowed in the middle lane for going straight on

you just have to be firm indicate with a proper full arm out and pull across looking the driver behind in the eye if you can and ride in the centre of the lane, it becomes easer with the miles a relaxed confidant rider seams to have the ability to slice through traffic and quickly develops a "ho my god what is this twit going to do" sense.
with the big roudabouts it is all about eye contact, have they seen me or looked through me?