Why the Y?

Exeter is often strange in its approach to street numbering and naming. I pity the poor postman - and deliverers of election material.

The usual convention of opposite sides of the road being odds and evens is often flouted by consecutive numbers - neighouring streets are often a mixture of odds/evens and consecutive, Who decides this?

Then there is the case of the first or last house in a street not being in the correct street, but in the street around the corner. To my way of thinking, 1 Sussex Close is actually in Somerset Drive.

Or the case - like Croft Close - where the street is a loop, with odds [or evens] on the outside of the loop and evens [or odds] the roundabout-like inner side.

But I'm still at a loss to explain the convention found in Barley Farm Road - it's a Y, with the 2 arms joining up with Berkshire Drive, and the foot forming a junction with barley Lane. WHY?

Here all the roads you see are Barley Farm Road.