Traffic Island query

[tompatt]

Wonder if you can help. Having entered a roundabout, lets say for example where the A5 meets the A43 at Towcester, which of the 2 roads are you using?

Would be based on "seniority" so the A5 takes precedence and the A43 takes a short multiplex or is there denomination?

[Bryn666]

It entirely depends on which route is considered more important; but there is no hard and fast rule and signage can be a total disaster area where multiplexed routes are concerned.

[danfw194]

The example you mention is an interesting one, because the A43 is the more important route through that roundabout.

[Truvelo]

The speed limit used to be one way of telling what is the more important road. However these days it tends to be the lowest common denominator

[ellandback]

OS mapping suggests a green road trumps a red road (the roundabout being coloured green), a red (or green) road trumps an orange road, and so on. That doesn't help with your A5/A43 example where both roads are primary.

My personal take on this, which may or may not have any bearing in law or mapping, is that the answer is "either", and it depends on context. If I was travelling from the A5 to the A5, I wouldn't consider that I had ever left the A5. If I was travelling from the A43 to the A43, I wouldn't consider that I had ever left the A43. (And if I was travelling from one to the other I would consider the change had taken place when I left the roundabout and unambiguously joined the 'new' road for the first time).

Obviously this requires me to accept at least one quadrant of the roundabout as being both A5 and A43 depending on context, but I think that's consistent with Bryn's observation that there is no hard and fast rule.