Voice navigation and double roundabouts.

This topic was brought up by me in the thread about mini roundabouts, I figured it was best best to start a new thread so I could explain the problem I see in detail with a couple of examples, There should be 2 examples to follow (if the image upload works)…

Firstly, here is an example of 2 roundabouts where the lane you are in at the first roundabout to go straight across it depends upon whether you intend to go straight on or right at the second roundabout. I’ve highlighted the routes with green for straight on, an purple for turning right. In this example (which is heading eastbound) after heading straight over the first roundabout there is time to change lanes before the second roundabout and get into the correct lane.

Coordinates: 51.679110,-4.133066

[Mike Archer]

Ok, the image upload failed, here’s url for the image…

http://www.zen73904.zen.co.uk/2017-08-03%20234023.PNG

• This reply was modified 6 years, 8 months ago by Mike Archer.
• This reply was modified 6 years, 8 months ago by Mike Archer.

Secondly, here’s a second situation with a double mini roundabout with the same situation, likewise here there are 2 lanes to go straight across the first roundabout and you need to be in the correct lane on the second roundabout depending if you are going straight on or turning right. Again I’ve highlighted the routes with green for straight on, and purple for turning right (in this example heading westbound). There is no opportunity to correct your lane here and you must choose the correct lane to go straight across the first roundabout dependent on your intention at the second one.

http://www.zen73904.zen.co.uk/2017-08-03%20234112.PNG
Coordinates: 50.341728,-5.111189

I’m sure there are many other double mini roundabouts with similar quirks, and that I why I said it would be difficult for voice navigation to guide you across them.

I totally agree with Mike’s comments about being in the correct lane to safely complete your navigation of the roundabouts.

If I can throw another Cornish double roundabout into the mix this seems to have even more issues than the examples you gave. The roundabouts are in St Austell and are on the main route to The Lost Gardens of Heligan (via Pentewan Road B3273) so will be used by many people unfamiliar with the area. Coordinates are 50.3345578280603,-4.793913523573934

I assume from looking at Edit that HERE consider a roundabout to be multiple sections of road linked together rather than a single physical entity?

Trevanion Road A390 approaching the roundabout becomes 3 lanes from a single lane. Going away from the roundabout it is 1 lane but shown as 2-3 lanes on HERE. I assume that in Edit the road would need to be split to show the correct number of lanes in each direction?

The roundabout that Trevanion Road enters is shown as 1 lane on HERE – how can a 2-3 lane road become a 1 lane road? The road should become a 1 lane road before the junction? Surely, HERE’s basic system validation should at least raise this as a concern if not prevent it from happening?

Pentewan Road and South Street also become 3 lanes when joining their respective roundabouts with 1 lane leaving the roundabout but are shown as 1 lane in each direction on HERE. Penwinnick Road becomes 2 lanes when joining the roundabout with 1 lane leaving the roundabout but is shown as 2-3 lanes in each direction. The sections of road that make up both roundabouts are all shown as single carriageway road. The section of the A390 linking the 2 roundabouts is correctly split and shown as 2-3 lanes in each direction.

Does HERE have any plans to allow different numbers of lanes on opposite sides of a single section of road as with different speed limits? The exact number of lanes would need to be specified with a facility to link lanes to the destination road (and lane?) as Mike has done in his examples with the coloured lines.