I want to know if the connection to a roundabout with the roads is correct as shown in the image (http://imageshack.us/photo/my-images/541/catturacxw.jpg/).
In my opinion, it is wrong to connect the streets with a connection for each direction of travel.
I think it’s more accurate this (http://imageshack.us/photo/my-images/541/cattura1x.jpg/).
In this second way, we avoid considering each link as exit from the roundabout.
I would like to know which of the two ways is correct.
Both ways of mapping are more or less correct.
General rule is: when there is a clear separation between two roads they may be mapped as 2 highways.
Some mappers believe that already a solid line between 2 lanes is a big enough separation.
Most routers are able to count the correct number of exits because they look on the “oneway”.
Thanks for your reply.
A problem in designing two accesses is that the navigator, before saying “take the roundabout”, said to make a turn to the right that does not exist.
In the first picture (http://imageshack.us/photo/my-images/54 … racxw.jpg/) regarding the connecting road from the west, both oneways are pointing wrongly. They should both be reversed. In my opinion this is the correct way to show the roads connecting to the roundabout as this is what is on the ground. With the oneways corrected the routing may well be resolved.
Your second image does not show the roads mapped as they are on the ground.
“A problem in designing two accesses is that the navigator, before saying “take the roundabout”, said to make a turn to the right that does not exist.”
It seems to me the best solution would be to label the two accesses as “roundabout_link” (I just invented that name, it could be something else), and the navigator, if it sees the sequence (normal road)->roundabout_link->roundabout, should not tell you about the first transition. (And similarly when you exit the roundabout)
I am sure in this particular case the fact that two of the link sections to the roundabout had the oneways incorrectly marked (reversed on the road going west), was definitely a contributing factor to the incorrect routing. If the oneway direction of the link roads is wrong, (what ever they are called) only incorrect routing could be expected.
As nothing more has been said by PaRi53 I have corrected the oneways, hopefully now all will be well.