[OSM-talk] Non-junctioning crossing roads

[David Groom]

> ----- Original Message ----- 
> From: David Groom
> To: Steve Bennett ; Open Street Map mailing list
> Sent: Tuesday, December 01, 2009 1:33 PM
> Subject: Re: [OSM-talk] Non-junctioning crossing roads
>
>
> Yes there should be a node at the crossing.
>
> Most of those ways are one way , so routing software would not allow many 
> turns anyway.  The only turn I could see being currently as valid would be 
> when going south on Lakeside Drive and turning right onto the northbound 
> carriageway.  To stop this you need a turn restriction relation.

Oops.  I could see a valid turn from the northbound carriage way left onto 
lakeside drive, so you would need a no_left turn restriction to stop that.

Alternatively the whole junction restriction could be accomplished as konrad 
said by a couple of only_straight_on restrictions

David


>
> http://wiki.openstreetmap.org/wiki/Relation:restriction
>
> Basically with Lakeside drive having role "From", the junction node having 
> a role "via", and the Northbound carriage way having a role "to"
>
> David
>
>
>
> ----- Original Message ----- 
> From: Steve Bennett
> To: Open Street Map mailing list
> Sent: Tuesday, December 01, 2009 1:14 PM
> Subject: [OSM-talk] Non-junctioning crossing roads
>
>
> Hi all,
>  Is it ever correct for two roads to cross physically, at the same level, 
> but not create a junction between them?
>
> The situation I have looks like:
>
>                  C
>         |
> A-->-----+----->--B
>         |
>         v
>         |
>         D
>
> With apologies for ASCII art. Cars go from A to B, or from C to D, but 
> they can't turn. It's controlled by traffic lights. So, do I create the 
> junction represented by the +, or just let them cross over? If I create 
> the junction, how do I stop routing software trying to make turns?
>
> It's here if want to see it (Nearmap imagery):
> http://www.openstreetmap.org/edit?lat=-37.85348&lon=144.979389&zoom=20
>
> Queens Rd southbound branches to become Lakeside Drive, crosses Queens Rd 
> Northbound.
>
> Sorry for the noob question, just wanted to make sure I get this right.
>
> Steve
>