# [pgrouting-users] Oneway problem

Espen Isaksen espen.isaksen at gmail.com
Fri Oct 15 08:23:16 EDT 2010

```But I think I have understood this correctly then. That is why I did this:

update elveg set cost=length+1000000 where oneway='FT' ;
update elveg set reverse_cost=length+1000000 where oneway='TF'

This should do exactly what you explained.

However, I wonder if this should concern me?
http://pgrouting.postlbs.org/ticket/212

Espen

On Fri, Oct 15, 2010 at 2:08 PM, Ralf Suhr <Ralf.Suhr at itc-halle.de> wrote:
> Hi Espen,
>
> one edge is defined by to nodes in pgrouting.
> You need to match the definition of oneway street to the edge.
>
> If the direction of edge and oneway street are the same, then only the
> reverse_cost must be higher. In case direction from edge are opposite to
> oneway street, the reverse_cost become the the cost for driving the oneway
> street.
>
> Gr
> Ralf
>
> Am Freitag 15 Oktober 2010 13:34:47 schrieb Espen Isaksen:
>> Hi!
>>
>> I have a feeling there is something I do not understand concerning
>> routing with oneway streets, but after hours of testing and googling I
>> have to ask you guys on this list.
>>
>> I have a street network for Norway in my database and I have added the
>> columns cost and reverse_cost. I have initially set both columns to
>> the value of the length of the geometry.
>>
>> Then I updated cost and reverse cost by this:
>>
>> update elveg set cost=length+1000000 where oneway='FT' ;
>> update elveg set reverse_cost=length+1000000 where oneway='TF' ;
>>
>> I have this sql running shooting star. The sql is from the FOSS4G workshop:
>>
>> SELECT rt.gid, ST_AsGeoJSON(rt.the_geom) AS geojson,
>> length(rt.the_geom) AS length, elveg.gid
>> FROM elveg,
>> (SELECT gid, the_geom
>> FROM shootingstar_sp(
>>                         'elveg',
>>                         157334,
>>                         157165,
>>                         10000, 'cost', true, true)
>>                      ) as rt
>> WHERE elveg.gid=rt.gid
>>
>>
>> What happens is that if I set the cost column high, the route will not
>> travel on this road in both directions. And whatever I set
>> reverse_cost, there is no changes to the route.
>>
>> Do I need to explain pgrouting to use the reverse_cost column? And why
>> is the cost column working both directions?
>>
>> Espen
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>>
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```