I’ve been using osm2po to load osm data into the database. osm2po creates a to_cost and a reverse_cost value for each way. I recently switched to osm2pgrouting so I could use the generated “classes” table to give more weight to roads like highways in my driving directions. However, the ways table that osm2pgrouting generates has a to_cost column, but all the values in it are null. For kicks, I tried using the reverse_cost as the to_cost and it seems to work, but I wanted to ask about this… is that normal? Am I supposed to generate the to_costs some other way?
On 12/22/2011 9:28 AM, John Williams wrote:
I've been using osm2po to load osm data into the database. osm2po
creates a to_cost and a reverse_cost value for each way. I recently
switched to osm2pgrouting so I could use the generated "classes" table
to give more weight to roads like highways in my driving directions.
However, the ways table that osm2pgrouting generates has a to_cost
column, but all the values in it are null. For kicks, I tried using the
reverse_cost as the to_cost and it seems to work, but I wanted to ask
about this... is that normal? Am I supposed to generate the to_costs
some other way?
The to_cost is only used when a rule is also present and you are using shooting_star. rules are for turn restrictions and if the path follows the rule then the to_cost should get added to the path cost.
Until OSM has better support for turn restrictions, it is unlikely that these columns will be populated.
Also FYI, shooting_star in version 1.05 has problem and I do not recommend using it until they are fixed or that you validate that it is working for the cases you are giving it. I think 1.02 was the last working version. It is on our priority list to get fixed, but at the moment we do not have an active developer that can look into it.
-Steve W