Investigate `vds_config.xml`

[ian-r-rose]

In the PeMS Clearinghouse feed there is regularly updated file vds_config.xml. It contains a snapshot of the VDS metadata for the present day. There are a few questions we have about this file:

1. Does it contain any information that is not in the STATION_STATUS or STATION_META files? @kengodleskidot indicated that he saw some information about the controller to station mapping, though I was unable to find that. @kengodleskidot do you have any more information there?
2. If there is information that is not in the above tables, how would we want to ingest and parse it?

[kengodleskidot]

The vds_config.xml file contains the following data and associated relationships that we will need to capture for table, reporting and visualization development:

• Which counties and cities are associated with a specific district with identifying ID's
• Freeway crossings located along routes for each district

State, City, County and District data are contained in tables that @pingpingxiu-DOT-ca-gov is migrating over in the CITIES, COUNTIES, DISTRICTS, STATES tables. The freeway crossings are located in the FWY_CROSSINGS table that is also being migrated over. I was mistaken about the controller to station association as this is located in each district configuration file, not the vds_config.xml. Apologies for any confusion.

[ian-r-rose]

Which counties and cities are associated with a specific district with identifying ID's

Correct me if I'm wrong, but I think counties, cities, and district are already in the STATION_META table. I'm unsure about the freeway crossing information. Is this inferrable from the state_pm and abs_pm data?

[kengodleskidot]

You are correct that cities, counties and districts are in the metadata by VDS (station). Unfortunately, the freeway crossing information is not, particularly the crossing information in District 1, 2 and 9 where we are getting no VDS data. PeMS generates reports at three geographical levels: the individual detector level (at a point along a freeway corridor), the spatial level (a freeway segment), and the geographical aggregate level (multiple freeways within a larger geographical area, such as a city, county, Caltrans District, or all of California). Do you think we can accomplish this using the STATION_META table only or would seed files/tables be beneficial for geographical aggregations?

[ian-r-rose]

Are crossing information available in the XML district configuration files that you've seen? Basically, I'm trying to understand whether we need to ingest vds_config.xml, or whether we can grab the same data from earlier in the process.

Do you think we can accomplish this using the STATION_META table only or would seed files/tables be beneficial for geographical aggregations?

I think we can at least do it at the city, county, district, freeway, or state level. The one that I don't see a way to do right now is freeway segment, which doesn't seem to be in any of the metadata files I've seen (including vds_config.xml). For freeway segments, we may need to bring in seed files, unless that's also available in the XML configuration files from the districts.

[kengodleskidot]

I am not seeing crossing information in the XML district configuration files but, if needed, we can get this from the FWY_CROSSINGS table that Pingping will be bringing over. We can tackle how and where we get the freeway crossing data and it's use at a later time. Fow now I think we can dismiss the ingestion of the vds_config.xml file since the data is available in other ways. I believe we can close this issue out unless you have any other questions @ian-r-rose.

[ian-r-rose]

Thanks for the discussion @kengodleskidot! I'll go ahead and close this, but if we decide that we do need something from the vds_config.xml file, we can always reopen.