Add a POI in pgrouting

Question

I am new of pgrouting.

I have created a new network using osm2po with both edges and nodes. Everything works fine, and I have tested the system using the Pgrouting Layer plugin for QGIS but I have noted that I am not able to use a table of POI that are not intersecting my network.

I am not able to figure out how to add these POI as nodes, is there any easy way to solve this? I have already checked the workshop manuals and other discussions, but it seems to me that they don't explain how to do this operation, or, better, I understand that the POI should be on the edge in oder to split the lines before to create the table with the nodes, but if I have a table with hundreds of POI (e.g. all the bar/pubs in a city), and all these points are not in the edge, is there a way to fix it automatically?

Using QGIS 2.99 I see that there are some interesting tools for network analysis, if I try the shortest path algoritm using my table of POI I have this result

I would like to reach the same result using Pgrouting.

Is it possible?

Answer 1

You could use the ST_Closespoint function in PostGIS on your POIs before generating the network.

Here is a similar question: How to connect points (bus stops), which don't lie on the lines (LINESTRING), to a network?

Answer 2

You could use one of the withPoints function to start routing from a POI. The withPoints functions are not officially released yet, but they will be in the next release probably.

See this summary page about the concept with some network diagrams: http://docs.pgrouting.org/2.4/en/withPoints-family.html#withpoints

The with points family of function give you the ability to route between arbitrary points located outside the original graph.