Looking for a nudge in the right direction here.

What I need to do is find the "centroid" of my road network. I actually want to find two different points. One (equidistant), if you started at this point and drove x miles in any direction you would be at the end of the road network. And two (equitemporal), if you started at this point and drove x minutes in any direction you would be at the end of the road network.

Thanks in advance.

What I need to do is find the "centroid" of my road network. I actually want to find two different points. One (equidistant), if you started at this point and drove x miles in any direction you would be at the end of the road network. And two (equitemporal), if you started at this point and drove x minutes in any direction you would be at the end of the road network.

Thanks in advance.

Of course, this methodology will only provide you with the junction which has the smallest eccentricity. If you are looking for a more general position along the graph (e.g., potentially somewhere along an edge), then the process would be more complicated.

Also, this method will not scale very well for very large graphs (with more than approximately 5000 junctions), due primarily to memory limitations for solving such large OD instances. How big is the network you are planning on computing this value for (in terms of the number of junctions and edges)?