[pgrouting-users] Algorithym Use in pgRouting

On 7/9/2013 7:23 AM, Muhammad Iqnaul Haq wrote:

Hello Mr. Woodbridge

It's me iqnaul who asked about using pgrouting to build an application
avoiding any traffic disturbances. My supervisor asked me to build the
application to avoid any traffic disturbances (e.g road blocked, traffic
jam, road construction) so that disturbances will defined as a barrier.
Can you suggest me the suitable algorithym (pgrouting function) that
match my requirements? Because I found the pgrouting 2.0 now support
more functions.

Glad to hear your opinion and suggestion

best regards


Hello Ignaul,

My general preference for routing is to use the trsp algorithm even if I do not have turn restrictions. The astar algorithm is also a good one to use.

The trick to using any of these algorithms to deal with traffic issues or road blockages is the following:

If you have historical average traffic speed or access to traffic speed senors, then I would set up something like:

1. edge_table with topology, default costs, etc

2. average_speed table that would be include gid, start_time, end_time, avg_spd, this can be joined to the edge table to get the average speed for any given time window.

3. avoidance_table that contains lines and/or polygons for that represent areas that traffic can not cross

Then when you select your edges for the solution, you join that with the traffic table and exclude any edges the intersect the avoidances.

If you want some consulting help to set up a system like this please contact me off list. I have done this for other clients and it works very well when you have access to the data and a road network for your area of interest.

Best regards,