[mapserver-users] Show traffic on roads.

[Mohit Sindhwani]

On 2020-2-26 8:48 am, Erik H wrote:
> Depends on your requirements. If you just want to visualize typical 
> traffic conditions, MapServer can do the job, it's pretty 
> straightforward. Just join your road geometries with the congestion 
> data (actual speed / free-flow speed), apply some filters (SQL 
> conditions) on road class and maybe congestion (omitting non-congested 
> roads), and render that in the appropriate color.
>
> If, on the other hand, you have a feed with speeds that vary 
> frequently, it gets tricky because you can't really use a regular tile 
> cache. I ended up abandoning MapServer for this - the problem was not 
> so much the rendering, but PostGIS was getting overwhelmed. If you get 
> your speed data from a company like HERE or INRIX, you should be able 
> to use their tilers. If not, you have a nice challenge.

How is the data created and stored? How large is the area? We do a bunch 
of things as a traffic services company, and have found that different 
things work better for different scenarios. MapServer and GeoServer have 
both worked for us in the past. The challenge is always on how pretty 
you want it to be, how much compute you're willing to spend, how often 
the data updates, etc.

It's correct that the regular tile cache doesn't expire data in the best 
way to support this :)

Best Regards,
Mohit.
2020-2-27 | 1:44 pm.