To fetch the roads I use overpass turbo API. They are sometimes slow and timeout and sometimes limit amount of requests that we can send. So I found three endpoints of overpass turbo and rotate between them: in case when one fails I go to the next one. If none was able to handle the request, I bail out and show the error.
That said, I also cached 3,000 cities with population over 100k citizens and try the cache first, before going to overpass. That may be the reason why it is fast in some cases and slow in others.
By the way if someone has more stable/fast overpass endpoints - I will be happy to add them to the list!
Now the site is not loading at all for me. Oops, there it goes. I think it could be overwhelmed.
I think it just does not have data on smaller towns and cities. I've tried several US smaller cities and nothing works. However, your link does. I can get San Diego and Irvine, CA. But I can't get Redlands or Yucaipa, CA. I can't get Polson, MT (nor Kalispell nor Helena).
Edit: Update - Finally got some data on Polson, MT.
Sorry it takes so long sometimes! I assume overpass (the back end that gives data) may experience higher loads which would affect response time! But glad it finally worked!
That said, I also cached 3,000 cities with population over 100k citizens and try the cache first, before going to overpass. That may be the reason why it is fast in some cases and slow in others.
By the way if someone has more stable/fast overpass endpoints - I will be happy to add them to the list!