Feature Request: Built-in Fallback Reverse Geocoding Support

Hi team,

I’m currently working with the latest Traccar version and ran into a limitation with reverse geocoding.

At the moment, Traccar allows only one geocoder provider at a time (e.g., LocationIQ, MapTiler, Nominatim, etc.).
But in production environments, providers may fail due to network errors, API downtime, or quota limits.

Why Fallback Matters

If a provider goes down or hits a quota, address resolution stops completely.
Example error I encountered:

WARN: Geocoder network error - us1.locationiq.com - UnknownHostException

This means my system could not resolve addresses at all until the provider came back online.

Proposed Solution

Introduce fallback geocoding where:

1. The primary geocoder is tried first (e.g., LocationIQ).
2. If it fails or returns empty, a secondary geocoder (e.g., MapTiler, Nominatim) is used automatically.

Example XML config

<entry key='geocoder.enable'>true</entry>
<entry key='geocoder.type'>fallback</entry>
<entry key='geocoder.primary'>locationiq</entry>
<entry key='geocoder.secondary'>maptiler</entry>
<entry key='geocoder.cache'>true</entry>
<entry key='geocoder.cacheSize'>20000</entry>

My Attempt

I tried building a custom FallbackGeocoder.java that checks if the primary fails, then calls a secondary.
It works in principle, but since "fallback" isn’t a built-in type in the current DI setup, I had to patch Traccar code manually to register it.

Here’s a simplified snippet from my experiment:

public class FallbackGeocoder implements Geocoder {
    private final Geocoder primary;
    private final Geocoder secondary;

    public FallbackGeocoder(Config config, Client client) {
        this.primary = new LocationIqGeocoder(...);
        this.secondary = new MapTilerGeocoder(...);
    }

    @Override
    public String getAddress(double lat, double lon, ReverseGeocoderCallback callback) {
        String address = primary.getAddress(lat, lon, callback);
        return (address == null || address.isEmpty())
            ? secondary.getAddress(lat, lon, callback)
            : address;
    }
}

Request

Would it be possible to add native support for fallback reverse geocoding in Traccar?

This would make deployments much more robust.
Even a simple config allowing primary + secondary providers would cover most real-world needs.

Thanks for considering this improvement!

I would recommend just using a script on your end to route to different providers depending on availability. It doesn't make sense to add more complexity to Traccar itself.

Noted with thanks Anton, so you mean i should have a custom endpoint api that does the switching between geocoding providers?

Yes.

Noted thanks