maps_directions transit mode returns "No route found" in Japan

[eliottness]

Bug Report

What happened

I was trying to plan a trip to Ghibli Park in Nagoya using the maps_directions tool with mode: transit, and kept getting a No route found error — even for well-connected routes like Nagoya Station → Ghibli Park.

What's odd is that switching to mode: driving works perfectly fine for the same origin/destination. And transit directions work without issue in other countries — I tested Paris → Lyon and it returned correct step-by-step train instructions in French, including the train leg and walking segments.

Steps to reproduce

{
  "tool": "maps_directions",
  "origin": "Tokyo Station",
  "destination": "Nagoya Station",
  "mode": "transit"
}

Returns:

No route found from "Tokyo Station" to "Nagoya Station" with mode: transit

Same call with "mode": "driving" works fine and returns the full route via the Tomei expressway.

Root cause (after investigating)

After digging into this, it looks like the issue is on Google's side: the Routes API (which this server uses under the hood) has incomplete transit coverage for Japan. The legacy Directions API has historically supported Japanese transit, but the Routes API seemingly doesn't — at least not yet. Google's documentation just says "functionality varies by region" without any specifics, so there's no clear timeline on when (or whether) Japan will be supported.

Suggested fix

A couple of options worth considering:

1. Fall back to the legacy Directions API for transit requests when the Routes API returns no results — the legacy API endpoint is https://maps.googleapis.com/maps/api/directions/json and it accepts the same mode=transit parameter.
2. Surface a clearer error message when transit mode fails in unsupported regions, pointing users toward the limitation rather than a generic "No route found".

For what it's worth, Japanese users are a likely audience for this MCP server given the Google Maps integration — routing to places like Ghibli Park, Kyoto stations, etc. would be a very common use case.

Environment

• MCP server: mcp-google-map (latest)
• API: Google Maps Routes API
• Affected mode: transit
• Affected region: Japan (confirmed working in France)

Thanks for the great project — the other tools like maps_explore_area, maps_compare_places and maps_search_along_route work really well!

[cablate]

Thank you for using this, and very appreciate you taking the time to report the issue and share your suggestions!

We’ll review the proposed fix and aim to have an update ready within two days.

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