Routing for Japan: for under 125cc motorcycles

[serika12345]

In Japan, the roads you can drive on depend on your vehicle's engine displacement. I'd like to implement routing logic specifically for Japan, but is it permitted within this project to implement features that reflect country-specific conditions like this?

[biodranik]

Are these rules specific to Japan only or to some other countries too? What are the specific OpenStreetMap.org tags related to it?

[serika12345]

Thanks. I checked the OSM tagging docs and the Japanese OSM community guideline.

The exact rule I am referring to is: in Japan, motorcycles up to 125cc are not allowed on expressways / motor-vehicle-only roads, while motorcycles over 125cc are allowed.

This should probably not be implemented as a hardcoded “Japan-only motorcycle” rule. The relevant OSM access tags are:

• motorcycle=*: larger motorcycles / 自二輪
• moped=*: small motorcycles excluding 50cc mopeds / 小二輪（原付を除く）
• mofa=*: 50cc mopeds / 原付

So, for a “<=125cc motorcycle” route profile in Japan, the router should avoid ways tagged moped=no and mofa=no. For Japanese expressways / motor-vehicle-only roads mapped as highway=motorway / motorway_link, moped and mofa should also be treated as not allowed by default.

For signs that ban all motorized two-wheelers, the related tags would be motorcycle=no, moped=no, and mofa=no.

The general idea is not Japan-only: OSM has global moped=* and mofa=* access tags, and some other countries also have displacement-based restrictions. But the exact <=125cc mapping above comes from the Japanese OSM tagging guideline.

[biodranik]

So how can it be generalized as, e.g., a simple "avoid" setting that takes into account different tagging/laws in different countries?

[biodranik]

And what will be the difference from the current "avoid highways" option in Japan?

[serika12345]

The difference from the current "avoid highways" option is that this is not just a preference to avoid highway=motorway.

From the Organic Maps code, the current Motorway avoid option seems to be classified only from highway=motorway. That can cover many Japanese expressways / motor roads if they are mapped according to the Japan tagging guideline, because Japan tagging says expressways or motor roads with the blue car sign should be tagged as highway=motorway.

But the small-motorcycle case is a legal access restriction, not just an avoid preference. A <=125cc route should also respect explicit access tags such as:

• moped=no
• mofa=no
• possibly motorroad=yes / country-specific motorroad implications where applicable

So the generalized feature could be a small motorcycle / moped access profile, or an "avoid roads prohibited for mopeds/small motorcycles" option. It should use OSM access tags and country-specific defaults, instead of only avoiding highway=motorway.

For Japan specifically:

• avoid/disallow highway=motorway and motorway_link for moped / mofa
• disallow any way explicitly tagged moped=no or mofa=no
• keep motorcycle=* for larger motorcycles, because >125cc motorcycles are allowed on those roads