if I understand correctly the new overtaking conditions only apply to roads that are flagged as 'one-way'; regular two way roads continue to use the old overtaking rules. If that's the case it's not going to be possible to test the patch with any of the standard pak sets as they contain no 'one way' roads since all legacy roads are by default two way. Am I correct?
Yes. You are all correct
Also the citycars certainly needs to know about the new conditions too.
Writing conditions for citycars is just now in progress. This takes some time because the routing algorithm of citycars is quite different from that of road vehicles. In next release, this patch will work correctly with citycars!
Perhaps you could share, for testing purposes, a pak file for a road with the flag set to 'one way'? I think more people would be prepared to test the patch if there was a ready made add-on to help them do that.
I can do a wayobj integration, but in that case please stop adding features. Patching and testing needs some time.
To answer to these comments, I have to introduce SIS road project.
SIS, which means Systematic Infrastructure Standard, road project is a project which brings more realistic roads to reproduce various scenes in simutrans. The original aim of this patch is to reproduce highway system using SIS road addons, and that is still same now. I modified the dat files of SIS road addons and am using for testing. So, I want to share the modified SIS road for testing purpose but that needs a permission by the copyright holders. I'm contacting them but it takes some time to distribute. If you know road addons that is suitable for one-way road and that can be re-distributed, please tell me. I'll modify the dat file and share with you.
This project has very strong connection with SIS road project. I once thought that wayobj should have "overtaking_info" flag. However, wayobj is used as sidewalls. Please take a look at 1.jpg and 2.jpg. These are wayobj. If wayobj had overtaking_info flag, we would have to cut sidewalls at the point where the overtaking rule changes. Wayobj is wayobj, should not be used as a marker of overtaking conditions. A new object like wayobj but specified to overtaking_info flag should be provided to realize flexibility of conditions and avoid re-paking way objects. However, this would be a huge work so I'll think about this again after I finish writing conditions for citycars.
SIS road project can be seen from http://seesaawiki.jp/sis_simutrans/d/SIS%20Road
, but they are all in Japanese. You can download various addons from this page.