Question about railtypes

[zooks]

I'm trying to write an extension to the metro track set.
Basically, adding different types of catenary covers (e.g. roads and parks). Now when I define an additional railtype like below, no trains are able to run on it.
Ideally, I want all trains to run on this track (or at least the same selection that runs on the other metro tracks in this set), from all trainsets (or, the dutch trainset would be a good start)

What do I have to list in compatible_railtype_list, powered_railtype_list, and alternative_railtype_list to make this work?

Code: Select all

if (railtype_available("MTR1") || (loading_stage == LOADING_STAGE_RESERVE)) {
        //count number of activated railtypes
        param_railtype_activated = param_railtype_activated + 1;
        item (FEAT_RAILTYPES, item_metroroad) {
            property {
                label:                          "MTR1";
                name:                           string(str_metroroadtrack_name);
                menu_text:                      string(str_metroroadtrack_menu_text);
                build_window_caption:           string(str_metroroadtrack_build_window_caption);
                autoreplace_text:               string(str_metroroadtrack_autoreplace_text);
                new_engine_text:                string(str_metroroadtrack_new_engine_text);
                introduction_date:              date(1700,1,1);
                compatible_railtype_list:       [];
                powered_railtype_list:          [];
                railtype_flags:                 bitmask(RAILTYPE_FLAG_CATENARY, RAILTYPE_FLAG_NO_LEVEL_CROSSING);
                curve_speed_multiplier:         1;
                station_graphics:               RAILTYPE_STATION_NORMAL;
                speed_limit:                    0;
                acceleration_model:             ACC_MODEL_RAIL;
            }
            
            //OpenTTD 1.2 23758
            if (openttd_version >= version_openttd(1, 2, 0, 23758)) {
                property {
                    toolbar_caption:            string(str_metroroadtrack_toolbar_caption);
                    maintenance_cost:           24;
                    alternative_railtype_list:  [];
                }
            }
            ...