Option 1:
Define road/tramtype using different "allocate label" properties.
0x07: Allocate road label
0x08: Allocate tram label

RoadTypeReserveInfo:
 case 0x07: GetRoadTypeByLabel(rtl, ROADTYPE_ROAD, false);
            rt = AllocateRoadType(rtl, ROADTYPE_ROAD);
 case 0x08: GetRoadTypeByLabel(rtl, ROADTYPE_TRAM, false);
            rt = AllocateRoadType(rtl, ROADTYPE_TRAM);


Option 2:
Flag in property 0x10.

RoadTypeReserveInfo:
Labels are not immediately allocated, but only collected per GRF:
RoadTypeReserveInfo also collects the road/tram flag.

After the reservation pass, stuff are really allocated.

Problem: This breaks GRF loading stages, and essentially adds a second reservation stage. GRFs cannot properly test for already defined labels.


Option 3:
Separate GRF features, both with property 8

Advantage: (GRF feature, ID) is a key to the type, as it is to all other thing like industries.


=> Option 3 > Option 1 > Option 2