bridge is a property and no highway-type in OSM.
So let's assume it has been tagged along a secondary street.
There are two approaches in osm2po:
- Give it an own road clazz, but then you'll lose the highway type.
- Leave it as is, and mark its existence in the flags
For both variants it is recommended to extend the flaglist:
wtr.flagList = car, bike, foot, rail, ferry, poly, bridge
For the first approach you'll need something like this:
wtr.tag.bridge = 1, 66, 50, bridge
wtr.tag.highway.secondary = 2, 21, 60, car
wtr.allow.highway.secondary = car
wtr.finalMask = car
Pay attention to the secondary street's priority of 2 (first param).
This means, that if both are tagged, the bridge will win and you'll receive a clazz of 66.
Nevertheless, the second approach is recommended:
wtr.allow.bridge = bridge which does not change the clazz.
Instead you'll find the hint in the table-column flags.
The flags are Int32-Bits, thus a combination of
car|bridge is a simple IntValue, resulting from
1 + 64 = 65