Hi,
yes, they need some tags that mark them as passable. I double-checked the code for the car encoder again. Taking both AbstractFlagEncoder.java#L206 and
CarFlagEncoder.java#L67 into account, one or more of the keys
"motorcar", "motor_vehicle", "vehicle", "access"
with values
"yes", "permissive"
would add the roads to routing.
So, e.g., if these roads are “regular” roads with gates that can be accessed by any vehicle, I’d assume that “vehicle=yes” would be appropriate (see Key:access).
Regard,
Jan