The road models themselves have the pathway incorporated into them, its called the Roadway LOD.
Joining the road pieces together then creates a longer pathway ... etc.
Airfield ILS data is just a collection of waypoint co-ordinates specific to the current map of course
ilsPosition, ilsDirection, ilsTaxiIn and ilsTaxiOff.
ilsPosition: This is the point on one end of a runway that the aircraft aims for when landing. (X,Y)
ilsPosition[]={9765,9951}; ... for example.
ilsDirection: This is the direction your runway runs in for landing, together with the glideslope value (X,Z,Y)
For example if you are landing from the south, heading north (0), you then take the opposite compass bearing (180) and the first number is the sin of this value (sin180).
The second number is the sin of the desired glideslope value, standard value for OFP was 0.080 (about 4.6 degrees).
The last number is the cos of the compass bearing used in the first number (cos180).
ilsTaxiIn and ilsTaxiOff: These are waypoint coordinate pairs held in an array, they define the points for the plane to head for when taxiing after landing (ilsTaxiOff) and for take off (ilsTaxiIn).
The first number pair for ilsTaxiOff is usually the same as ilsPosition.
Planck