NOTES FOR MERGERS:
SD: please double-check names for misspellings, and note Mc/Mac names aren't capitalised. I haven't automatically changed them. You'll need to double-check against another source, as sometimes Mc/Mac names genuinely aren't capitalised.
SD: while motorways, tracks, footways and residential streets (except that many CBD streets are classed as 'residential') are generally accurate, the use of primary, secondary, tertiary and trunk are a bit hit and miss. How things are generally used in NZ OSM:
motorway: roads that are legal motorways
trunk: expressways, and single-digit state highways
(maybe we should classify them using the NZTA's definition of importance: http://www.nzta.govt.nz/planning/process/state-highway.html#planning - it counts some two-digit highways as the highest level and some one-digit highways as the lowest level)
primary: all other state highways and major multi-lane arterials, like Waterloo Quay in Wellington. In Auckland this covers the 'Urban Routes': those with numbers - like Pah Road/Manukau Road/Gillies Ave which is 'Urban Route 12'.
secondary: other urban arterials - anything that runs through several suburbs - like Ponsonby Road or Mount Eden Road in Auckland, or Adelaide Road in Wellington, and many rural roads
tertiary: urban distributors - generally only run for a short distance. If it has traffic lights, it should be at least a tertiary road
residential: really minor streets. If it doesn't have a centreline, or ends at a give way or stop sign where it meets the main road, it's probably one of these
NOTES FOR TAGGERS:
SD: highway data from NZOpenGPS added 2/10/12
SD: note that the 'speed' doesn't correspond to the speed limit or ordinary speed, it's just for relative weighting for routing purposes.
SD: the highway types come from mp2osm_linz_jr_pl.py, which you can find in the contrib/ directory in source.
SD: need to check that junctions and oneway roads have correct direction (i.e. way goes in direction of traffic).