First of all, I would like to offer a suggestion on towards road type definitions:

Streets: In town streets that are not primary routes with typical speeds of 30 Mph (50 Kph) or less
Primary Street: Well traveled route with speeds typically between 30-45 Mph (50-75 Kph)
Minor Highway: Any paved highway with typical speeds of 50-60 Mph (80-95 Kph)
Major Highway: Typically 2-lane (one for each direction) Highways that are major routes covering multiple counties or states. Typical speeds of 55-65 Mph (90-105 Kph)
Freeway: Typically 4 or more lanes of traffic and often has exits and entrances with typical speeds over 60 Mph (95 Kph)
Dirt Roads: I wish the 4x4 trails were not part of this because I think dirt road and 4x4 trails differently ... I don't imagine a car going to drive on an actual 4x4 trail ... I do believe unless we add an alleyway option, we should choose dirt road for all alleyways
Service Road: This is obvious that a service road is a road that is not to be driven by the public. I would like to see the map automatically give no access to these roads and not suggest these roads as a spot to turn around.
Parking Lot Road: Main roads around a parking lot. I would say the the entrance and exit of a parking lot and the perimeter and the best paths to get to the front doors with the remainder of the lot filled in as the parking lot landmark. I say this because I often see Waze created alerts reporting the unbalance of the GPS data and the map based road information if it is not defined as a parking lot
Private Road: I believe the private roads should automatically be considered 2 way and not be able to turn into. I also they should not be as noticeably on the map. It should be as noticeable as a dirt road. I also don't believe it should wait for wazers to drive these paths to become the less distinctive road pattern (currently shows as munchable roads but since they are private roads, I can't munch them because they are private roads sometimes even blocked by a gate.