OpenStreetMap

ROAD CLASSIFICATION DECISION MATRIX

Default Starting Ranks: [UK] [IRL] [DE] [FR] [IT]

INTERSTATE/MOTORWAY motorway [US:I] [UK:M] [IE:M] [DE:A] [FR:A] [IT:A]

NHS (DIV) trunk [UK:A(T)] [IE:N] [DE:B] [FR:N] [IT:SS]

US (ALL) / NHS (UNDIV) primary [UK:A] [IE:N] [DE:L] [FR:D] [IT:SS]

STATE PRIMARY secondary [UK:B] [IE:R] [DE:K] [IT:SP]

STATE SEC/COUNTY tertiary [UK:C]

TOWNSHIP residential

other things to think about for status changes: for Primary to Trunk: NHS mainline/some Strahnet (exc intermodal connnectors) +1 controlled access (limited intersections) +1 divided highway +1 interchanges at intervals +1 super-2 in places +1 or upgrade to motorway super-2 with widened centerline, rumble strips, mandatory headlight usage. Trunk means “watch out”; dangerous roads serving the role of a motorway one with design/safety compromises.

Secondary to Primary: high relative traffic +1 wide shoulders +1 Interstate Business Route +1 (not automatically in NHS!)

Tertiary to Secondary: 4 or 6-lane divided +1 through route +1 retail strip +1 interchanges with an Interstate (case-by-case)

Residential to Tertiary Divided, serving major retail centers and industrial parks +1 MD: Has yellow center line and is through/collector route VA: Numbered Secondary 600-999, selected routes above 1000 (VA numbers almost every road, but these lower numbers are usually important) PA: Numbered SR 1xxx-4xxx WV: County Routes (whole & fractionals)

for drops in status: numerous traffic signals in quick succession (drop from trunk) -1 retail strip (usually cause for above): drop from trunk to primary, but up from tertiary to secondary if divided. -1/+1 low speed limit -1 city environment -1 narrow shoulders -1 twists/turns/grades -1 (in relation to nearby straighter roads serving the same general direction)

NHS Overview: If divided and few intersections: trunk If connecting sections of full motorway or alternates between: trunk If undivided but otherwise controlled access: trunk Super-2: motorway with oneway=no

If undivided without controlled access: primary If divided without controlled access, many cross streets: primary

Discussion

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