Forum:Ingrea/Road classification and numbering
Hi! I recently reached out to Alessa about road classification and numbering. I realise that there is a proposal from 2024 about this, but from what I can tell, it went nowhere.
From what I can see, the current road classification is a bit of a mess. In one region, the motorways are right-hand-drive instead of the left-hand-drive that the country is marked as. In addition, there is no concrete road numbering system.
We could adopt a UK-like system for numbering, but I personally have found that very hard to interpret in the past. However, I like the US system of numbers implying where in the country the road runs. So here is my proposal:
Classification
- M roads: these are motorway roads. These roads are key routes within Ingrea. These will be tagged as highway=motorway, obviously. Exits will ideally be sequentially numbered and not distance based, b/c in my experience, distance-based numbering is really hard to pull off.
- P roads (alternatively could be called A roads): these are major highways that aren't motorways. These will be tagged as highway=trunk.
- S roads (alternatively could be called B roads): These are less-important highways. These will be tagged as highway=primary.
- This leaves highway=secondary for important roads within a city and highway=tertiary for smaller city arterials.
Numbering
M roads
- East-west highways have an even number. A higher initial number suggests that it is in the north, while a smaller initial number is in the south. Major east-west routes will have a number ending in 0 (like M10 or M90).
- North-south highways have an odd number. A higher initial number suggests that it is in the east, while a smaller initial number suggests that it is in the west. Major north-south routes will have a number ending in 1 (like M1 or M91).
- I don't have plans for sub-routes (i.e. in the vein of Interstate auxiliary routes) at this time, but I'm sure we can figure that when we need it. We could always add a suffix like W, N, E, or S.
P/A roads
- To avoid confusion, these routes will be numbered in a different direction.
- East-west highways will have an odd number. A higher initial number suggests that it is in the south, and a lower initial number suggests that it is in the north. Major east-west routes will have a number ending in 9 (like P9 or P99).
- North-south highways will have an even number. A higher initial number suggests that it is in the west, while a lower initial number suggests that it is in the east. Major north-south highways will have a number ending in 8 (like P8 or P98).
S/B roads
- These routes will be numbered according to what region number they're in. For instance, an S road in region 9 might be numbered S0922, while an S road in region 12 might be numbered S1201. Unlike M and P roads, the number of these roads does not imply direction.
M suffix for P and S roads
- Should there be a rare instance in which a P or an S road takes the form of a motorway, they will have "(M)" appended to the end, e.g. "P1 (M)". To me, it would be highly unlikely that this would apply to S roads.
- If there's a gap in a numbered motorway, I'm really not sure how to number that. This thought came after seeing Breezewood, Pennsylvania.
Misc
- Exit numbers would likely reset per-region.
Feedback welcome!
datmapper (talk?) 18:33, 21 September 2026 (UTC)
- On second thought, it'd probably be better to number exits based on kilometres (east to west and north to south) and not sequentially, as that could get chaotic. I'm assuming that we're using km here as I've already added speed limits in km/h. I think I'll try distance-numbering the Hale Expressway to see how well that goes. datmapper (talk?) 03:30, 7 October 2026 (UTC)
I don't know... In the same way as if radial numbering was proposed for the Federal States, I find it jarring to propose grid based numbering here. Review wikipedia:Great Britain road numbering scheme and think about a single radial numbering scheme centred on the capital. Similar for the prefixes, M, A and B will be natural for those expecting to map in UK style. I think the past discussion proposal Forum:Ingrea/Transport#Roads makes sense. /wangi (talk) 12:12, 9 October 2026 (UTC)
- Fair point you make there; I was trying to propose a simple scheme, but I'm not really opposed to the radial scheme, despite the fact that it appears quite confusing and convoluted in the UK, considering the fact that they have two different radial systems for M and A/B. datmapper (talk?) 18:38, 10 October 2026 (UTC)
I take it you're not UK based, and your take about confusion is based on a wiki page, which overdoes the M vs A, rather lived experience? It's really pretty simple and arguably much more so than grids from this to that, incrementing and decremented, ending zero, not ending, spurs and what not. /wangi (talk) 19:43, 10 October 2026 (UTC)