Local "L" roads are the responsibility of the local authority for the area. L road numbers are unique to the county and may be repeated in other parts of the country.
Suggestions only from AndrewMcCarthy based on experience.
Road refs from signs only
Apart from road schedules, the main source of local road numbers are road-side signs. It is completely unpredictable how much of a side road carries a given number, so if using signs only, please split the side road at the next junction and only tag the first segment to avoid tagging "too much" road.
All local road refs stop at the county boundary. Split all local roads at the county boundary before adding a L number to one side or the other.
Since the highway=tertiary/unclassified doesn't cover our three levels of local roads, please add local_class = primary/secondary/tertiary to each road also.
As a shorthand many council documents include the road class in the number, e.g. LS6789 to indicate L6789 is Local Secondary. In cases like this, use ref=L6789 and local_class=secondary.
Reference numbers are usually in ranges, but on rare occasions there may be some overlap. Best not assume primary, secondary or tertiary just on the number alone. E.g. Laois L5032 is the start of local secondary numbers but L5732 is an odd, high-numbered primary.
Some local roads are split into sections by the council. For example the L1234 may be listed as L-1234-0 and L-1234-15. In this case keep ref=L1234, but also add loc_ref=L1234-0 and loc_ref=L1234-15. For roads that are in a single section, e.g. just L-1234-0, omit loc_ref altogether.
Splits such as these sometimes occur in the middle of the road rather than at an obvious junction. We can use the published road lengths to estimate where this split is, although road measurements in OSM will rarely match exactly with the published lengths.
It seems that motorway on/off ramps are listed in the local road schedules. Suggest adding L-number with loc_ref only.
Under Section 10 of the Roads Act 1993, every local authority is to maintain a list of local roads, called the "Schedule of Local Roads", and to have it available for inspection at their offices during working hours (Part 5(c)).
In practise, it doesn't seem to be this straightforward at all. Local councils are wary of providing this information because:
- They may not have a human-readable schedule ready, as it's probably stored in a GIS system. Laois said I was the first person to ever ask for it.
- Typically their schedule is out-of-date due to the large amount of development recently, both residential and massive road rearrangement caused by new motorways, etc.
- Due to their nature, they're likely to contain errors here and there, and they are afraid that by providing it to us that some liability might rest with them for any errors.
- It's not entirely clear for many roads whether they really are the council's responsibility. The council may have done some work on rare occasions on an informal basis on roads they're not strictly responsible for, and then locals insist many years later that since they did this work the council must really be responsible for it after all.
So, when approaching them it may be best to emphasise that you're quite willing to accept the document may have errors or be incomplete, and that you're simply looking to expand OpenStreetMap with whatever information you can. Best to visit in person rather than by e-mail or phone; most that I have rung seemed okay with the idea but I hear nothing further.
See full schedule on Ireland/Roads/Carlow.
See full schedule on Ireland/Roads/Cork.
See full schedule on Ireland/Roads/Kildare.
See full schedule on Ireland/Roads/Laois.
See full schedule on Ireland/Roads/Louth.
See full schedule on Ireland/Roads/SouthDublin.
See full schedule on Ireland/Roads/Wexford.