> lit=weak is too subjective. > disclaimer: I am trying to make lit=yes/no definition more precise as > part of my grant > https://www.openstreetmap.org/user/Mateusz%20Konieczny/diary/368849
There is a lot of open access academic literature on your topic, covering objective measures and both subjective indicators and how to derive objective means from subjective factors. There is also more than a few international and national design standards, guidelines, and other to form the basis of your own 'definition'. For example "Pedestrian and bike path illumination for safety and security: empirical pre- and post-field studies by a university team" at https://www.witpress.com/Secure/elibrary/papers/UT13/UT13060FU1.pdf You'd probably be okay using the 10 lux indicated by the Illuminating Engineering Society. But considering that the illuminate area is uneven ( a notion also covered in the standard ) and usually fairly extensive, and illumination measurement is a technical skill, and it is a moving target because of the daily cycle and weather, it probably isn't practical o expect some member of the general public to collect the data. However, there is also a considerable work that has been done for measuring direct and ambient light levels by remote sensing, and correlating those with on the ground conditions - the only practical way to cover any significant area since values can be accumulated over time ( by hour to seasonal ). See https://ars.els-cdn.com/content/image/1-s2.0-S036013231830550X-fx1_lrg.jpg and https://res.mdpi.com/remotesensing/remotesensing-10-01964/article_deploy/html/images/remotesensing-10-01964-g001.png It still leaves the question how you'd apply any data to a way element - do you break it into smaller segments to apply differing values as they change along the route? Also, what is the specific use case? i.e. is 'lit' really a proxy for some aspect of safety or reassurance, in which case the illumination level doesn't matter at all, rather the unevenness, sight lines, and other factors that affect a (only?) pedestrian's feeling of reassurance and safety. For instance, no matter how bright a path itself is lit, if that lighting produces impenetrable shadows within arms length of my path, it feels dangerous - an conversely, a unlit wide open field of short grass feels perfectly safe. This is a well researched topic, since, like 1285, when English King Edward I forced property owners to clear highway edges of trees and shrubs. :-) Michael Patrick Geographer <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail&utm_term=icon> Virus-free. www.avast.com <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail&utm_term=link> <#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>
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