See what I found out about the founder of that plugin osm.wiki/Relations/Proposed/turn_lanes

He was active in OSM-wiki for less than four month in 2011 osm.wiki/Special:Contributions/Benshu

As far as I see he never mapped active osm.org/user/benshu

So please form your opinion ;-)

And as noted in the margin: In and arround San Francisco you find more than 400 ways mapped with key turn:lanes or turn:lanes:* http://overpass-turbo.eu/s/aH9

To know what we talk about: Have a look here osm.org/edit#map=19/37.66245/-122.39964 and try to find out what the up to four relations on some ways want to say to you without using that JOSM-plugin. Are you able to find out only by relations, which lane gides you best through crossing without Bing as background?

We should prefer solutions transparent enough to be created, read, changed and understood without any tools. Therefore this plugin isn’t suitable. Remember that most of people creating OSM-Data are volunteers and we should allways keep KISS in sight.

And just one question about length-tag: How do you get exact measure with that plugin?