-
Thanks Oliver, I appreciate the info. I don't really know about it other than my observations from local schemes so every little bit helps.
There was a modal filtering point introduced to South Row in Blackheath village last year. The end of the street blocked off to cars was/is an accident hotspot. Several fatalities and quite a few more serious accidents involving pedestrians and cyclists. As a local I thought it looked like a sensible change. The backlash it generated was huge. Initially the council stuck to their guns but got sick of having to replace the planters every day as angry locals dragged them out of the way. Would be interested to understand why the locals seemed so opposed that particular scheme.
Edit: Maybe it was more of a case of being poorly implemented https://853.london/2020/06/19/south-row-blackheath-walking-and-cycling-scheme-suspended-after-drivers-ignore-signs/
Stonehedge-
Well, that's just a classic case of filtering in the wrong place. The single principle for getting it right that gets violated by far the most often is to filter at the edge of a cell instead of inside, but this isn't even a case of that, as South Row functions as a cell boundary street. I wouldn't filter it. Sure, that junction may have had its fair share of crashes, but the reason for those was people making fast, injudicious turns, whether into or out of the junction, and your first remedy there is to simply square off the junction. You can see how the corner was built out there before, but that's not nearly enough. The traffic engineer involved will have had a brief not to make turns too slow, and it's true that if you make them very slow you may get rear-enders, so you'd need to make sure the junction is very obvious to drivers on Montpelier Row and Prince of Wales Road. However, that crash potential would be a much more minor problem compared to the existing problem of the aforementioned fast turns. It's often the junctions with the sweeping angles that cause so many crashes from those, and that problem would be removed almost entirely if you extend the existing build-out so that South Row meets the B212 at a right angle. The junction of South Row and Paragon Place so close to the main junction is a slightly complicating factor, but not impossible to design right.
It's certainly daft in the extreme to stick a single filter there while leaving Paragon Place and Wemyss Road unfiltered. Whoever did that job evidently didn't see the Obvious Problem.
I think filtering further back in the cell, i.e. around Morden Road/Blackheath Park would make the cell to the south too large. (The main culprits in the lack of permeability to the south are the large private estate there, the railway lines, and the fact that Blackheath Park does not connect to Kidbrooke Park Road, only to Morden Road.) I'm sure you already have the problem there that drivers accessing their houses drive too fast to get to them, which is what usually happens in very large cells, and were Morden Road filtered (as Pond Road and Fulthorp Road/Morden Road Mews undoubtedly were a long time ago), the resulting cell would be massive (bounded by the A2213, Weigall Road, the A20, the B212 (including the immensely annoying Blackheath one-way system), as well as South Row, Kidbrooke Gardens, and Westbrook Road). It is already filtered in the usual number of places were older problems were undoubtedly addressed in this way, e.g. between Casterbridge Road and Moorhead Way.
Paragon Place/Wemyss Road could be filtered, but I'd guess that they don't often have to take overspill from congestion on the Blackheath one-way system. It's really up to what the locals think. Of course, further filtering could be introduced in the cell south of Blackheath Park. The large number of private roads, e.g. Manor Way probably means that there's no existing rat-running problem.
Oliver Schick
The furore in the cabbies' case was mainly aimed at the introduction of these schemes without consultation. Obviously, they'll also be unhappy about what exactly has been done, but this was ostensibly about procedure. Highway authorities have every right to introduce traffic orders, and wide leeway as to what they can contain, but it has to be said, and I say this as a supporter of modal filtering, that many of the schemes are terrible and not on the right principles. The Greenwich one is a rare example of a well-conceived scheme, but most contain the usual problems with filtering--filtering on the edges of cells, making cells too large, leaving loops, failing to filter cells properly, etc. Also, some of the measures aimed at widening footways essentially created conditions comparable to ones you find at roadworks, which are known to be more hazardous than ordinary conditions, and generally prevented people from crossing the street.
Anyway, I didn't expect this case to go the cabbies' way, and I was surprised when the first judgement did, but it's certainly not the last word on this.