Modal filtering

aggi:

In terms of rat-running I do wonder what difference google maps, Waze, etc has made to it.

As others have said, it has definitely made a difference, although I feel that is now a long time ago (not quite when massive lorries were getting stuck between drystone walls on tiny country lanes, but certainly when people started to use satnav systems heavily). I doubt that the effects will have worsened that much after the initial shock of the new, but it would definitely be interesting to see data, which should be easy to map. I've never looked at it as I think filtering should be done as a matter of principle,

The danger is that with the additional pressure to filter, some of which has undoubtedly come on because of on-line/app/whatever routing information and drivers rat-running/driving at inappropriate speeds down inappropriate speeds/causing more crashes, you then end up with an additional impetus to increase motor traffic capacity on the perimeter as a way to compensate--i.e., something very similar to what has been happening to town centres/high streets up and down the country for decades, e.g. in Waltham Cross--high street filtered and a massive by-pass/ring road built.

I see this in the context of the absurd situation that we supposedly have a £27bn road-building budget (which I hope now won't get spent, but I suspect it will be regardless), which would mainly increase capacity around the perimeter of centres, and at the same time a drive to filter local areas (in places like London and Brighton (I think) at least. Obviously, in London it won't easily be possible, short of changes in signalling methods (on-demand signal phases etc.) to increase perimeter capacity, and apart from the Silvertown Tunnel and the constant agenda to increase capacity on the North Circular, no really massive road-building projects are planned imminently, but the mistake of 'compensating' for filtering by making it easier to drive around centres must be avoided. Most European countries have made that mistake--the upshot is that larger centres benefit disproportionately, as people avoid the smaller centres by driving around them (using those convenient ring roads and the like) and then shop/go out/etc. in larger cities. This in turn causes the economy of smaller centres to suffer, leading to business closures and job losses there, in turn causing people who previously had worked quite locally to have to commute further afield, and so on.

The majority of the time I'll get it directing me off an A road to a B road to avoid traffic (routes are almost identical length or the diversion can be longer). For those who know it the most obvious one is that you get directed off Green Lanes/Seven Sisters onto Wightman Road/Tollington Park almost every journey. You can see that a lot of traffic is also following the same diversion as people will all turn at the same points, etc

I think where you get the effect of satnaving isn't so much on streets like Wightman Road, which has been a problematic rat-run for decades, but on the more minor streets. One of the things I do when I look at local areas is to follow the rat-runners around. They're always easy to spot because of aspects of their driving style, and as they typically don't get through local areas more quickly than me on a bike, I usually get a very clear idea of what they're doing. It's obviously never very clever stuff, as a bit of work with a map will usually show very easily where the likely rat-running alignments are (following decades of haphazard pseudo-filtering and alternating one-way operation schemes, it's usually the loopholes that people use, and those were always known to locals long before satnavs came along), but always interesting to see it being enacted live, as you get to see the conflict points, where queues develop first, etc.