| Topic: | Re:Re:Re:Independent on air quality limits - Impending court case | |
| Posted by: | Richard Hodges | |
| Date/Time: | 25/03/13 15:47:00 |
| As you should have realised by now, I spent a considerable time of a former life in the industry, with a fair chunk on the theory and practice of engine emissions. I have been through the Type Approval process, which the reports failed to mention is an extremely long and political process of negotiation with several legislative bodies in each country. There are tight controls on how mandated tests need to be carried out, and agreeing which specific model types need to be physically tested. This is not a process that can be easily abused, not least because some organisations, by which I mean the French, can be distinctly unhelpful. I have also been party to the physical tests, so I know how much wriggle room there is, and it's not a lot. The ongoing narrative for the last three decades of so has been that cars are bad. An extension of this is that car companies have to be evil - like Big Oil. So which to believe - a story retweeting claims the manufacturers are cheating, or the off-message truth of what it would actually take to cheat. The damage that causes can be seen even in the comments between your post and this - a continued lack of understanding of the emissions sources here in Putney, even though I've explained it at great length. I amy as well be talking to a brick wall, but if we continue working from false assumptions there will be no progress. What you'd struggle to pick up is quite how much expertise we have in Britain. Companies like Ricardo and even boring-old Perkins are world-leading, and doing stuff beyond even my comprehension (and I was trained in the field). As to where we have to go next, it's pretty much what I've been saying for the past few years, with one addition: - Fidelity of the results Measurements on PHS are a statistical anomaly compared to all other sites in London. Why? Why are PHS results higher even than sites that carry higher and worse traffic? Something is happening that hasn't been explained, and until it is, we're shooting blind. - Audit of Sources All attention has been focussed on traffic (and still in some minds just cars, when that particular falsehood has been explained). Background levels in Putney are also fairly high, even though traffic effects will be limited. Why is that? I can see three major sources of NOx upwind of Putney - low-level aircraft, domestic boilers in concentration, and sewage works. Traffic Flow Management Easily the best thing you can do to reduce per-vehicle emissions is to smooth the flow - not faster, just smoother. The easiest element to deal with is the unnecessary blockages (in this context, I think all the crossings and traffic lights are both necessary and performing pretty well). - I have still not heard a good reason to maintain the WH Smith bus-stop, and three good reasons (pollution, safety and pedestrian traffic) for its removal or restricted use. - Delivery vehicles make up the next greatest blockage to flow. As many have noted, there are the usual suspects, but there are others who do the right thing. There are carrots (ie providing them with better parking options) that can be offered to these vehicles, which in time might allow for - Use of the big stick - changing the High Street to red route from bridge to URR. Smoothed, managed traffic flow will not only reduce vehicle emissions, it improves safety for all road users. System Optimisation Walking the High Street and environs, you should be able to see problems and practical solutions that can be employed rapidly. These might include: - Tweaking road layouts to clarify and calm - Encouraging short distance walking and cycling (If the cycling bays outside Sainsbury's are regularly full, it's probably time to make some more space). The same goes for motor cycles. The Council have already got some of these principles down, but there are a good dozen that should be on the list, including a couple that could be activated tonight. (new item) Selective Catalytic Reduction Having accepted that their vehicles are the overwhelming traffic source for NOx, TfL have committed to replace and upgrade existing buses. The upgrade option means fitting SCR units, which by TfL's own claims might reduce NOx emissions by "up to 88%" Except. TfL's own research suggests SCR may not work in the real world conditions. Further, the retro-fit package requires regular maintenance and my inside line from the Putney Garage is that's not a good thing to be trusting too much. So what accountability and real-world assessment is there of the upgraded vehicles. How will they be checked, and how frequently? Will failing vehicles be withdrawn from service, or will a blind eye be turned? Who's monitoring this, and what happens when it doesn't deliver the results. |