<html> <head> <META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=us-ascii"> <meta name=Generator content="Microsoft Word 10 (filtered)"> <style>  </style> </head> <body lang=EN-US link=blue vlink=purple> <div class=Section1> Dear Dave, Lee, Peter and colleagues,   As you all know, on the “how to” side this is well plowed terrain -- the rich literature and our best sources are chock full of all kinds of ways and stuff that works quite nicely in this context. Using parked cars to slow down moving vehicles is just one of many. At the leading edge we now have a solid thirty year track record of accomplishment and different ways to achieve this, and it can safely be said that the entire slow-street movement is steadily gaining in momentum and unimpeachable on-street results.   But the crux of it all is what I and others keep calling the Politics of Transportation, and right behind that the firm grounding that we have in our multiple records of life experience on the street in many many settings, and right behind that in turn the work of a number of behavioral psychologists how have looked at all this quite cogently and with pretty much unanimous results as to the “why” part of this.   My own preference is to take this in deliberate steps. Here is one possible succession:   <ol start=1 type=1> <li class=MsoNormal style='color:black;margin-bottom:12.0pt'>Sell the idea to your highest local political authorities (and civil society who we shall need to have firmly behind us) that indeed this basic thesis is solid, i.e., (a) that drivers as a group will drive as fast as the conditions permit them to and with that (b) that the only way to get them moving at acceptable speeds is by modifying “street architecture” so that they simply cannot go beyond the speed which the community has adapted as safe on their streets. Now this is quite a sale, as you will see if you try it. It goes against the grain of policy and practice in the past, and unlearning is one thing that most people are not very good at.  (Though a properly desperate politician or one who wants to win that next election may turn out to be a faster unlearner and hence a better partner for this kind of operation.)</li> <li class=MsoNormal style='color:black;margin-bottom:12.0pt'>Once they bite for that idea, there may be a push here and there to try to demonstrate how technique x or y can get some results. As long as this is done intelligently and with proper professionalism, it is better than nothing -- but for my part I think we need to see if we can possibly in parallel develop all this as part of a more radically revised comprehensive vision of our mobility system and its main components (again the Politics of Transportation, and if you want a bit more on that you might have a look at what I propose under the Philosophy link on the top menu of my recent “Letter to London” at http://www.newmobilityadvisory.org/tfl.htm. ).</li> <li class=MsoNormal style='color:black'>Please do not take this as a plea for yet more studies and tergiversation. We collectively know what we need to know in this case, and the only thing that is needed here is to make sure that we bring the right people and competences into our demonstration projects. </li> </ol>   So if you really decided that you wanted to make a convincing high profile demonstration of these principles all you would need would be your couple of good shopping lists, the sense of priority that is need, the bit of budget that it would require, a locality that truly wishes to work with you to make this a success, and you have yourself a sure winner. (And I and others whom you know can help you build these shopping lists and get this process started within days.)   To conclude with one quick question and one quick answer: ·   Question: How much is the life of a single Londoner worth these days? And ·   Answer: the cost of one cm. of a new metro system runs anywhere from $400 - $1k.   Now what?   Eric Britton   <div style='border:none;border-bottom:solid windowtext 1.0pt;padding:0cm 0cm 1.0pt 0cm'>   </div>   -----Original Message----- From: Lee Schipper [mailto:SCHIPPER@wri.org] Sent: Sunday, December 31, 2006 4:50 PM To: eric.britton@ecoplan.org; eric.britton@free.fr; LotsLessCars@yahoogroups.com Subject: Re: [LotsLessCars] Why do people speed?   This also leads to a speculation of mine Eric, so thanks. Is it possible that in a moped-based city, like Hanoi, that at least in the most crowded areas traffic is kind of self limiting in speed, people are so close to each other that they ARE on guard (despite horrible violations of lane discipline) and the whole things actually works...   While in the  outer reaches of Hanoi, or in Indian cities, there is so much room for speeding that  the system doesn't really work?   If I am right about the  dense parts of Hanoi and the self-speed limiting nature of motorbike speeds  in very dense cities, then not only might slow, low-powered mopes make sense, but electric bikes as well, which cannot go much over 10 km;/hour, could be the "next step" if  it could be shown that they provide essential low emissions, low speed, low risk and low footprint mobility in combination with mass transit, and in place of cars?   Happy Safe New Year to everyone   lee <div style='border:none;border-bottom:solid windowtext 1.0pt;padding:0cm 0cm 1.0pt 0cm'>   </div> -----Original Message----- From: Wetzel Dave To: 'eric.britton@ecoplan.org' <eric.britton@ecoplan.org> Sent: Sun Dec 31 14:29:37 2006 Peter, Could we conduct an experiment on a road which has no bus routes but a bad safety record?  Happy New Year, Best Wishes, Dave Dave Wetzel Vice-Chair TfL Tel: 020 7126 4200 --------------------------   -----Original Message----- From: Wetzel Dave To: 'eric.britton@ecoplan.org' <eric.britton@ecoplan.org> Sent: Sun Dec 31 14:29:37 2006 Subject: Re: Why do people speed? CHEERS Eric, Perhaps we should allow more cars to park at kerbsides - this would reduce road width without any expensive engineering? Or how about lamp standards for street lighting being placed closer together so that drivers gain a feeling of greater speed?  Happy New Year ! Best Wishes, Dave Dave Wetzel Vice-Chair TfL Tel: 020 7126 4200 --------------------------   -----Original Message----- From: eric.britton@free.fr <eric.britton@free.fr> To: eric.britton@free.fr <eric.britton@free.fr> Sent: Sun Dec 31 14:00:44 2006 Subject: Why do people speed? Dear Friends, Here is what we have observed on this subject over quite some years in city after city, road after road and study after study, in many places around the world: 1.       The simple fact is that we need to understand without equivocation that some no trivial number of drivers (let’s perhaps think of them as that dangerous 15% or so – not everyone at a wheel but enough such that we need to make them our protective design target) will drive as fast as they think they can without having an accident or hurting themselves.  (This is as true of motorized two wheelers as that car you so love.) 2.       This is a simply human condition – and indeed when any of us are behind the wheel, we develop a level of time impatience which is considerably beyond that which we feel in much of the rest of our daily lives. Thus cars by their very nature actually evoke impatience, and with that speed and risk. This you either understand or you do not. It is unequivocal and any responsible community  leaders of active citizen must understand this and be prepared to act on it.  (Many of us also like to zip right along on our bikes too, which also needs to be taken into account in a well designed street system (as you all know so well.)) 3.       We must protect ourselves, our children and our communities from these very human but ultimately very dangerous modes of behaviour. 4.       The best way – indeed I think the only way – to accomplish this surely and safely in cities is therefore to design our streets and roads for top speeds that are way way below what the traffic engineers have long worked with.  The tools of this are well known and include the full gamut of stuff like undulating streets, no long stretches of straight road ahead, narrow streets, pavement surfaces, proper lighting, plenty of non-car users out there for all to see . . . and the long list goes on. 5.       My own personal target for cars on most city streets is a max of 15 kph – a nice cycling speed, which also leads them to a point in which they can safely and civilly share the street with other users.  On the other hand I would like to see 6.       etc. etc. But if that is true – what do we do with it next? Eric Britton ---- -----Original Message----- From: Michael Wallwork [<a href="mailto:mjwallwork@comcast.net">mailto:mjwallwork@comcast.net</a>] Sent: Saturday, December 30, 2006 4:21 PM  Subject: RE: The 85th Percentile A NEW program??? David Engwicht raised the issue of how people based their vehicle speed on their feel of the road many years ago and was able to demonstrate how drivers drive with a margin of safety irrespective of the posted speed. This is the underlying reason people speed. Michael Wallwork, P.E. President Alternate Street Design, P.A. (904) 269-1851 www.roundabouts.net ---- 85th percentile rule (From Wikipedia) In the United States, traffic engineers may rely on the 85th percentile rule[2] <<a href="http://en.wikipedia.org/wiki/Speed_limit#_note-1#_note-1">http://en.wikipedia.org/wiki/Speed_limit#_note-1#_note-1</a>>  to establish speed limits. The speed limit should be set to the speed that separates the bottom 85% of vehicle speeds from the top 15%. The 85th percentile is slightly greater than a speed that is one standard deviation <<a href="http://en.wikipedia.org/wiki/Standard_deviation">http://en.wikipedia.org/wiki/Standard_deviation</a>>  above the mean of a normal distribution <<a href="http://en.wikipedia.org/wiki/Normal_distribution">http://en.wikipedia.org/wiki/Normal_distribution</a>> . The theory is that traffic laws that reflect the behavior of the majority of motorists may have better compliance than laws that arbitrarily criminalize the majority of motorists and encourage violations. The latter kinds of laws lack public support and often fail to bring about desirable changes in driving behavior. An example is the federally-mandated 55 mph (90 km/h) speed limit that was scrapped in part because of notoriously low compliance. Traffic engineers observe that the majority of drivers drive in a safe and reasonable manner, as demonstrated by consistently favorable driving records. Studies have shown crash rates are lowest at around the 85th percentile. Vehicles traveling over the 85th percentile speed (or faster than the flow of traffic) have a significantly higher crash risk than vehicles traveling around or modestly below this speed. Most U.S. jurisdictions report using the 85th percentile speed as the basis for their speed limits, so the 85th-percentile speed and speed limits should be closely matched. However, a review of available speed studies demonstrates that the posted speed limit is almost always set well below the 85th-percentile speed by as much as 8 to 12 mph (see p.88) <<a href="http://trb.org/publications/nchrp/nchrp_rpt_504.pdf">http://trb.org/publications/nchrp/nchrp_rpt_504.pdf</a>>  (13 to 19 km/h). Some reasons for this include: *       Political or bureaucratic resistance to higher limits. *       Statutes that restrict jurisdictions from posting limits higher than an arbitrary number.   </div> </body> </html>