Streets shape the way that we think of our cities. They constitute most of our public realm, dwarfing the amount of space we devote to formal parks. They have enormous power to define the relative quality of our daily lives, yet for the most part all we seem to ask of streets is that they get our cars from one part of the city to another as quickly as possible. living streets urbanism | health , safety , beauty by ken and rita brooks speed traffic safety engineering friends
The Open Planning Project http://topp.openplans.org/
1 Asking little
Safety I remember an old ad campaign with a simple tag line: Speed Kills . Blunt and to the point, it captures a truism of safety: ‘a variety of factors may contribute to a collision, but the outcome depends on the speed the car is travelling’. 2 A British government study found that when vehicle speeds were reduced from 60 kph to 30 kph, pedestrian deaths dropped from 85% to 5%. 3 There are several ways in which living streets contribute to a reduction in the speed of traffic. Reducing lane widths to accommodate a multifunctional streetscape is one very simple and effective way. The city of Longmont, Colorado examined 20,000 collisions over an eight year period. They found that ‘as street width widens, collisions per kilometre increase exponentially’. Tree- lined streets also contribute to reducing traffic speed. Research has shown that drivers go up to 20 kph slower on a street with trees than they do on one without. 4 However one of the best ways to slow cars down is to have lots of people out on the street – socialising, entertaining, just watching their children having fun. David Engwicht, a traffic calming activist from Australia, refers to the effect that a spontaneous, vibrant, social street life has on traffic, as mental speed bumps . 5 Another interesting and perhaps surprising benefit of reducing lane width to slow cars down is that this helps to maximise the efficiency of the carrying capacity of roadways. The fact is that no matter how fast traffic moves, the number of cars a lane can carry stays roughly constant. You can’t move more cars by speeding them up, because the increased amount of space required between cars outweighs whatever gain you think you might make. A car lane reaches its peak capacity when cars are travelling roughly 40 kph (25 mph); that is, at a nice safe speed. 6
It is difficult to design a space that will not attract people. What is remarkable is how often this has been accomplished. —William Whyte 1
when we say ‘street’ we think river of asphalt . Turning 50% of our urban area to the passage and storage of cars has become normal. Lousy streetscapes don’t just happen, it takes hard work, a lot of money and the commitment of an astonishing array of enablers to suck the life out of streets. Our streetscapes are unloved not because they are neglected; love is irrelevant. Take another look at the image above, again. In a 20th century functional exercise, our streetscapes are in the hands of traffic engineers who distill streets to a single purpose – to maximise the unimpeded flow of traffic. Our streets are designed as traffic sewers. If we thought of our streetscapes more as living rooms and less as corridors, we would find ourselves a lot closer to fully utilising our streets as real public assets. We need to stop engineering traffic corridors and start designing living streets. Living streets are — 1. multipurpose public spaces that embrace walking, cycling, sitting, shopping, dining, transit and usually but not always, cars. 2. active social spaces for meeting, playing, entertaining and one of our favorite pastimes, people watching. 3. alive with vegetation, including trees and gardens just like the linear parks they should be. 4. beautiful, have clear spatial definition, express the character of individual streets and contain elements of surprise and delight. These characteristics of living streets have two interesting and interrelated consequences: they slow down traffic and they create inviting places for people to be. These may seem at first to be nice but underwhelming attributes but they have a lever effect on creating some pretty remarkable side benefits.
onsite 19: street, streets and lanes, the straight and narrow, wide and busy
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