Análisis de una propuesta de arquitectura

To better elucidate the problem, by comparing trends and measuring the effects of different policies and infrastructure investments globally, Dr Jeff Kenworthy has built the Global Cities Database (GCD). It regularly updates the metrics regarding cities, their urban area, population, density, transport services and a multitude of other sub-data. From these numbers we can gain insight into trends regarding density, transport use, mode splits, and relative automobile dependence. (Please see ‘Urban Areas, Populations and Transport in 19 Cities’ and ‘Select cities from the Global Cities Database’ in the Appendices). The main lesson from the GCD is certainly that the less dense a city, the more energy is used for transportation. While seemingly intuitive and noticed subjectively by many (that Parisians, say, drive less than those in Houston) this was the first large scale study to objectively place the cities in direct comparison. Along with a host of other partially explanatory factors such as kilometres of highway and transit, we could finally see through a miasma that if a reduction in automobile dependence was a goal then we must supply more transit kilometres and create overall denser cities.

Literature Review Page 53

…the physical layout of a city does have a fundamental impact on movement patterns (Newman & Kenworthy, 2006 p.42).

Since this was first published it has been widely cited and foundational to the discussion about sustainable cities. However, despite this, not a great deal of physical action has been taken until recently where a shift has been noted. Current trends in driving and transport use have recently been compared which demonstrate:

… new data on the plateau in the speed of urban car transportation that supports rail’s increasing role compared to cars in cities everywhere, as well as other structural, economic and cultural changes that indicate a move away from car dependent urbanism (Newman, P et al., 2013).

This analysis has been illustrated by others such as the Department of Transportation's Federal Highway Commission data on the decline in driving. As we see in the following figure, since 2004 there has been a sustained decline but the trend was levelling off slightly earlier.

Literature Review Page 54 Figure 7 Vehicle Miles Travelled (billions)

SOURCE:“TRAVEL MONITORING AND TRAFFIC VOLUME”USDOTFEDERAL HIGHWAY

ADMINISTRATION,OFFICE OF HIGHWAY POLICY INFORMATION

HTTP://WWW.FHWA.DOT.GOV/POLICYINFORMATION/TRAVEL_MONITORING/13DECTVT/FIGURE1.CFM

ACCESSED JANUARY,2014

These findings have been reinforced by Doug Short, a former professor and IBM Consultant who now specialises in charting financial data. He used the same Department of Transportation's Federal Highway Commission’s data and crossed it with the growth in population to find even starker decline in per capita driving for all Americans over the age of 16 (Short, 2014).

Literature Review Page 55 Figure 8 Estimated Vehicle Miles Driven on All Roads

SOURCE:““VEHICLE MILES DRIVEN:ANOTHER POPULATION-ADJUSTED LOW”

HTTP://WWW.ADVISORPERSPECTIVES.COM/DSHORT/UPDATES/DOT-MILES-DRIVEN.PHP ACCESSED

JANUARY,2014.

The results show a marked decline in driving beginning from 2005, well before the 2008 Global Financial Crisis. What, besides the price of gasoline (petrol), is behind this?

M I L L E N N I A L S

One of the most recent surveys done on Millennials’¹ preferences, and especially their preferences for mobility, was recently published by the Rockefeller Foundation of

1 Millennials: Defined as those born from 1982 to 2004 and tending to use Wikipedia. “Millennials”:

http://en.wikipedia.org/wiki/Millennials. Accessed May 8, 2014

Literature Review Page 56 New York and complied by Global Strategy Group (Global Strategy Group, 2014; Rockefeller Foundation, 2014) and found that:

54% of Millennial respondents would consider moving if another city had more and better transit options;

and:

47% of Millennials would give up their cars if their city had robust public transportation.

It concluded that:

… cities that don’t invest in effective transit solutions today stand to lose out in the long-run. Providing public transportation options has moved from a nicety to a necessity. As we move from a car-centric model of mobility, and become a nation that embraces more equitable and sustainable transportation options, Millennials are leading the way (Rockefeller Foundation, 2014).

According to the survey, Millenials drive less than their parents and, furthermore, aspire to drive less. They would rather spend money on electronic goods which bring them closer to other people via social media and on life-reaffirming experiences such as those experienced in the urban public realm. They prefer to live within neighbourhoods in cities with good public transport access to many places, shops, jobs and residential options. They do not wish to spend hours, days and weeks of their lives behind the steering wheel as their parents and grandparents may have.

M A R C H E T T I C O N S T A N T

… the basic instinct of a territorial animal is to expand its territory (Marchetti, 1994).

Despite the rising rate of public transit provision and preference (Rockefeller Foundation, 2014) there has, globally, been a steady increase and widening use of Single Occupant Vehicles (SOV) for many decades (Newman and Kenworthy, 1999). Historically, the need to travel to work and shopping has always occupied much time, though never so much space as currently required. There are limits to this willingness to travel from one place to another depending on the available modes of transport as after a certain distance and time people will begin to relocate or develop new resource centres. However, we are

Literature Review Page 57 now reaching a critical point in our relationship with SOV travel and its necessities of time and cost to both the personal pocketbook and the wide economy. Yet, this irrationality seems to have an instinctual basis.

Cesare Marchetti’s work has revealed a constant which holds that people adjust their lives to suit preferred time expenditures, despite the cost, resulting in a classic mismatch between behaviour and economic rationality. He attributes this to an ‘animal instinct’ to have as many resources and opportunities as possible despite the expense and threats to safety.

Personal travel appears to be much more under the control of basic instincts than of economic drives. This may be the reason for the systematic mismatch between the results of cost benefit analysis and the actual behaviour of travellers (Marchetti, 1994).

Marchetti gives an example from Berlin which has changed in response to new transport modes level-of-service delivery and how this shift of time expenditure results, ultimately, in other sites in the periphery gaining access to a new ‘Functional Centre’.

Marchetti describes the ultimate consequences of time management and accessibility as the proper progenitors of polycentric urban forms, with zoning facilitating rather than predicting the outcome.

Reducing the access to the geometric center, for example, through zoning, can displace the functional center elsewhere, for example, outside the city.

Shopping centers are a typical consequence of poor transportation toward the center of the city (Marchetti, 1994).

Marchetti’s conclusion is that:

Cars make all the difference. As they have a speed of 6 or 7 times greater than a pedestrian, they expand daily connected space 6 or 7 times in linear terms, or about 50 times in area (Marchetti, 1994).

Literature Review Page 58 Figure 9 City Dimensions in Kilometres due to Dominant Transport Services

SOURCE:MARCHETTI (MARCHETTI,1994), ADAPTED BY THE AUTHOR IN 2013.

The consequence of this expansion of the city by automobile access, according to the theory of Marchetti’s Constant, is that most cities work until they reach an hour’s trip time length after which the residents reconsider their mode choices, land-use options and manner of compacting or dispersing the populations and jobs.

The Marchetti Constant explains how cities throughout history have functioned on the basis of an average one hour per day travel-time budget…. It can be used to explain why walking cities in history were just 5 to 8 kilometres in diameter, transit cities could spread to 20 to 30 kilometres, and automobile cities could spread to 50 to 60 kilometres. Due to the different speeds of walking, transit, and cars, these cities, regardless of physical size, were all “one hour wide” in diameter. Large urban areas today are combinations of these city types – with most journeys being within that

“one hour-wide” locus (Newman & Kenworthy, 2006).

Overcoming automobile dependence thus becomes a question of whether people can access the amenities of a city without a car. In particular for an urban center, it becomes whether the time available for car travel is less than the time it would take to access the urban center using a bike, walking, or riding public transit (Newman & Kenworthy, 2006).

SOV travel now often requires more than the one hour of travel in many cities and, when all trips taken in aggregate are considered, this becomes a very large drain on the

Literature Review Page 59 productivity of the individual, household, city and nation. The hour, or even hours, of time spent daily in commuting replaces time better spent being productive. When added to the costs of owning, operating, storing and repairing the automobile one can figure a high dollar value which could go towards other capital costs in the household or nation. There is even evidence now that divorce rates can be linked to the extra time spent commuting (Committee for Perth, 2014).

A trend towards reduced driving has been measured in the some parts of the OECD and a historic pattern in preferred transport trip time uncovered by Marchetti. How are these relevant to transitioning a city or urban region towards being Transit Oriented?