Car and city

Barrio de Salamanca (4) Parking

Lots with parking space, according to cadastral data

Lots with parking space, according to cadastral data

A neighborhood designed 150 years ago, many buildings from the XIXth century. As a result, scarce parking when compared to other areas. So City Hall decides that there is a need to have parking under some streets and squares (red rectangles; there are in fact more, but they are not rendered on the cadastral files as such). Even if, as in other cases, some areas are not codified under a parking category, overall this dense neighborhood has scarce parking, but it is a real urban core

Biblio (66) Subdividing individual homes in central Île-de-France

biblio 66-division pavillonaire ile de france

 

A new study directed by the Institut d’Amenagement et d’Urbanisme de la Région Île-de-France (the parisian regional planning agency) shows that in this region:

a) In most of the municipalities having experienced urban density increases between 1999 and 2008 there was no increase in land area for housing.

b) 25% of the new home units appeared between 2001 and 2011 came from pre-existing buildings refurbishment.

This has not happened in a uniform way across the regional space, with areas in which high real estate prices have driven a reduction in the number of homes (quite few and of small size), while others (most) have gone the opposite way.

Up until now the impact of these dynamics on individual home urban tissues was not well known. Some 2.000 homes are produced each year by subdividing some 770 individual homes, mainly in low- middle income areas with reasonable services and public transportation. Usually ownership transforms in rent units, to which young families go.

This text addresses something which is, in fact, a historical constant: as cities grow, their tissues usually densify, and now a time has come to see how a regulated urbanism copes with that on a massive scale.

Some can see here a victory for public transportation, as this concentrates growth in well served areas; I think more data is needed to see which part of residential choice is induced by that, but no doubt this is also relevant in a congested area as metro Paris.

The juice

gasolThis happens in two times: you first buy your car, and then it’s up to you to decide how to use that. To make a car all sort of products must trave betwen distant factories, and the car itself must also usually travel a distance to get to you. Then, up to you. If your car is seldom used, a giant SUV can actually spend less than a hybrid… and this can also apply to cities. A pitty that a thing to be seldom used should have gargantuan proportions?

 

On snails and shells

Which are the figures that can show how good a given urban structure is ? it is often heard that urban density is a relevant figure, and it is a reasonable assessment; the floor-area ratio (how many sq m or sq ft you get to stack over a given area) gives an illustrative figure, that can be easily compared between different contexts. But to agree on the thresholds between high, medium and low density is more difficult, as this depends on culture; as etiologists show that the distance a person accepts as a reasonable intimacy area when surrounded by a set of persons varies with culture (in many sparsely populated regions this value is somewhat high, while in overpopulated cities it is rather small, otherwise the underground would not be used…), the threshold for high density can vary even inside a single country. For instance, in Spain some regional planning laws limit the FAR to 1 (ratio of built floor surface to the development zone area), but some as the Basque Country (in which land uses compete for scarce valley plains) or Galicia (with a tradition of dense urban cores) allow much higher values. Even from an environmental point of view, density must be defined taking into account the carrying capacity of the site.

A second figure is also important: the occupation level of the already urbanized and serviced land. An airline whose occupation ratio were to be 50% of the potential tickets would strive to get profits, and the same happens to a city: maintaining the streets has a cost, usually covered by fiscal income, so no residents means a complex situation, as Detroit painfully reminds.

So density is about how many snails you have in a shell (well, usually one…), and occupation level tells how easily the bug can move the shell…

Asphalt snakes

M30 freeway near Avenida de la Albufera, Madrid

M30 freeway near Avenida de la Albufera, Madrid

The western edge of the M30 motorway in Madrid has been buried; but the eastern part remains on surface, and the way in which it has been contorted to integrate the new tunnels  and engineering variances make for a complex geometry in some areas. And probably a missed opportunity in the greening of these “wasted” fringe spaces… (each one can have his say on what is wasted here)

Biblio (44) The guidelines for public space in metropolitan Bordeaux

Biblio 44

The Communauté Urbaine de Bordeaux (a metropolitan governance body), in France, has published a guide on the project of public spaces. The document is to be read with the Guide for Urban Quality and Sustainable Urban Works edited by the same entity. It has two chapters to be considered as recommendations and three that have a normative role.

The general guidelines for urban interventions are:

–           A city of proximity, favoring the neighborhood scale

–           A reinforced quality of urban spaces and heritage

–           Mastering mobility

–           Ensuring economic vitality

–           A greener and better city

The inhabited city is divided in four wide categories, from the core to the outer spaces: the central site, the neighborhoods, the pericentral territory and the peripheral territory. The landscape analysis is also integrated in the definition of the area.

Five hierarchical levels are defined for streets, from local to freeway.

The document has contents on the dimensions of the spaces as much as on the building materials.

biblio44-secc

Rua Gonçalo de Carvalho in Porto Alegre

And now for an internet finding, as I have never put foot in Porto Alegre (or anywhere in Brazil). Here is a rather local street, that has wonderful trees (Tipuana tipu, or rosewood) and an interesting space, with a regular paving for cars and sidewalks with irregular stone slabs which seem nice, at least seen from Google Street View’s car.

According to the blog poavive, these trees have been planted and maintained by the neighbors, and the street is now a listed space, with legal protection.

Conde de Cartagena street, in Madrid. Maples instead of tropical trees, altough also a good vegetal cover, and less stone on the surfaces

Conde de Cartagena street, in Madrid. Maples instead of tropical trees, altough also a good vegetal cover, and less stone on the surfaces

What surprises me, seen from Spain, is that planting and taking care of the trees is assumed by the neighbors. In many countries this is clearly a municipal affair. Looking at google maps I can see there are other streets in Porto Alegre which also have fine trees, as Marqués de Pombal (a little less dense, in fact), but I do not know if it is also due to the neighbors. Even here in Madrid, far from being a tropical city, we have some streets with good trees, albeit less exuberant. I reckon also that sometimes the relevant role of the neighbors is preventing the trees from being logged; after reading the post on the amics arbres- arbres amics blog, it seems this was also the case in Porto Alegre.

The Gran Vía in Madrid

Gran Vía: 1,3 km (slightly less than a mile) of central street cut through central Madrid from 1910. Not unlike Picadilly Circus/Regent street in London, or Times Square in New York

Gran Vía: 1,3 km (slightly less than a mile) of central street cut through central Madrid from 1910. Not unlike Picadilly Circus/Regent street in London, or Times Square in New York

The Gran Vía is to central Madrid, since its inception in 1910, what the boulevards were for Haussmann’s Paris: a large cut through its old urban tissue. But here it is an isolated case. With an irregular plan, it is the moment in which a Spain that had lost the 1898 war against the United States tries to rebuild its image taking America as a reference.

An icon of modernity in the post-war years, since the 1980s it entered in a decay dynamic, which began to be reversed since the late 1990s, in parallel to a sizeable work on the public space. The closure to motor traffic of the Plaza de Callao and the calle Montera allowed an increase of pedestrian spaces, reinforcing the strongest retail area in the city.

Callao in 2009 (left) and in 2006 (right). One of the busiest walkways in Madrid becomes a grand pedestrian esplanade

Callao in 2009 (left) and in 2006 (right). One of the busiest walkways in Madrid becomes a grand pedestrian esplanade

Gran Vía, as seen from the capitol building on a winter day. Cars occupy most of the space, altough walkways are wide (8 meters in many sections)

Gran Vía, as seen from the capitol building on a winter day. Cars occupy most of the space, altough walkways are wide (8 meters in many sections)

Right side of the previous image. Some urban furniture elements are perharps a bit to bulky; besides, Madrid could use a system similar to that of London, with underground entrances integrated into buildings, to free the sidewalks (altough in this case the problem is limited), but it is something quite dificult to do in an existing city.

Right side of the previous image. Some urban furniture elements are perharps a bit to bulky; besides, Madrid could use a system similar to that of London, with underground entrances integrated into buildings, to free the sidewalks (altough in this case the problem is limited), but it is something quite dificult to do in an existing city.

The left part of the wide image. The sidewalk cafes can be seen, as well as the new granite paving and the pedestrian barrier.

The left part of the wide image. The sidewalk cafes can be seen, as well as the new granite paving and the pedestrian barrier.

Biblio (43) Complete streets

biblio 43- complete streets

When I was a little boy, sometimes the grown-ups told me they woke up so early to go to their jobs, that streets were still not in place. The American concept of complete streets makes me think that in some places are still for early risers…

A complete street is, according to the definition by the National Complete Streets Coalition, a street designed to enable safe access for pedestrians, bicyclists, motorists and public transportation users of all ages and abilities.

This blog is written from an European perspective; I do not pretend to know the whole of the 27 states of the Union, but I can talk with some knowledge about the two cases I know best, Spain, Italy and France.

The presence of sidewalks, presented as one of the main elements in the American vision, is universal in urban land (but for some historical areas in which usually pedestrians are dominant), although width, and location of poles and signs, are sometimes quite bad; but sometimes the peripheral areas, which are not urban land in planning, can have homes without sidewalks. In illegal building areas the situation is worse.

Bicycles are not always well integrated in the street, and the situation varies from city to city.

Traffic and pedestrians are not always in a balanced relation, and crossing is dangerous in some places. And some other issues raised by the Americans are also sometimes deficiently addressed.

So, in the end, although the Americans are clearly in a worse shape (low densities help), we also have things to correct here in Europe. And from that perspective, it is interesting to read the “Complete Streets- Local Policy Workbook”, specially for the most “Americanized “ European peripheral areas.

How many cars are moving in the city?

London congestion charge

Why would you want to count the cars in the city? To be able to dimension properly your street traffic lanes, either to enlarge them or to keep them in such a state as not to increase congestion by appealing more traffic, as often is the case in enlargement projects. Usually measures are taken on a limited number of streets which have a structural role and concentrate most of the cars, without deeming relevant the traffic in smaller streets.

But there can also be a clearer incentive: to levy a tax for using the public space, a rare commodity, and so subvention public transportation. This is the policy instituted in London in 2003 with the Congestion Charge. The system works from 07.00 AM to 06.00 PM, Monday to Friday, with some holidays being exempt. There is 90% reduction for residents. The system depends on 197 cameras along the area’s border, integrating a plate reconnaissance software that allows the charging and fining; as vehicles are bulkier and follow more predictable rules when moving, the cameras are more reliable here than to count people. There are similar charging systems in Singapore and Oslo, and despite the problems that prevented a similar option to be enforced in New York, San Francisco is on the way to apply a charging system.

The system has reduced around 30% vehicles accessing central London, according to Transport for London. The company knows how many cars use the system each day, and results are published monthly on http://data.london.gov.uk/datastore/package/vehicles-entering-c-charge-zone-month. The sharp decrease in users from 2011 is due to the removal of the toll in the western extension

camaras congestion london