Addressing African Cities: Intro. to Urban Planning Today we'll discuss addressing. We'll start out with what is addressing, what is its purpose, and what are some of the techniques to put in place when addressing a city. To address a city is to assign an address to each street, each lot, each parcel, each monument, must be visible on a map, must have an address. The address is a system of geographic references which allows one to be located within a city. A well-known case is the grid street plan of New York, with its streets: 1, 2, 3, 4, 5, up to and beyond 125th St., in Harlem, and then the avenues, which are 1, 2, 3, 4, 5, 6 and 7th, and which continue on like this, so then we have a reference system, where one is at this street and this avenue, at this number, East or West in relation to the avenue, but which allows one to say that this parcel here has this address, Fourth Street, to the East of Fourth Avenue. It's not exactly this system, used in New York, but the same principle, which enables us to know where one is in relation to streets, where one is in relation to avenues, and if one is on the East or West side. So, what is the purpose of addressing? First, it allows us to gather urban information, to have up-to-date and simplified documents. Second, to program investments. Third, to maintain these same investments, which is to say facilities or infrastructure. And, fourth, and this is certainly the most important, it allows for taxation, it allows for the improvement of local resources. We will always say improve local resources, which is clearly about taxation, and in order to tax people, we have to know where they live. And to know where they live, they must have an address. So I would say there is a very clear separation here, on this level here, or here, but we arrive here without addressing, while on the other hand, this part, is not possible unless there is an address or if there is a cadastre, as we'll soon see. So there are two types to capture these resources, these taxes, whether via the cadastre or via addressing. We'll talk now about addressing. What we must realize is that with both the cadastre and addressing we have two types of documents, the first which is a graph, a graphic type, which is a city map, and the second which is a database. We must correspond these to a SIG, as we've seen. For the SIG the two types of documents are at the same time a spatial representation and a database which is connected to this spatial representation. We have the same thing, so we can use the SIG as a tool in addressing, and/or the cadastre. This establishes at the same time spatial data and alphanumeric data. Addressing is a method which allows us to identify roads and buildings, giving each an address, so we have at once a spatial representation, planimetric, in two dimensions, city blocks, parcels with, each time, its own address file. If I were to differentiate between a cadastre and addressing, to the left we have the cadastre, to the right addressing, the cadastral reference and the parcel, parcel 1, 2, 3, or parcel A1, A2, A3, there are many possible systems, but let's go by block, and then, within the block, we'll go by parcel number. Addressing is a different system, where what interests us are the entry points to each parcel, since while we don't know what's going on here, what we do know is that here we are at 15 Something Street, Something Avenue, Something Boulevard, and that we have numbers which mean that it is an address here. We have, perhaps, number 17, or 19, we'll soon see the different ways of city addressing. The cadastre, on the other hand, is an exhaustive inventory of parcels. The address is not longer key, it matters little where the parcel is located, what is important is that one can have a precise idea of the parcel, and particularly the number of square meters it occupies. Since we want to tax based on square meter, the cadastre is a better means since it gives us this information directly. With addressing we have only a part of the information. But the cadastre requires resources, and requires a technical expertise far greater than that of addressing. So we need human as well as technical resources in order to have a cadastre which is current. The problem with the cadastre is that it also must be updated often, while addressing needs it relatively less often. Once you have your address, your address exists and you can, without the need for regular updates, continue based on this address book. The methodology behind addressing is relatively simple, I say relatively because it requires significant human resources, but it requires a global implementation, in three phases, of the addressing plan, First we need a cartographer. We must invent the codes to be used, Next we begin addressing. We must put up signage, put numbers on the doors, placing these different address in a very clear manner in situ, and finally, once this work is finished, we must compile an address book and its database. So we've elaborated here a methodology and an action plan. We've implemented it on the ground, placing signage and door numbers. And then we've created a file of all the addresses, which we've assigned on the ground. This is the method we will use. Which has, at the same time a theoretic part, how we will number the streets, number the doors, and a purely technical part, on the field, where we must place signage and place the numbers and then compile this database, which is, ultimately, our goal. Now, briefly, if I have my city with its main roads, secondary roads, and we'll determine the sectors, which we'll call 1, 2, 3, it doesn't matter. We can go clockwise. Remember that the districts in Paris use numbers which go like this, from one to the next, from the first to the second. And then we have the inner suburb, and the outer suburb. Then once we are at Sector 1, we go back to an address, which will be 1, and then we have a system of streets, we might have a numeration, 1-1, 1-3, 1-5, and then the streets going in the other direction will be 1-2, 1-4, 1-6, and so on. So if I live here, this means that in this house here, this means that I live on Street 1, Sector 1-- No, sorry, Street 6, and then there will be a certain distance from the beginning of the street, we'll explain this is in a moment, but let's assume that I'm 45 meters from the beginning of the street. Here's the type of address I might have. So we determine the methodology, and then we must go to the beginning of each street, place the signage here. Once all this is done, we'll use all the addresses, and all the addresses will give us a database. Different ways of calculating. Different ways of placing the number on the parcel. Now I have my street here, the two sides of the street, and then we determine which is the beginning of the street, which goes in this direction, and then we have a first possibility, which is what we commonly see in Europe, evens on one side, and odds on the other, so we have Door 1, Door 3, Door 5, Door 7. And then on the other side, I'll have 2, 4, 6 or 8. This is how it's done. If I divide one of the two parcels in two, I'll have 6-A, then we'll have 6-B, etc. The other possibility I have would be to, again, from the beginning of the street, which runs in this direction, to count the number of meters and choose, once again, the evens and odds. I am, for example, at 6 meters, at 20, 34, 52 and 64 meters, which makes my parcel number relative to the doors' axes
