A few weeks ago I got into a discussion with a friend about urban planning. The topic at hand was related to mass transit, and the concept of Subways vs Commuter Train service. The idea of Subways of course is to easily move from one part of a high density city to another part without impacting surface transportation or requiring a lot of land, which is likely expensive to purchase. Where as the idea of Commuter Train Service is to bring daily commuters in from the suburbs in order to work and do business in the city. The conversation came about as my friend had asked my opinion on a graphic of the TTC subway system with a proposed expansion he was working on for a college project. At some point it was suggested that suburban commuters were not needed in the city, and thus services like the commuter train server were not as desired as subway services. He went on to claim that a city such as Toronto should be completely self sustaining. Okay, I may not have gone to college for urban planning, however studying urban sprawl and such aspects of how cities develop has been a hobby of mine since grade school. So I do have some knowledge on how cities function. Cities do not develop because people 'like the location' or because a town wants to 'become a city'. They develop based on several factors including transportation, access to resources, climate, and the overall need for such a development. Cities don't develop because of the attraction of the city, with the possible exception of Los Angeles. Nor can a city sustain itself with the resources found within that city. No city is self sufficient. All cities rely on outside resources in some form. For example.; Calgary, Alberta is a city which was formed as a Railway town by the CP Railway. It was chosen as a main yard and maintance location on CP's Main line west through the Rockies. The farming and cattle industries, combined with the nearby tourist and resort industries helped contribute to its growth from a simple railway town into a city. Without the railroad, Without the cattle ranches, and wheat fields, and without the nearby resorts in the wilderness, Calgary would not be the city it is today, and it would dwindle and fail quickly if those were suddenly removed from the city. Most cities develop as central marketplaces and gathering places. In my opinion there are 2 major types of cities. The first type is the Industrial City. Focused on production and industries, these cities function through the support and population encouraged by large factories and processing plants. Hamilton, Ontario, or Detroit, MI would be good examples of such a cities. The weak point for these cities is that, if a plant closes, half your population is now unemployed and the need for the services that a large city demands, diminishes as people move away in search of better jobs. The other type of city is the Financial City. Toronto, Ontario, or New York, NY or Chicago, IL are good examples of such. These cities started out as industrial cities, but quickly became centers of finance. While some people would like to elieve that such centers of finance are immune to outside influences, and can survive without them, they would be vastly mistaken. Such cities are often more dependent on outside influences then industrial cities, in that financial cities aralso effected by situations in industrial cities. A strike as a major plant in an industrial city, will likely cause millions or billions of dollars in lost revenue at that plants headquarters in a financial city. Not to mention financial cities usually have a more well established commercial and service industry to serve its more affluent citizens. All of these shops and services depend on goods shipped in from outside the city. I think a lot of the mindset here is that city dwellers get tired of paying taxes toward the city in order to improve infrastructure for commuters to use to come into the city to do business. What a lot of people may not understand however, is that the city also taxes businesses and industries just as it taxes residents. So while a 400 million dollar project to revamp the highways heading into the city may seem like a lot to taxpayers, chances are that money is mostly coming from the industrial and commercial sector. But as usual, city dwellers will think they are the most important people in the world, and they will bitch and complain like they always have. The job of a good urban planner is not to try to trap people in the city, but to encourage growth in the city in all forms, be it residential, commercial, or industrial. As well as ensuring the infrastructure is capable of handling the traffic in and out of the city. Some cities will never develop into high density cities like New York City. New York is a special case in that Manhattan is on an Island, and thus that encouraged high density as everyone wanted to avoid ferries and bridge tolls. Cities like Toronto and Chicago will develop away from their financial centers. Usually remaining fairly high in density along major transportation corridors, but as you move further away, the density will decrease. The cheap land that suburbia provides within an hours commute from major cities, often prevents density from creeping too high in most cities. So in most cases the dream of creating super dense cities is a pipe dream. It will likely not happen. And if urban planners are blindly working towards such a pipe dream without taking into consideration the infrastructure and ability for people to commute in and out of their city, then they are doing more harm them good.