Automobiles and Pedestrians
Transportation and Land Use
Transportation and urban land use are closely linked. Developing the use of a parcel of land leads to increased activity. This increased activity creates a need for transportation to service it. However, this increased accessibility encourages further development, which brings more activity which requires additional transportation. One directly affects the other, whether at a macro scale (whole urban areas) or micro scale (single buildings). Thus, development (land use) and transportation feed off each other, and create a snowball effect where an increase in one leads to an increase in the other.One of the reasons our cities have sprawled into the countryside, as in no other country of the world, is that we have been willing to build the transportation systems (almost exclusively roads) to allow virtually unlimited development. An intense example of this phenomenon is 28th Street in Grand Rapids, Michigan. Build along what was at the time the southern fringe of the city, 28th Street was originally built as a by-pass route to relieve traffic congestion within the city. However, because of its easy accessibility 28th Street became the most desireable location for new commercial development. It quickly changed from an easy bypass route to the most congested corridor in Grand Rapids, and one of the slowest moving four-lane roads in the state. 28th Street is now so overloaded it is functionally obsolete. The transportation system brought in increased land use, and has now resulted in the need for additional transportation solutions.
One of the major problems is that traffic engineers solve existing problems, without understanding the land use implications of new roads. To better plan they should understand the principle of "latent demand." Latent demand simply means that if more roads are built, people will drive more; they will take an increased number of trips until a certain level of traffic congestion is reached. Based on this principle, it should be assumed that a city cannot build its way out of congestion, for as easier routes are built land use will intensify and drivers will drive more until congestion is again reached. As presented by planner Andres Duany, to truly solve the traffic problem we must reshape our cities in a way where the design of land use and transportation systems reaches an acceptable balance. Some concepts are presented below to encourage such a rethinking.
The importance of traffic to a downtown
One element of downtown planning that is largely counter-intuitive is the role traffic plays. It is now becoming obvious to a few downtown planners that traffic is not something that should be handled efficiently in a city center, but instead should be designed to be inefficient. Traffic engineers have traditionally designed traffic systems, and their approach to downtown routing was the same as in all other sections of the urbanized areaÑhave traffic travel as fast as possible through an area. This approach led to street widenings, turning lanes, and one-way street systems. Yet the downtown can suffer from this approach, for traffic should be encouraged to slow down and interact with the commercial area. It is good for drivers to be driving through slowly looking for a parking place, for they create vitality on the street just as do pedestrians."If you start looking, you start realizing that, gee, if you created less traffic flow, slower vehicles, you create more of a community and you increase the perception of safety and security. The biggest, easiest thing to do is go from through traffic to angle parking. It changes the whole character and attitude about a street. People are going to be backing in and out, which traffic engineers call 'friction,' and friction in their eyes is bad. To us, friction is good. More people are looking around and they're cautious, and they see people and say hello to them."1
1 Martin Gottlieb. 1993. "Conversations/Fred Kent. One Who Would Like to See Most Architects Hit the Road." The New York Times. March 28, 1993.
2 Inland Architect. July/August 1989. pp. 53-54.
