Introduction

At the midpoint of the 20th century, Chicago’s core was walled, rutted, and pitted by transportation. Elevated freeways, the canalized river system, and vast sunken railyards cut horizontal and vertical circulatory fissures through the landscape.

Walk the length of Chicago’s Loop today, and you’ll see a different landscape—the bustling core of a global city. Offices, entertainment, condo towers, and retail. But the fissures are still here, and they hide things.

The fissures hide three entire neighborhoods (Dearborn Park, Central Station, and New Eastside), each no more than two blocks from Millenium Park.

The fissures hide Upper Wacker Drive from the Chicago Riverwalk below, screening the parkland from the dirt and noise of the street.

Collectively, these fissures and their characteristic vertical displacement create a three-level city where spaces can be as secluded as a low-density suburb within walking proximity to some of the most active streets in the world.

To understand this, I will cover two case examples: Dearborn Park and New Eastside. For both of these examples, I will describe how pre-existing fissures and development goals interacted to create the final form of each site.

Dearborn Park

Dearborn Park is a 1970s master-planned neighborhood of townhomes and senior living facilities built on the land of a former railyard in Chicago’s South Loop.  All together, it covers little more than a tenth of a square mile.

Dearborn Park interacts with historic transportation in two ways: First, its existence. New neighborhoods aren’t built every day. How could Dearborn Park be created from scratch in the middle of Chicago? Second, its security. The project of Dearborn Park’s development was moving middle-class families into the South Loop in order to reduce crime. How did the legacy of historic transportation enable this project’s success?

Building a New Neighborhood

New neighborhoods in established cities aren’t built every day, and for good reason: it is nearly impossible to do so. The development of Dearborn Park, a large new neighborhood with starkly different characteristics from the surrounding urban fabric, was only possible because a massive tract of disused land was available for purchase in just the right location. This tract, a former rail yard, made Dearborn Park possible.

The mechanism for this dynamic is described in Stewart Brand’s How Buildings Learn. Brand describes how the practicality of a building typology is influenced by the relationship between the lot size necessary for a typology and the median lot size in a neighborhood. The cost of a new development includes not just the land value, but the legal procedure involved in purchasing each parcel, the cost of paying taxes on the parcel in the interval between purchase and development, and the uncertainty involved in development. Although the land alone should theoretically cost the same, the costs of legal procedure, property taxes, and uncertainty increase when multiple parcels must be assembled (legal costs linearly, taxes and uncertainty costs nonlinearly because the more potential holdouts you have the longer you must wait before development).

Due to these compounding costs, assembling multiple lots can take decades as the developer waits for each individual property owner to place their parcel on the market. Assembling enough contiguous property in a convex shape necessary for a new neighborhood, street plan and all, is practically impossible when it means you must acquire full development rights over hundreds if not thousands of currently occupied individual parcels. Dearborn Park and New Eastside could not have been developed without empty railyards.

Introduction

At the midpoint of the 20th century, Chicago’s core was walled, rutted, and pitted by transportation. Elevated freeways, the canalized river system, and vast sunken railyards cut horizontal and vertical circulatory fissures through the landscape.

Walk the length of Chicago’s Loop today, and you’ll see a different landscape—the bustling core of a global city. Offices, entertainment, condo towers, and retail. But the fissures are still here, and they hide things.

The fissures hide three entire neighborhoods (Dearborn Park, Central Station, and New Eastside), each no more than two blocks from Millenium Park.

The fissures hide Upper Wacker Drive from the Chicago Riverwalk below, screening the parkland from the dirt and noise of the street.

Collectively, these fissures and their characteristic vertical displacement create a three-level city where spaces can be as secluded as a low-density suburb within walking proximity to some of the most active streets in the world.

To understand this, I will cover two case examples: Dearborn Park and New Eastside. For both of these examples, I will describe how pre-existing fissures and development goals interacted to create the final form of each site.

Dearborn Park

Dearborn Park is a 1970s master-planned neighborhood of townhomes and senior living facilities built on the land of a former railyard in Chicago’s South Loop.  All together, it covers little more than a tenth of a square mile.

Dearborn Park interacts with historic transportation in two ways: First, its existence. New neighborhoods aren’t built every day. How could Dearborn Park be created from scratch in the middle of Chicago? Second, its security. The project of Dearborn Park’s development was moving middle-class families into the South Loop in order to reduce crime. How did the legacy of historic transportation enable this project’s success?

Building a New Neighborhood

New neighborhoods in established cities aren’t built every day, and for good reason: it is nearly impossible to do so. The development of Dearborn Park, a large new neighborhood with starkly different characteristics from the surrounding urban fabric, was only possible because a massive tract of disused land was available for purchase in just the right location. This tract, a former rail yard, made Dearborn Park possible.

The mechanism for this dynamic is described in Stewart Brand’s How Buildings Learn. Brand describes how the practicality of a building typology is influenced by the relationship between the lot size necessary for a typology and the median lot size in a neighborhood. The cost of a new development includes not just the land value, but the legal procedure involved in purchasing each parcel, the cost of paying taxes on the parcel in the interval between purchase and development, and the uncertainty involved in development. Although the land alone should theoretically cost the same, the costs of legal procedure, property taxes, and uncertainty increase when multiple parcels must be assembled (legal costs linearly, taxes and uncertainty costs nonlinearly because the more potential holdouts you have the longer you must wait before development).

Due to these compounding costs, assembling multiple lots can take decades as the developer waits for each individual property owner to place their parcel on the market. Assembling enough contiguous property in a convex shape necessary for a new neighborhood, street plan and all, is practically impossible when it means you must acquire full development rights over hundreds if not thousands of currently occupied individual parcels. Dearborn Park and New Eastside could not have been developed without empty railyards.

The Vertical Streetwall

The project of Dearborn Park’s development was moving middle-class families into the South Loop in order to reduce crime; for this project to be successful, the people moving there had to be protected from crime. One way Dearborn Park’s planners attempted to minimize crime was with an external shell that limited vehicle and pedestrian access to the neighborhood. The parcel’s former life as a railyard helped in this task.

Previous structures can leave material legacies of their existence in the built environment long after their demolition. In How Buildings Learn, Brand shows the outline of a Roman amphitheater and how its footprint can still be seen in the city’s property lines and building typologies today. In a similar way, visitors to Dearborn Park today might catch a glimpse of the former railyard’s ghost.

Chicago’s railyards left a legacy of vertical fissures in the landscape because in the railyard days, trains would pass under surrounding streets in order to avoid disrupting local traffic. In the case of Dearborn Park, two adjacent streets (Roosevelt and Clark) were already raised a story above the ground. After the railyard was decommissioned, the elevation of these streets found a new purpose in forming part of the “shell” discussed earlier with no car or pedestrian accessible entrances to the neighborhood a story below.

Dearborn Park Street Grid

New Eastside

New Eastside is a condo tower development at the mouth of the Chicago River with a population density of nearly 70,000 people per square mile. This project transformed vast sunken railyards ringed by Lake Shore Drive and the three-level Wacker Drive into a web of pedestrian-friendly park space amidst a residential density rivaling Manhattan.

The three-level structure of Wacker Drive is as follows: The first (ground) level is a 20mph access road and parking lot. The second level is a pseudo-highway. The third level is an open-air stoplighted street running through Chicago’s Loop.

This three-level road has been leveraged for three purposes. First, the low-traffic ground level serves as a de facto pedestrian underpass between parks on either side of Wacker Drive. Second, the second level pseudo-highway is used as the entrance and exit for associated parking garages, displacing as much regular car traffic as possible away from the pedestrianized first and third levels. Finally, the first and third pedestrianized levels allow condo towers to have direct entrances and exits onto both the ground-level parks and the third-level city street.

Conclusion

The legacy of historic transportation shaped Chicago’s built environment both in its direct effects (development patterns, street layouts) and its indirect effects (how designers leveraged these abnormalities towards their own goals).  By looking at the resulting unique forms, especially Dearborn Park’s pedestrian seclusion and New Eastside’s pedestrian connection, we can imagine new possibilities for high-density urban housing in the future.