Confessions of a Recovering Engineer. Charles L. Marohn, Jr.

by speed limits and signalized intersections. The turn lanes and wide curb radii make movement easy, yet getting from one building to another often requires lengthy detours, U-turns, and delays. There is a veneer of safety that comes from having plenty of margin for error built into the design, but the complexity of the environment creates an underlying tension that randomly disrupts the comfort.

While engineers have tried, it is impossible to make a stroad safe. State Street in Springfield has one of the highest crash rates in the state of Massachusetts.⁴ The only way to improve safety on a stroad is to convert it into a street or a road.

Stroad Conversion

      In the years following the death of Destiny Gonzalez, there have been other collisions and near-collisions in the same location on State Street. In response, neighborhood activists in Springfield requested that the city install a flashing crosswalk system, one that a person walking could activate to alert drivers that someone is crossing. I am not in favor of this approach as anything more than a temporary measure. While it may improve things somewhat, it reinforces the underlying danger created by the stroad.

      To fix a stroad, there needs to be a decision on whether it should be a street or a road. Do we want this section to be about moving vehicles quickly from one place to another (road) or are we trying to build wealth and productivity within a place (street)? To get out of the stroad zone, we need to improve safety by either increasing or decreasing speed — by changing the design to function as either a street or a road.

      State Street should not be converted to a road, but consider what would need to happen if that were the decision. To go from stroad to road, the first thing to be done is to remove access to State Street. That means closing all of the cross streets, dead-ending them before they reach State Street. That would reduce or even eliminate the need for signals because there would be no cross traffic.

      All of the entrances to parking lots and drive-throughs that accessed State Street would also need to be closed. There could be no parking along the road, either, because that would create random start-stop conditions as people back in or pull out of open spaces, a condition that would be extremely dangerous at roadway speeds.

To make State Street a proper road, the sidewalks will need to be removed or, at the very least, a physical barrier would need to be erected between the traveled roadway and any space where people are expected to be present outside of a vehicle. There is no way to build safe space where humans are standing, completely unprotected, just feet away from tons of steel being propelled down the road at lethal speeds. The physics of this are not possible.

      To protect the roadway investment, the city of Springfield would need to use their planning and zoning authority to regulate building along the corridor. Any new development should not undermine the roadway investment or degrade its capacity to move vehicles quickly from one place to another. Anything built along State Street would need to be accessible from some other side street, alley, or property.

      Converting a stroad to a road is a process of simplification. Removing elements of complexity improves safety, allows higher travel speeds, and improves financial productivity by allowing the road to function as a high-speed connection between places. Every American city has miles of stroads that should be converted into roads.

      State Street, especially in the vicinity of the Central Library, is not one of them. This is the core of Springfield. The library is surrounded by blocks of homes, businesses, and civic buildings. This is a place — the exact thing a framework of streets is trying to improve to grow the community's wealth.

      The stroad that is State Street is undermining that wealth, not least by making the area around the library extremely dangerous. To convert State Street from a stroad to a street, the travel speed of the street needs to be reduced to compensate for the complexity of the environment. That means a human speed — something close to 15 and no more than 20 miles per hour.

      The design needs to shift to prioritize people walking, those in wheelchairs, and others who are not within a vehicle. This means traffic passing through becomes a lower priority. That will change the emphasis of intersection design, walkway widths, the placement of trees and vegetation, and any number of other design items necessary to enhance the experience of being in that place.

Since the purpose of the street is to build the community's wealth, the city of Springfield will need to use its community development tools to facilitate investment in the neighborhoods around State Street. The objective is to continually improve the wealth there, a condition closely correlated with the value of the underlying land. As that land value increases, as the place becomes more valuable, a natural redevelopment pressure emerges that attracts investment and generates leaps in financial productivity.

      This is an exercise in adding complexity, something I discussed at length in my book Strong Towns: A Bottom-Up Revolution to Rebuild American Prosperity (Wiley, 2019). Allowing neighborhoods to respond, incrementally, to stress and opportunity is the path to building broad-based, long-term strength and prosperity. Here's what I wrote in Chapter 8 of Strong Towns, “Making Strong Investments”:

      To remove as many distortions as possible, to give neighborhoods a chance to evolve, to build wealth in neighborhoods that is not merely transactional but reflected in the net worth of the people living there, cities must allow, by right, the next increment of intensity throughout all neighborhoods, and they must limit by-right development to only the next increment.

      The goal is to thicken up neighborhoods, to create feedback loops that allow emergent prosperity to build on itself. No neighborhood can be exempt from change, but no neighborhood should experience radical change all at once. This is the prudent discipline we must impose on ourselves.

      Complex systems overwhelmed with resources stop behaving in complex ways. They become merely complicated, losing the feedback mechanisms that drive adaptation. The temptation to work only in bold ways, to embrace instant and comprehensive transformation as a strategy, guarantees eventual atrophy and decline. If our cities are to be truly strong, they must resist the easy path and dedicate themselves to the work.

      Cities can and should grow rapidly where that option is available to them, but that growth needs to be one step at a time, not huge leaps in the dark.

      The environment around State Street is perfectly situated for such a bottom-up revolution. The buildings are underutilized and atrophied, but quite salvageable. The population trends towardimpoverished, but with a high capacity for ingenuity and entrepreneurship. By making State Street a street for the people of Springfield instead of a stroad for commuters, the city can unleash the productive capacity of its citizens and build a prosperous place.

Whether street or road, the city must abandon the stroad approach on State Street and throughout the community. The hierarchical classification system needs to be retired and replaced with an updated understanding of how to make productive transportation investments, as illustrated in Table 2.1.

Table 2.1 Stroad Conversion

Stroad to Street	Stroad to Road
Slow traffic	Limit access
Prioritize people over throughput	Prioritize throughput over access
Build a productive place	Connect productive places
Embrace complexity	Embrace simplicity

      Note