Confessions of a Recovering Engineer: Transportation for a Strong Town

by Charles L. Marohn Jr.

That night Sagrario Gonzalez made fateful decisions about how to navigate an environment where her existence was, at best, an afterthought, and at worst, a nuisance. The options she had available to her were the result of the underlying values applied to the design of State Street — values reflected in similar environments across North America and wherever around the world American design practices are being emulated.

The injuries and deaths, the destruction of wealth and stagnating of neighborhoods, the unfathomable backlog of maintenance costs with which most American cities struggle, are all a byproduct of the values at the heart of traffic engineering. Addressing the damage requires addressing the values, but you cannot address something that you deny even exists. The underlying values of the transportation system are not the American public's values. They are not even human values. They are values unique to a profession that has been empowered with reshaping an entire continent around a new, experimental idea of how to build human habitat.

Coming out of the Great Depression and World War II, the United States desperately needed a program that would keep the economy going. While the war had created jobs and economic output, demobilization threatened to shift the economy right back into depression. The redirection of American industry and capital from war-making into suburbanization created a kinetic growth machine that fueled a postwar boom. We built a new version of America, one centered around the automobile, transforming an entire continent in a generation. Traffic engineers were tasked with making transportation in this newly imagined approach work. To do that, they needed to standardize nearly every component of this system so that it could be recreated, at scale and with urgency, across a vast continent. It is difficult to overstate how monumental an undertaking this was, nor how astounding their success was in accomplishing it.

In the decades immediately after World War II, increased mobility was driving economic growth. Whether it was families living in new housing in the suburbs, the ability of employees to switch jobs more easily, or the capacity for farmers, loggers, and miners to get their materials to distant markets, the fact that Americans could reach more places in less time provided accelerating levels of prosperity. This notion became a self-evident truth embedded within the traffic engineering profession. Out of it sprung many beliefs that are now orthodoxy.

Today, the American transportation system is fully mature. We finished building the interstate system over four decades ago. The easy mobility gains have long been tapped. We are now left almost exclusively with expensive modifications that provide comparably modest changes in travel time, a theoretical benefit that is quickly denuded by shifting traffic patterns. To the extent that it once was, designing for speed is no longer a proxy for increasing mobility.

Traffic engineers are a critical part of designing transportation systems, but the values of the public need to dominate decision-making. Value decisions need to be stripped out of the design process and given over to nonprofessionals, preferably elected officials and the people living within the community— those directly affected by the design.

The burden and responsibility of making value decisions should not rest with technical professionals. Traffic engineers are incapable of representing the complexity of human experience that needs to be considered in a street design. That is especially true when industry orthodoxy is adhered to. This is not so much a statement on the engineering profession as it is an acknowledgment that city streets are the frameworks of human habitat, a complex-adaptive environment that must harmonize many competing interests.

Roads and streets are yin and yang for city building. They are at cross purposes and antithetical to each other, but both are necessary for ultimate success. We must have great roads that provide high-speed connections between productive places, places that build wealth and prosperity. We must also have great streets that produce enough wealth not only to sustain themselves, but also to fund a proportionate share of the roads that connect them to other productive places. Degrading roads to make them more street-like, or degrading streets to make them more road-like, reduces the overall value provided by the transportation system.

Stroads squander community wealth. They are significantly more expensive to build than a street. For the level of investment, they have a comparably poor financial return and fail to provide a meaningful level of mobility. Yet, the financial impact is far from the only price paid for building stroads. Stroads are the most dangerous environment we routinely build in our cities. If we applied a fraction of the level of scrutiny to their design that we have to the design of such items as baby carriers, lawn mowers, or beach toys, we would have made radical reforms decades ago. Thousands of people die each year on stroads, with countless more maimed and permanently injured. This happens for reasons that are not difficult to discern.

While doing engineering and planning work with communities, I have had an opportunity to discuss with public officials, technical professionals, and other interested parties exactly what they consider to be their most important roads. The answer always centers around commuters, people who do not live within the core of the city but nevertheless drive into the city routinely for work or pleasure. I have struggled to understand this mindset, especially since these planning efforts typically involve people who live within the city and are not commuters. What is it about these magic people who live outside the city that makes people within the city's neighborhoods agree to diminish their own wealth and prosperity so as to accommodate the commuter’s expectations for driving comfort?

Older neighborhoods financially outperform newer neighborhoods. This is especially true when the older neighborhoods are pre-1930 and newer neighborhoods are post-1950. Blight is not an indicator of financial productivity. Some of the most financially productive neighborhoods are also the most blighted. While there are exceptions for highly gentrified areas, poorer neighborhoods tend to financially outperform wealthier neighborhoods. For cities with a traditional neighborhood core, the closer to the core, the higher the level of financial productivity. The more stories a building has, the greater its financial productivity tends to be. The more reliant on the automobile a development pattern is, the less financially productive it tends to be. The traditional development pattern — even when blighted and occupied by the poorest people in our communities — is financially more productive than our post-war neighborhoods, regardless of their condition. Across North America, our poor neighborhoods tend to subsidize our wealthy neighborhoods. The only places this doesn't hold true are communities where the poor have been displaced out to the edge.

Building stable, long-term wealth requires an ongoing, incremental renewal process driven by positive feedback loops. Neighborhoods need to redevelop naturally over time in order to become more intense and valuable as they mature. That cycle is driven by a feedback loop of rising land values.

Single-family homes add garage apartments or convert into duplexes. Duplexes are redeveloped to become fourplex units. Commercial buildings are subdivided to allow more tenants. Gaps are filled in. Space is used more productively. The key is to create this feedback loop over a broad area. Freeze neighborhoods in place with zoning and regulation, and rising land values will merely displace existing residents, creating pockets of affluence in a pool of stagnation and decline. Grow neighborhoods in large leaps instead of incrementally and it will crowd out most investments, causing the same mix of dislocation, stagnation, and decline, while landowners and speculators wait for the big payoff from the out-of-town developer.

In the work that Urban3 has done modeling the financial productivity of different places, there is one correlation that stands out above all others. Wherever development patterns are most productive, wherever the highest value per acre is measured, those are the places where people will be found outside of a motor vehicle. Where humans are found in their habitat, those are the places building the greatest amount of community wealth. The more people who are consistently found, the more productive a place is likely to be.

People often say that they are “stuck in traffic,” as if their vehicle is somehow not a literal part of the traffic in which they are stuck. They are not stuck in traffic; they are traffic. In no other condition of crowding do we entertain this degree of egoism. Nobody goes to Disneyworld and is baffled as to why the lines are so long, begrudging the others who have chosen to visit at the same time. We do not attend a popular movie or board an airplane and experience bewilderment by a desire of other humans to share the same experience simultaneously. Yet when it comes to traffic congestion, the greater the levels of delay, the more we struggle to comprehend just how it came to be and, more perplexingly, what could possibly be done to rid us of this scourge.

The only way to respond to traffic congestion is by creating local alternatives to distant trips. Increases in traffic congestion increase demand for local alternatives. Instead of fighting congestion, we need to embrace it. We need to recognize it for what it is — pent-up demand — and use it to create wealth and prosperity within our cities. Cities that deny requests to build a new duplex or corner store because of concerns with traffic have things backward. Local leaders should never deny a new apartment building or a new neighborhood restaurant because they may increase traffic congestion. It is traffic congestion that requires us to build more and more local destinations.

Traffic signals are only necessary because of the speed of traffic. If traffic moved slower, say a neighborhood-friendly speed of 10 or 15 miles per hour, traffic signals would become largely unnecessary. Here is the maddening part: If traffic could flow freely at neighborhood speeds with no traffic signals and red lights to impede it, if people could navigate along city streets at 10 to 15 miles per hour — speeds that might result in a fender bender but rarely a fatality or serious injury — most people would arrive at their destination quicker.

Traffic signals provide drivers with the privilege of driving at dangerous speeds when they are afforded a green light and it is their turn to proceed. In exchange, drivers accept longer delays and generally increased travel times due to red lights, not to mention a dramatic increase of serious injury and death, than they would otherwise experience if they were willing to travel at slower speeds.

One of the goals of you sitting at a red light is to create a cluster of traffic congestion — multiple vehicles that can travel as a group — with the space between groups being used by drivers who need to make turning movements. This is often difficult to perceive when one is driving, but it becomes really obvious when a person views it while on foot. Traffic signals are used to create traffic congestion so that there can be gaps in the traffic flow. There is a certain absurdity that keeps recurring, especially when engineers and traffic planners speak of this approach as efficient. The higher the speed, the larger the gaps that are necessary to facilitate turning movements. The larger the gaps that are necessary, the longer the red-light delays must be. The longer the delay at red lights, the more congestion created and the longer it takes to get to where you are going.

With the virus-induced drop in traffic volume, what is being revealed is the incredible level of overengineering and unsafe design that occurs throughout our entire transportation system. Remove the traffic congestion that routinely thwarts high speeds and drivers naturally feel empowered to utilize the full capabilities that have been engineered for them. Speeds go up, and so does the rate of fatalities.

Traffic signals do not improve the efficiency of transportation systems. They do the opposite, creating environments where drivers can either travel at dangerous speeds (green light) or must be stationary (red light). The result is a lower average travel speed, unnecessary and excessive delays, and more dangerous trips. The result of traffic signals is an environment of aggression, where a green light licenses a driver to take ownership of public space to the exclusion of others. This is an inhuman approach that, on our streets, reduces the financial productivity and wealth-building capacity of cities. Reducing street speeds can increase traffic flow and reduce travel time for most trips, especially when traffic signals are replaced with continuous flow intersections. There is little to no need to create gaps in traffic flow when speeds are low.

The postwar American development model positions local governments at the bottom of a food chain of governments. In response to cash incentives, cities have allowed themselves to become the de facto implementation branch of state and federal policy. Instead of focusing on the urgent needs of their residents, municipal bureaucracies and local power centers orient around the capital flows that come out of Washington, D.C., Wall Street, and the various state capitals. With transportation funding being the largest, most liquid, and most flexible source of capital, a disproportionate number of local problems are examined through the prism of transportation. This has had a profoundly distorting effect on the way local governments prioritize their time and resources.

The key to understanding the incoherence of the auto-centric libertarian is to recognize that they equate the automobile with individual freedom. In that mindset, when the government spends money increasing the amount people drive, they are simultaneously increasing individual freedom, which in their eyes is the primary role of government. They will join in condemning boondoggle projects and pork-barrel spending, but they accept, and often promote, highway expansion as the proper role of state and federal governments.

Any federal or state level reform would start with a recognition that there is a difference between a road and a street. Roads provide high-speed connections between places and are not used to induce growth or development along a corridor. Streets are platforms for building wealth within a place, which is a hyper-local undertaking. The federal government should fund roads only; there should not be any federal spending building, expanding, or maintaining streets. All supporting documentation, environmental reviews, economic analysis, and the like should reinforce this shift in approach.

Transit in North America is failing because it exists without being tied to any discernible or measurable purpose. Like nearly all postwar transportation investments, it has moved from being a means to an end to being an end unto itself. And as an end, it is an afterthought, an appendage to a dysfunctional auto-based transportation system. If public transit is to have a real purpose it can fulfill, it must separate itself from the underlying auto-based system and stand on its own as the primary wealth accelerator for maturing urban areas.

The aggressive horizontal expansion of cities that would define North American development patterns after World War II was not preordained. Other countries integrated the automobile into existing road and street networks, learning lessons as they went. It was only in the United States, and to a lesser degree in Canada, that government investments in auto-based transportation became the primary mechanism to drive growth, improve social mobility, and codify what would become known as the American Dream.

For these suburban cities, the recipe for short-term success became simple: Have the federal government fund a highway along with the necessary bridges and interchanges. Work with the state to fund frontage roads and an arterial stroad network. Tap into development fees and other growth-related revenue streams to pay for collectors. Then allow national developers and the centralized marketplace to provide everything from shopping malls, big box stores, and fast food to residential homes on cul-de-sacs. The current narrative of this boom is that it built the middle class. The less common, but more accurate, insight is that government investments in transportation made many holders of formerly worthless land into instant millionaires while creating a way for communities to experience growth quickly and the macro economy to generate lots of financial transactions. The overwhelming liabilities to service and maintain all of this infrastructure would start to come due a generation later, but in the short term, especially in those decades immediately after the Second World War, it was seemingly a golden age.

The proper role of transit is as a wealth accelerator for local communities. The purpose of investments in transit is to support broad-based wealth creation within a city. Unlike auto-based transportation investments, transit can actually deliver on that purpose, and when it does, also provide many of the other benefits that transit is capable of providing, from a net reduction of carbon emissions to increased social equity and more. Transit is a wealth accelerator when it is used in support of productive development patterns and is deployed to function either as a road or a street. Successful transit requires successful places, so if you desire transit, you must focus on building a productive place, somewhere where people want to be outside of an automobile.

transit is the only way to overcome the geometric space limitations of the street while still building wealth. In an auto-oriented model, the more cars that are there, the more space that must be given over to accommodating those vehicles. That means parking lots instead of destinations, driving lanes instead of sidewalks, which is the opposite of wealth-building. Auto-based development effectively puts a cap on the success of a place, a physical limitation for how many people can be in one place at one time and, subsequently, how much investment can occur. Transit removes that cap. If the buses on The Loop are too full at 10-minute intervals, then surge to 5-minute intervals. If there is even more demand, make one of the street lanes bus-only. Widen the sidewalks and then allow buildings to expand and adapt, using the success of human congestion to drive investment. Eventually, the positive feedback loops of wealth creation will accelerate the shift from automobiles to higher levels of transit intensity until all that is left on the street from a transportation standpoint is people on foot served by fantastic transit. That will be a ridiculously productive place full of people deeply satisfied by the experience.

While the technology is impressive, recognize that the only difference between a self-driving vehicle and a taxi is the driver. There are instances where replacing the driver with a computer can bring about significant savings — long-haul truckers and bus drivers being two obvious examples — but the single-occupancy vehicle commuting into the office is not one of them. The idea that people will pay thousands of dollars for the novelty of a computer driving their vehicle so that they can watch a movie, read a book, or catch up on their email seems more hype than reality. The modest shift from driver to computer bringing sprawl, pollution, and congestion to a halt also seems more fantasy than reality. The idea that cars will park themselves in remote locations to be summoned when needed is nice in theory but does not seem likely to reduce congestion or even passenger stress.

If we want to keep police officers and the public safe while reducing the number of negative interactions with law enforcement, and if we desire a country where the rules not only matter but their enforcement is fair and equitably applied, then we need to end the routine traffic stop.

There is entire list of technical violations that should never meet the threshold for a traffic stop. Driving without a seatbelt, a busted taillight, expired registration, failure to come to a complete stop, modest levels of speeding, and a long list of other violations of the law do not rise to the level of requiring immediate police contact. These infractions need to be enforced, but that enforcement should happen electronically without direct contact. With the number of cameras and the amount of electronics in a typical police cruiser, it would be a modest exercise to establish a system for officers to document verbally the infraction and then send whatever video they have to a clerk who can issue the citation. The documentation can be appended to a file that could be reviewed by a judge should the citation be challenged.

While there are many great individuals who are engineers and transportation professionals, I have found the internal dialogue of the profession to be stuck in a place of comfortable tension for a long time. There is comfort in the sense that those working on transportation projects have a degree of credibility and prestige earned during the highway-building era, privilege that is kept alive by established bureaucracies and large budgets. The tension comes from a growing realization that the golden age of massive engineering projects has passed, and what is left is an unfulfilled promise of prosperity now encumbered by decades of accrued maintenance liabilities. Engineers two generations ago inspired a nation by building interstates across a continent, constructing landscape-transforming dams, and erecting iconic bridges. Today's engineers are simply asked to maintain it all, a task far more challenging yet much less glamorous.

High-speed traffic combined with stopped and turning traffic is a guaranteed recipe for tragedy. What happened that day wasn't an accident. Accidents are random and not foreseeable. What happened that day was the statistically inevitable outcome of that place. Of that design. Of rolling the dice over and over and over hundreds of times a day until the inevitable straight flush of tragedy poured out of the cup.

I am certain that our descendants will be bewildered by the fact that modern Americans accept a lot of unnecessary suffering, injury, and death as part of a normal life. That we do it in service of an approach that gains us so little for all our efforts will only add to their puzzlement. Vehicle speed and traffic volume are not values that transcend time. We abhor the slavery and inhumane conditions of ancient Egypt, Greece, or Rome, but appreciate that their sacrifices were made producing timeless pyramids, monuments, and temples. For what particular greatness are we sacrificing our people? The misperception of a few saved seconds? To save ourselves a short walk? For the chance at a drive-through hamburger? This is senseless, beneath any nation that considers itself great, even if were not so destructive.

When we mix high-speed cars with stopping and turning traffic, it is only a matter of time until people get killed. That is an undeniably true statement that confronts every transportation professional who designs such environments. The inevitability of death and suffering cannot be explained away by blaming drivers for being human. Yet that is what we do. We wring our hands and wish people would drive more safely. We put our faith in better technology and more enforcement because that kind of faith provides us comfort. That kind of faith absolves us. That kind of faith bridges lament to empathy, reconciling any lingering feelings of urgency with the promise of a more hopeful future.