The Eternal Complexities of Time Travel
If you could travel back in time, what would you do? The answer given to the point of banality is to kill Hitler as an infant. Yet, surely this would be a thankless job. Without any knowledge of the atrocities he would beget, you would certainly not enter the canons of history as the savior who prevented the deaths of millions from war and genocide. You would receive no recognition from the men, women, and children who would have come to be murdered by his regime, for no one would have ever known that they were to be in danger. Rather, you would be known only to the locals of a small Austrian town as the scumbag who killed a defenseless child.
Don’t get me wrong; I understand the impulse. Who wouldn’t want to save the lives of countless innocents, recognition be damned? No doubt, you are a selfless individual who would gladly take one for the team. What I have a harder time understanding though is how a great many of us would enthusiastically defy the laws of physics only to be sent to the gallows shortly thereafter, while paying so little attention to actions we can take in the present which will assuredly prevent deaths of the more quotidian variety in our own future.
We Don’t Know Who Isn’t Dying
At the recent Vision Zero for Cities Symposium, I had the great privilege of briefly chatting with Mary Beth Kelly about this idea. Ms. Kelly is a valiant activist and a founding member of the inspirational Families for Safe Streets. She, like all members of this organization, has tragically lost a loved one to traffic violence. Sadly, the members of this group don’t have the luxury of confronting this issue in the abstract. They have already suffered the very real loss to real violence, yet they remain committed to preventing these tragedies from befalling yet unnamed potential victims. She acknowledged to me the difficulty in conveying the immediacy of this issue to the public without the name, the face, and biography of the future victim. This is the very nature of prevention and why it is such a difficult proposition for humans to fully appreciate regarding all sorts of problems.
Yet, we know that design interventions are saving lives. We don’t know whose lives they are, but there are undoubtedly people alive and well today because because of the physical alterations of our streetscape. Families for Safe Streets was instrumental in persuading the New York State Legislature to allow the City to reduce its default speed limit from 30 to 25 miles per hour. And while such a reduction may be considered insignificant by some, especially those who romanticize reckless driving, we know that the risk of a collision with a pedestrian resulting in a fatality halves within just this five mile an hour range . We know for a fact that since 2005, locations where the New York City Department of Transportation has performed major engineering interventions, fatalities have dropped by a third, more than twice the rate of unaltered locations . We know for a fact that in the five years between 2007 and 2011, total traffic-related injury rates have fallen by 12 to 52 percent on New York streets where bicycle lanes have been installed . We know for a fact that slowing motor vehicles and reducing the exposure of pedestrians and cyclists to them is saving lives and preventing injuries. We know which design techniques engender these improvements. For instance, by repurposing lanes of general traffic to bicycle lanes and wider sidewalks, drivers enter a space that feels less conducive for speeding, and pedestrians crossing the street are exposed to fewer lanes of motor traffic. While research may continue to optimize the benefit of these interventions, the general direction that results in less misery and less suffering is settled science. Anything short of the implementation of these efforts can only originate from a perverse prioritization of vehicular convenience over human life.
Despite knowing that there are most certainly people alive today who would not have been in an alternate universe where these interventions were not implemented, there is no way of knowing who they are. There are no media accounts of the child walking home from school without incident– no obituaries for the cyclist who wasn’t killed by a driver. We cannot read a profile piece on a victim who never was, nor can we analyze the cause of collision that never happened. Yet these anonymous survivors walk among us, unbeknownst even to themselves.
It’s the System, Stupid
It is this anonymity that blinds us to the impact of these interventions. It is far easier to bemoan the installation of a bicycle lane than it is to celebrate the statistically necessary survival of a person who wasn’t killed. The former is a real, concrete entity that you can point your finger at whereas the latter exists only in a fictitious universe of things that could have been. It certainly doesn’t help that our contemporary moral discussion revolves around lazy, individualistic causality.
There is difficulty in reconciling what statistics are able to tell us with the way in which we experience things. All of our experiences necessarily happen at the individual level, because they are of course happening to us– the individual. Consequences result from individual action. Of course this is true, but it is a very limited perspective that robs us of the context in which the actions are happening. The application of statistics is able to give us insight into these systems, but it has no mechanism for assigning specific outcomes to specific individuals. It will strongly suggest what will happen in the generalized sense, but it cannot tell us to whom it will happen.
But when we limit our thinking to only individual actions and consequences, we fail to appreciate incremental changes that occur over a myriad of iterations. We don’t see those subtle environmental forces which make the difference between a motorist driving at 35 miles per hour versus 25 miles per hour. We don’t see the multitude of sensory stimuli that lead a driver to decide whether or not to swerve around a stopped car. And while these behaviors and a surfeit of others may seem inconsequential in an overwhelming majority of the time, the incremental risk they pose manifests itself over millions of repetitions. By altering the context and changing the design cues to curb dangerous behaviors, the probability of that perfect storm of events resulting in a traffic fatality will inevitably decrease. The nature of these collisions and their respective remediations are inherently chaotic and stochastic. Because of this, they cannot satisfy the simple individualistic causality that we tend find more intuitive.
Thinking in terms of probability is indeed fairly counterintuitive, yet we possess the ability to step outside of our intuition and examine the evidence of the larger systems at play. And although we will never know their names, we know that people have celebrated a birthday they wouldn’t have otherwise but for a design element that made our streets more humane. With the actions we take today, we have the ability to determine the future life and death of our fellow human beings. It could be someone you know and love, or it could be someone you’ve never met. Either way we all deserve the right to not have our lives cut tragically short by an unjust system that prioritizes vehicular speed over human life.
 Rosén, E., & Sander, U. (2009). Pedestrian fatality risk as a function of car impact speed. Accident; Analysis and Prevention, 41(3), 536–42. doi:10.1016/j.aap.2009.02.002
 City of New York. (2014) Vision Zero Action Plan.
 Anderson, M. (2014). Four Reasons Pedestrian Injuries Have Plummeted Along Protected Bike Lanes. Streetsblog USA