As I’m driving home from work I come to the usual 2 intersections where, every day around the hours of 5 o’clock rush hour, I yield to the traffic guards at each intersection whom essentially serve the purpose of a traffic light. Oftentimes they’re out there in the rain and cold, and after 2 years of taking the same route home, I’ve come to feel almost a sweet recognition for the same folks who are out there every day to wave me through.
One day on the way home from work, after waving a thanks to my friendly neighborhood traffic guards, I begin to wonder about the economics of installing a traffic light vs. hiring these traffic guards to stand out there every day. Sure, there would be a high initial cost of installing a traffic light, but… purely from a budgetary standpoint, I imagine that eventually the traffic light must surely be cheaper over time, right?
Now, please humor me for a moment- Based on a quick google search, installing a traffic light costs $250,000 in initial costs, with an $8,000 annual routine maintenance fee; compared to my estimates of ~$25,000/year to hire these traffic guards1. A quick back of the envelope calculation suggests that it would take ~14.7 years for the installation of traffic light to pay for itself and begin making more economic sense than hiring these traffic guards on an annual budget-basis. Again, this from a PURELY economic standpoint.
The long-term savings that will begin to occur after ~14.7 years is likely not going to present a strong incentive to residents, city council, and local officials in-and-of itself to invest $250,000 in initial installation costs. I imagine traffic light installation may start to make more sense if investment costs break even within the range of an annual budget, or even forecasted out < several years rather than my estimated 14.7 years. In reality, there are a lot of factors that go into installing a traffic light, and city resources is only one of them. Unless the budget clearly warrants action for the traffic light installation, it’s just not going to happen unless some sense of urgency comes from other factors, for example like neighborhood safety and/or heighted need for traffic management.
Really, my little exercise here is mostly to demonstrate a point that has become very apparent to me while working in science, as it relates to policy and decision-making. The installation of this traffic light in Lexington, MA is really not that important in the scheme of things, but can serve as a symbol for other, much more relevant investments and decision-making at the city, state, and federal levels.
This brings me to my main point: What is the tipping point that may warrant the sense of urgency for an infrastructure investment decision, if economics and this year’s annual budget isn’t it? Unfortunately, many aspects of environmental risk and long-term sustainability do not present clear economic outcomes, and environmental risks or consequences are commonly uncertain and difficult to quantify. As a consequence, decisions including infrastructure investment and other legislation are not always carried out with the appropriate sense of urgency that they deserve. We see this time and again, but all too often as case studies in hindsight, and those cases where we are able to acknowledge as a future or present possible risk somehow just don’t seem that urgent.
We all recall the catastrophic devastation that occurred in Louisiana during hurricane Katrina in 2005. This was an event that could have been prevented by an investment in levies and flood protection system which were known to be a risk and are attributed to fatal engineering flaws in the city’s flood protection system2. Similar risks have been identified as an imminent threat in the California levee system in the San Joaquin river delta today, where levees are very old, decrepit, and leaking. Much of the land resides below seawater, and the scenario poses catastrophic flooding if the levees collapse, which is predicted with a >60% likelihood within the next 50 years 3. Although these threats are real and backed by expert opinion, due to the uncertain time frame and probability of these disasters occurring, levee repair has not been tackled with a high sense of urgency at the state level, likely due to the short-term for budget-projects, which translate to short-sited projects with immediate benefits realized.
We are facing numerous red flags with respect to climate change, that can arguably be tackled at the local, state, and federal levels. Nonetheless, in particular at the federal level the current political administration has done little to address the threat of climate change. Mitigation efforts are not met with the sense of urgency they deserve; driven mostly by industry and supported by non-profits and concerned citizen groups. Challenges remain with respect to quantifying risks and somehow translating them to some kind of unit that can speak to the economics of policy and decision-making and action, or in all too many cases, lack of action. In any case, speaking with experience in climate science research, I have learned that it’s important to not only try to measure the impact of these phenomena, but then to take one step further and determine whether these impacts matter and if so, to make the case that we must invest and act with some sense of urgency. This critical communication between science and policy-makers is a huge gap and area of opportunity.
12 traffic guards for 3 hours per day (workdays only) amounts to ~$25,000/year (assuming the mean $15/hour, according to google).
Heather Throckmorton, PhD 
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