That's a good point, but I don't think I've ever been on a highway more than a year or two old that was that overdesigned - the traffic finds them. An underused urban street can be made into a nice linear park.
As a young engineer, I was working on a master sewer plan for a small city. They were experiencing very rapid growth, but we were directed to design based on the zoning. They had a lot of undeveloped land which had been zoned for fairly dense uses. Based on zoning, they could support a population well over ten times the existing, but even at the rapid growth rate they were experiencing the population would not reach that level for fifty years, and at a more normal growth rate it would take centuries. When I pointed that out to the planning director, he looked at me, mouth agape, for several seconds and then asked "So, you think we have too much residential zoning?" My reply was that we should not be planning massive interceptor sewers to support a population that may never exist, but should plan for flexibility to support what was likely to happen during the life of the facilities we were planning.
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William Forbes MASCE, PE, ME, BCEE
Senior Principal Engineer/Vice President of Engineering
Forensic Analysis & Engineering Corporation
Virginia Beach, Virginia
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Original Message:
Sent: 02-19-2021 02:17 PM
From: Joel Dixon
Subject: Cognitive Biases
How much does our professional cognitive bias influence our practise? Let's take transportation design as an example: We make traffic and population growth projections, often linearly extrapolating a current short-term trend decades into the future. Time and again, after funding massively expensive projects that severely alter the landscape and character a city, we look back and realise that that growth just never materialised. We widen streets and roads with the expectation their expansion is needed now, but after spending millions of dollars of the municipal budget, realise that the growth never came. Or worse, it does come, but decades after we built the infrastructure such that in its first lifecycle it didn't get used.
As a profession, I think we're incredibly biased, especially since we're supposed to be the "experts." But engineering, more often than not, is rule-of-thumb and best practise, not scientific law. (I would argue that the problem solving required to find solutions to unique and interesting engineering situations is one of the aspects that draws us to the field, so this fact is not a negative, but helps keep us interested and engaged in the profession.) Too often, instead of approaching a situation humbly in search of a solution, we turn to a manual and treat it as the Bible, even though most manuals explicitly state that they are just guidelines, not gospel.
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Joel Dixon P.E., M.ASCE
Oklahoma City OK
Original Message:
Sent: 02-08-2021 02:03 PM
From: Mitchell Winkler
Subject: Cognitive Biases
This is a fascinating and I think fun topic and I am hoping others will weigh in with their own experience, particularly as seen or experienced in engineering practice. I first became aware of this topic in the early 1990 when first exposed to the concept of decision quality (a future topic) and in particular the disabling role of anchoring.
As a brief background, the notion of cognitive biases was first identified by Amos Tversky and Daniel Kahneman in work published in the early 1970s. The role cognitive biases play in everyday life has now become far ranging from Behavioral Economics to baseball's Sabermetrics. They are also also making their into engineering, e.g., February's free paper: Value of Information on Resilience Decision-Making in Repeated Disaster Environments.
Examples of cognitive biases - also referred to as heuristics - include:
- Anchoring - Why we tend to rely heavily upon the first piece of information we receive?
- Availability - Why do we tend to think that things that happened recently are more likely to happen again?
- IKEA effect - Why do we place disproportionately high value on things we helped to create?
- Representativeness - Why do we use similarity to gauge statistical probability?
Finally, if you read and liked Michael Lewis' book Moneyball I highly recommend his follow up book the Undoing Project. The provides the why behind former. There's also a nice article from the New Yorker The Two Friends Who Changed How We Think About How We Think that serves as a great intro to the overall subject of cognitive biases.
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Mitch Winkler P.E., M.ASCE
Houston, TX
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