I am one of those people that gets annoyed when people don’t follow proper escalator etiquette. The etiquette being: stand on the right; walk on the left. Some cities – London and Tokyo come to mind – are draconian about this.
But it turns out that this is not always the best way to optimize throughput. A recent study conducted in London found that during peak periods – such as the morning rush hour – it is actually better for everyone to stand still.
What they found was that when 40-60% of people chose to walk up on the left, maximum throughput was 115 passengers per minute. But when everyone stood still maximum throughput increased to 151 passengers per minute.
The reason for this is that walking takes up more space than staying put on one step. When demand is low, this has no impact on capacity. But as soon as people start slowing down to avoid the set of legs in front of them, a bottleneck occurs and capacity starts to drop.
This is not dissimilar to what happens in traffic jams. Imagine if during peak periods all of the cars could separate themselves by only a few inches and travel at exactly the same (slow) speed. That’s not going to happen until self-driving cars hit the road, but it would be more efficient than the current chaos of distracted drivers starting and stopping.
All of this being said, since this finding only applies during very busy times, I plan to continue being annoyed when proper escalator etiquette is not followed.
the traffic jam by Phoebe Eve on 500px
In 1968, Garrett Hardin wrote an article where he coined the term: the tragedy of the commons. Hardin was an American ecologist who was obsessed and concerned with the prospect of human overpopulation.
In his article, the term tragedy of the commons was used to describe a situation where individuals – all acting independently and in their own self-interest – actually end up behaving in a way that is detrimental to the larger group and that negatively impacts some sort of common resource.
Just in case, here’s another definition via Investopedia:
An economic problem in which every individual tries to reap the greatest benefit from a given resource. As the demand for the resource overwhelms the supply, every individual who consumes an additional unit directly harms others who can no longer enjoy the benefits. Generally, the resource of interest is easily available to all individuals.
So what would be an example of a tragedy of the commons?
You may not have thought of it in these terms, but I bet you that everybody reading this blog has experienced one.
I will give you two examples.
1. The first is that of electricity consumption.
In most condominiums, there are two types of ways that electricity gets billed and paid. Either the whole building gets one bill (master metering) or each individual resident gets a bill (submetering).
In the case of master mastering, each resident’s consumption isn’t tracked and so nobody knows who is consuming what. But in the case of submetering, each individual resident only pays for the electricity that they use.
Not surprisingly, the data shows that submetering can cut electricity consumption by 10 to 30%. That’s because it creates a 1:1 relationship between usage and cost. There’s now a strong incentive to conserve.
With master metering, there isn’t a 1:1 relationship between usage and cost. The additional burden/cost of consumption actually gets shared by everyone else in the building. And since each individual is looking to maximize their own benefit, they lose the incentive to conserve. As a whole, this makes the entire group worse off.
2. The second example is that of congestion on public, un-tolled roads.
In most cities, public roads are a resource that is “easily available to all individuals” (to use Investopedia’s terminology). They are basically free. The marginal cost of driving another kilometer to work on a road is basically nothing (other than a bit of gas and some time).
What this does is create a situation where individuals – in their pursuit of maximum individual benefit – start to overload the road. Everybody just wants to get where they need to go and there’s no incentive to conserve the resource (i.e. the road). Once again, the result is that the entire group becomes worse off.
That’s why building more road rarely/never works. You’re simply increasing a resource that is easily available to all individuals. What we should instead be doing is looking at submetering our roads (i.e. pricing our roads). It’s been proven time and time again to reduce road congestion basically overnight.
I had never heard of the term tragedy of the commons before today, but I like it a lot. So the next time you’re stuck somewhere in traffic, you can now scream to yourself: What a tragedy of the commons!