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.

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.