Waiting for Godot

In the first insight on the website, I thought I might look at the most human element of lift design; the wait from button press to car arrival (we consider this concept as a parameter called ‘average waiting time’ when carrying out a lift traffic analysis). Thankfully, unlike the subjects of Beckett’s famous play inferred in the title of this post, the average lift user knows exactly what they are waiting for and where they hope to travel when the lift arrives.

An Instant Age

With most systems, there is an inevitable period of waiting for a response. In a lift system, it is captive to an extent (unless the stairs are an easy option) and normally without distraction or the convenience of even a chair; this facilitates a potentially frustrating experience. Depending on the popularity of the route, the evolution into ‘queue’ can be swift…and without mercy.

The advent of the Information Age in the 1980’s (and the stratospheric technical progress we’ve see seen since) has sharpened the response time of many day to day queries and processes from weeks to hours and from hours to seconds. Remember when checking the price of a flight meant phoning a travel agent? When revising a drawing required a pen and a stencil? Nowadays we live in an instant age, an age where people may not be as prepared to wait as their parents might have been. Even those of you who would consider themselves patient – how long would you persist with a webpage that is too slow to load? Digital marketing studies have shown that latency of as little as 3 seconds is enough to repulse a prospective buyer on an e-commerce site.

Design: One size fits all?

Many of you will know that lift system performance is often targeted and evaluated on the prospective ‘average waiting time’. I’ll be sure to upload a jargon-busting post in the coming days, but in the mean time it’s safe to say this term is pretty self-explanatory. Now it’s hard to argue with waiting time as a design parameter; with the right simulation tools and the relevant expertise it’s a extremely reliable indicator of passenger experience. But it’s harder to see how a one-size-fits-all value for waiting time will suit every building user, and especially in our instant society, whether that value is really fast enough.

Luckily for us as designers, there are some robust industry benchmarks for waiting time that we can work to as a starting point. In the simplest terms, they lie in different ranges depending on building use. Sadly the individual psychology of different passengers can’t really be taken into account within a single building type, but the hope is that the ‘average’ passenger will be content with the design standards set. And what of our instant expectations in an instant age? Well, luckily both our understanding of passenger traffic flow and the speed / complexity of lift equipment has increased dramatically in the last 25 years, allowing us as designers to really minimise those infamous waiting times. Really, no type of building user across market sectors should have to wait (on average) more than 60 seconds, with the highest performing systems realising waiting times of 25 seconds or less.

The Law of Averages

But what does the reader think about this ‘average passenger’, bearing in mind they may or may not have been that passenger this very morning? Let me pose a puzzler; below are 4 types of building user – can you rank them in order of the time they are theoretically prepared to wait for a lift? 1 being the longest waiting time and 4 being the shortest. Answers are, of course, at the end of the article.

  • A student in halls of residence leaving to visit the pub with his pals.
  • A office employee taking the lift to their 17th floor desk on a Monday morning.
  • A hotel guest, returning to their room after a delicious breakfast.
  • A penthouse apartment resident, leaving for work in the morning.

Easy, right?!

Before you read the answers, remember that things are not always as they appear on the surface. For instance, the lift performance in an office building will be focused on productivity and efficient people flow, not how quickly an employee wants to get to work. It is natural that stakeholder requirements for building efficiency will not always fully align with passenger preference, but we should as designers aim to minimise this division where practical.

Mirror Mirror

So in summary, although waiting periods are naturally subjective and inherently linked to passenger psychology, we use our experience and the guidance that exists within our industry to set realistic requirements and deliver a holistic solution for a given scheme. It’s our passion at Vercon to delve deeper; that’s what sets us apart.

One last thing about that ‘average’ passenger. Did you know that they are prepared to wait twice as long for a lift than they usually would if there is a full length mirror in the lift lobby? Now the evidence for this is anecdotal at best, and we cant say we’ve tested the theory, but I would draw your attention to the uptake of the ‘selfie’ and the rising popularity of Instagram; perhaps mirrors have a viable future in the management of passenger psychology after all!

Answers: (Based on CIBSE Guide D: 2015) 1A, 2D, 3C, 4B

Interested in finding out more?