So I'm just going to use this thread to spend some time chatting about queue times because why not.
I used to work at a theme park where it was my job to ensure that the queue times were updated regularly and accurately. I guess you could say it was a job like no other. So it's something I was very interested, and still have a semi-active interest in.
(I'm sure I've made a post on here before which will be similar to this post, so sorry if I bore you with repeat details).
Obviously I can't speak for every park, but I know that many parks do not have any technical system for updating queue times. In other words, it's just "guess and hope for the best". Of course, one can make an educated guess, especially by speaking with guests, experiencing queue times yourself and with experience. But it's a guess all the same. Immediately, it's obvious to see why queue times are inaccurate. Educated guesses will largely be inaccurate.
As toofpikk mentioned, rides teams rarely have direct control over them. There's usually a 'middle-man' figure. One can see the temptation - it helps create a sense of accountability (make sure the queue time is updated), and takes the pressure off when someone working on rides has several other responsibilities too. But equally, it adds another person to the change, and increases the chance for a mistake. It also means that the people working on a ride aren't guaranteed to know what the displayed queue time is.
Another issue with rides teams updating queue times is being able to actually see the queue. The operator of the ride should have full CCTV coverage of the ride and ride area. But there's no need (from a H&S perspective) for the operator to have a view of the queue line if it's not near a ride area. Of course, there should be CCTV coverage for security purposes, but not for the ride operator purpose.
What that means is that a ride operator might not be able to see the full queue. Or they can see the queue in the background of CCTV for the ride. This makes it more difficult to understand how long a queue might be.
To go back to when I had a role updating queue times. I had access to a system which could update the queue times (a very simple interface of each ride having a drop down menu of queue times). I would also regularly walk round the park and check the length of the queues in person. My role involved being a middle man, but a two way middle man. This meant that ride operators could contact me to update queue times, but I could also contact ride operators and inform them when I had updated it as well.
This allowed consistency between different parties about what the queue times were, and meant they were regularly updated.
Systems for updating queue times automatically
There are systems out there which can predict queue times automatically. Some which I am aware of:
1. If a park has an app, and guests allow certain permissions when downloading the app, the app shows the amount of people in certain areas / queues around the park.
2. Headmapping software, which overlays CCTV cameras and counts people going in and out of a queue.
3. The good old fashioned turnstiles
Each of these all have (pretty big) problems though:
1. If people don't download the app, or only have it as 1 between a group, it's pretty damn inaccurate.
2. Such systems require cameras specifically for the software and are surprisingly expensive
3. Easily open to abuse (people spinning the turnstiles for fun)
I'd love to know how somewhere like Efteling manage their queue times. In all of my visits, the queue time estimates have been extremely accurate.
In short though, automatic systems are a good idea in theory, but from what I've heard, harder to implement in practice.
Anyway, moving away from that diversion. Probably the simplest and most cost effective way to move forward for most parks is to just get staff to update the queue times, and ensure this is done frequently and accurately.
I remember reading a research paper which analysed people's behaviour whilst queueing (this was a few years back, and to this day I still cannot find it, so you'll just have to trust me on this). In the UK, if you have groups of people forming a narrow-ish queue, then - on average - you'll find about 11 people every 3m. This is because of the way groups of acquainted people (friends, etc) group together, and then the space they left between their group and a stranger group.
Obviously, that was a study conducted pre-pandemic, so it would be interesting to see how that's changed now, and what the numbers are like in a couple of years' time, for example.
But with that knowledge, one can easily create a way for park staff to understand how long a queue should take from given points. You can measure the length of your queue, determine how many people should be in the queue at given points. Then, knowing the throughput of the ride, you can do some simple maths to calculate a more reasoned educated guess for a queue time.
One can also take that a step further, and if you're able to analyse the changes of the throughput, and even the amount of downtime a ride has on average, you can account for fluctuations too. But that's somewhat more involved.
From experience, something like this can work and can provide accurate queue times. But it requires a certain level of set up, buy in, understanding and drive from many parties, which can be difficult to achieve.
I've rambled a bit here now. And I haven't even touched upon other factors for estimating queue times such as Fast Pass users, numbers of disabled guests, etc. But needless to say, they make estimations more difficult.
A couple more final things though, which admittedly is just reiterating toof's points mostly.
-Towards the ends of shifts, ride staff may not update queue times properly. It happens.
-Covid and social distancing made to much harder to gauge queue times.
-If possible, it's always worth trying to look at a queue and try and use some common sense to see if an advertised queue time is accurate. Not easy when queues are indoors / sprawling. But if you can see a queue, it's a smart idea to exercise that common.
1. Estimating queue times is hard, especially if it's down to ride staff who have many other jobs to do.
1.1. BUT it is possible.
2. Automated systems exist, but your mileage may vary with success.