Patent Publication Number: US-2023162552-A1

Title: Methods of estimating a throughput of a resource, a length of a queue associated with the resource and/or a wait time of the queue

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a Continuation-In-Part application of U.S. patent application Ser. No. 15/141,780, filed Apr. 28, 2016 and entitled “INTELLIGENT PREDICTION OF QUEUE WAIT TIMES,” which claims the priority benefit of U.S. provisional application No. 62/153,686 filed Apr. 28, 2015 and entitled “System and Method for Predicting Line Wait Times,” each of which is hereby incorporated herein by reference in their entirety. 
     This application is a Continuation-In-Part application of U.S. patent application Ser. No. 17/088,039, filed Nov. 3, 2020 and entitled “QUEUING SYSTEM,” which is a continuation of U.S. patent application Ser. No. U.S. Ser. No. 15/315,712, filed Dec. 1, 2016, which is a National Stage Application of PCT/GB2015/051607, filed Jun. 2, 2015 and entitled “QUEUING SYSTEM,” which claims priority to GB 1409764.6, filed Jun. 2, 2014, all of which are incorporated by reference in their entirety. 
    
    
     FIELD 
     One or more aspects described herein generally concerns analytics pattern processing. More particularly, these aspects concern predicting resource throughput, queue lengths and queue wait times, based on multiple sources of data. 
     BACKGROUND 
     Entertainment and event venues such as theme parks, cruise ships, universities, arenas, concert venues, ski resorts, relaxation resorts, ice rinks, spas, skate parks, and stadiums typically have large numbers of visitors/guests. These venues typically have multiple “points of interest” that correspond to locations of attractions such as restaurants, cafeterias, concession stands, stores, libraries, theme park rides, theatre shows, movies, circus shows, animal shows, or costumes characters. Points of interest may also include locations of restrooms, water fountains, entrances, exits, or crossroads. 
     Due to the large numbers of guests in these various venues, those wishing to visit such points of interest will typically be required to stand in fairly long lines. The wait line for any given point of interest may have different numbers of guests on different days (e.g., weekends versus weekdays) and during different times of day (e.g., mornings versus afternoons). More guests in a line typically translates to a longer wait time unless guest throughput is increased by the entertainment venue. Means for increasing throughput might include operating additional cash registers or increasing overall guest capacity of a particular venue as might occur through making available an increased number of seats or moving furniture to increase floor space. 
     Some entertainment venues currently provide an estimated line wait time to guests. But this wait time is a rough estimate typically determined by venue staff periodically picking a single guest and tracking how long it takes that guest to traverse the line. Though somewhat helpful to new guests entering the line, line conditions may fluctuate during the wait time making the prediction inaccurate. This might occur with a rapid influx of new guests in a relatively short period of time. While staff may react by increasing guest throughput or guest capacity, such reaction is after-the-fact and occurs only once the problem is visibly identified. 
     Such manual wait time estimates are typically only provided for large “main” attractions due to the effort required. As a result, wait times for smaller attractions are often completely unknown to guests. Furthermore, there is no way to predict future wait times (i.e., what will the wait time be in one hour or next Tuesday or on a particular holiday) using manual methods such as these. Thus, there is a need in the art for determining wait times for points of interest in a venue. 
     Queuing systems are employed in various types of situation where multiple users wish to access the same resource or attraction at the same time or as early as possible, including restaurants, amusement park rides, museum or gallery exhibits, service counters or meetings and other similar activities. In such situations, a physical queue is often used. A ticket-based queuing system (a so-called ‘deli-counter’ ticket) is an improvement on this, but still groups all waiting users together. 
     Virtual queues offer benefits to attraction operators and users (also referred to as guests in the context of an amusement park, for instance), since time spent waiting in a physical queue is considered wasted and could be spent on other activities. 
     Where multiple attractions are being managed at the same time, the complexity and costs increase by an order of magnitude, especially when a virtual queuing system is set up for each attraction. Thus, management of guests or users for such queuing systems in a cost-efficient and operationally-efficient way remains a challenge 
     SUMMARY 
     Against this background, a method of estimating a throughput of a resource within a venue is provided. The method comprises: determining, by the server, an operating throughput of the resource; receiving, by the server, event schedule data identifying a plurality of scheduled times corresponding to a plurality of events occurring at the resource and/or nearby points of interest, wherein the events cause the throughput of the resource to deviate from the operating throughput of the resource; and estimating, by the server, a throughput of the resource based on the operating throughput, and the event schedule data. 
     The method may further comprise one or more of: displaying, by the server and via a map user interface of a front-end device, the estimated throughput; sending, by the server, the estimated throughput to one or more of a front-end device and mobile devices corresponding to venue guests; determining, by the server and based on the estimated throughput, an estimated current wait time and sending the estimated current wait time to one or more of a front-end device and mobile devices corresponding to venue guests; determining, by the server and based on the estimated throughput, a time at which a venue guest joining the queue is permitted entry to the resource and automatically sending, to a mobile device corresponding to the venue guest, a notification indicating when the venue guest is permitted entry to the resource; managing, by the server and based on the estimated throughput, a virtual queue, wherein managing the virtual queue comprises automatically sending, to mobile devices corresponding to venue guests included in the virtual queue, notifications indicating when the corresponding venue guests are permitted entry to the resource; and regulating, by the server, access to the resource by one or more venue guests by receiving, from a mobile device corresponding to a venue guest, a request to access the resource, adding the venue guest to a virtual queue associated with the resource, and managing the virtual queue by removing the venue guests from the virtual queue at a rate based on the estimated throughput of the resource. 
     Advantageously, the proposed method may provide a more accurate and reliable method of estimating the throughput of the resource, because a schedule of events that affect throughput is used to predict changes to the operating throughput. This is in contrast to prior art methods, which assume constant throughput and then react to changes only after they have directly affected the throughput. 
     Preferably, determining the operating throughput comprises one or more of: measuring a current throughput of the resource; determining an average throughput of the resource; receiving a theoretical maximum throughput of the resource; and using a model trained with historical throughput data. 
     There are different possible methods for determining the operating throughput. In one method, start with the operational maximum throughput and then account for inefficiencies (both historical and predicted) that cause deviations (shortfalls) of the throughput from the theoretical maximum. For example, if a resource has loading inefficiencies that reduce the throughput by 5% and also tends to operate with 10% empty seats on average (e.g. because users prefer to sit with other users in their group), the operating throughput of the resource may be around 85.5% of the theoretical maximum (0.95×0.9). 
     In an alternative method, the operating throughput is measured directly (e.g. by sensors at the entrance to the resource). The current measured throughput may be the instantaneous throughput (where the throughput varies fairly smoothly) or may be a rolling average of the instantaneous throughput over a predetermined period, to smooth out short-term fluctuations in the instantaneous throughput (e.g. due to loading/unloading times). 
     Preferably, the event schedule data (or the one or more scheduled events) includes one or more of: cleaning or maintenance of the resource; a change in a capacity of the resource; a change in duration of a guest interaction with the resource; a change in staffing levels for the resource; and a start time or end time of a show scheduled at the resource. 
     For example, a change in the capacity of the resource may result from: increasing/decreasing the number of trains/carriages/cars/boats running on a ride, changing a number of seats available (e.g. by adding/removing tables), and/or changing the available space (e.g. by opening/closing an area). 
     The duration of a guest interaction with the resource may be a performance, show or ride running time, for example. 
     A change in staffing levels for the resource may be a result of adding another server to process a queue, for example. 
     The throughput of an attraction may vary considerably if events that are of interest to the guests occur at prearranged times. For example, guests may enter an attraction in large numbers the run up to a start time of a show and leave after the end time. These times can therefore have a big impact on the throughput of the resource. For example, where guests do not enter/exit during a performance, the throughput may be very high for short periods (during changeover) and then low for long periods (when the performance is ongoing). In other examples, guests may enter and exit the attraction during the show and there may be a more even throughput of users. 
     Preferably, estimating the throughput of the resource based on the operating throughput and the event schedule data comprises: extrapolating the operating throughput and adjusting the extrapolated throughput based on the event schedule data. 
     Extrapolating the operating throughput may comprise assuming the current operating throughput remains constant or that the current trend in the operating throughput will continue. Adjusting the extrapolated throughput based on the event schedule data may comprise increasing or decreasing the operating throughput by a certain number or proportion when a capacity, duration or staffing level is changed, or by pausing the throughput for cleaning/maintenance. 
     Preferably, estimating the throughput of the resource based on the operating throughput and the event schedule data comprises: training a throughput model with historic throughput data and estimating the throughput using the throughput model. 
     Historic throughput data may comprise data from previous days. The data may further comprise other parameters for those days that may be correlated with the throughput, such as the time since the resource was last serviced, a capacity/duration of the resource at the time, total guest numbers in the venue, ambient temperature, rainfall, throughput (and queue length) of other resources in the venue, and the like. 
     Preferably, the throughput model is a machine learning model, wherein training the throughput model with the historic throughput data comprises training the throughput model with timestamped throughput data and concurrent data comprising the event schedule data. 
     The concurrent data may influence or be influenced by the throughput, such that correlations between the concurrent data and the throughput may be drawn. As described above, event data may have an impact on the throughput and therefore the concurrent data comprises the event data. Other examples of concurrent data may include: weather data (such as temperature, humidity, wind and/or rainfall); total number of guests in the venue or a sub-area of the venue; queue length (guests may behave differently depending on how long they have been queuing, which can affect throughput); the time since the resource was last serviced; a capacity of the resource; a frequency of a performance at the resource; and/or a duration of the performance. 
     Preferably, the concurrent data further comprises resource state data and/or venue state data. 
     Resource state data may comprise resource capacity (number of trains running), staffing levels, time since last maintenance, and the like. 
     Venue state data may comprise total number of people in the park, ambient temperature, day of the week, and the like. 
     Preferably, the method further comprises: accessing a calendar data store and retrieving one or more scheduled events, which are scheduled in the calendar data store. 
     By storing the calendar of scheduled events in a centrally accessible data store, park management activities may be performed in response to the state of the resources in the venue. For example, if demand for certain resources is greater than predicted, staff may be redistributed, if a ride breaks down unexpectedly, maintenance may be brought forward and maintenance for other resources may be rescheduled. 
     Preferably, the method further comprises: obtaining, from one or more sensors, one or more resource operating parameters; and updating the one or more scheduled events in the calendar data store, based on the one or more resource operating parameters. 
     The sensors may comprise video cameras or beacons used to monitor queue length and/or rate at which users join the queue. Cameras may also be used to monitor whether there are empty seats when the resource is running (resource utilisation efficiency). Sensors can also monitor time taken for resource changeovers, resource running speed, temperature, vibrations, and other operational parameters. 
     Preferably, the one or more resource operating parameters comprise one or more of: a number of users in a physical buffer queue associated with the resource; and a number of unoccupied seats on the resource. 
     The number of users in the queue may be determined by a method described in more detail below. 
     Preferably, updating the one or more scheduled events in the calendar data store based on the resource operating parameters comprises: creating a new scheduled event in the calendar data store; or updating a time at which an existing scheduled event in the calendar data store is scheduled to occur. 
     Updating a scheduled event time may comprise moving the event forwards or backwards in time in order to: influence demand for the resource, and/or affect the throughput of the resource. 
     Demand may be influenced by changing show times at nearby attractions, for example. The throughput of the resource may be affected by rescheduling cleaning or maintenance (e.g. to occur at a time of when there is decreased demand for the resource). 
     A method of estimating a length of a queue is also provided. The queue is associated with a resource within a venue. The method comprises: receiving, from one or more cameras present in the venue, one or more images of the queue; estimating, by a server, a number of venue guests standing in the queue, based on the one or more images of the queue. 
     The method may further comprise one or more of: displaying, by the server and via a map user interface of a front-end device, the estimated number of venue guests in the queue; sending, by the server, the estimated number of venue guests in the queue to one or more of a front-end device and mobile devices corresponding to venue guests; determining, by the server and based on the estimated number of venue guests in the queue, an estimated current wait time and sending the estimated current wait time to one or more of a front-end device and mobile devices corresponding to venue guests; determining, by the server and based on the estimated number of venue guests in the queue, a time at which a venue guest joining the queue is permitted entry to the resource and automatically sending, to a mobile device corresponding to the venue guest, a notification indicating when the venue guest is permitted entry to the resource; managing, by the server and based on the estimated number of venue guests in the queue, a virtual queue, wherein managing the virtual queue comprises automatically sending, to mobile devices corresponding to venue guests included in the virtual queue, notifications indicating when the corresponding venue guests are permitted entry to the resource; and regulating, by the server, access to the resource by one or more venue guests by receiving, from a mobile device corresponding to a venue guest, a request to access the resource, adding the venue guest to a virtual queue associated with the resource, and managing the virtual queue by removing the venue guests from the virtual queue at a rate based on the estimated number of venue guests in the queue. 
     Advantageously, using images of the queue from cameras to estimate the number of venue guests in the of the queue may automatically provide an accurate estimate of the queue length. This may be used by park management software for various purposes, such as calculating wait time, estimating throughputs, and the like. 
     Preferably, estimating the number of venue guests standing in the queue comprises one or more of: comparing the one or more images with one or more references images of a same location captured at a time when there are no venue guests in the queue; applying a mask to the one or more images so that areas of the one or more images that correspond to areas of the venue that do not form part of the queue are excluded when estimating the number of venue guests; and detecting heads of venue guests visible in the one or more images, preferably also determining whether each of the venue guests is standing in the queue. 
     Detecting heads of venue guests may comprise using image processing techniques to recognise user heads in the queue. Image processing techniques may also be used to categorise the heads detected in the image to heads of users queueing for the resource and heads of users that are not queuing for the resource (e.g. because they are queuing for other resources, travelling between resources, resting on benches, and the like). 
     Previous methods may rely on the physical distance covered by the queue, assuming a uniform density of guests to estimate a number guests in the queue. However, this method may be inaccurate because guests do not queue in a uniform density. The queueing density may be affected by weather, as users accumulate in sheltered parts of the queue during rain. Users may also spread out more in the queue in response to news events concerning infectious disease. Such changes in queue density can render previous techniques for estimating queue length inaccurate. The proposed method therefore aims to provide an improved estimate. 
     Preferably, estimating the number of venue guests standing in the queue comprises, for each image: estimating a number of pixels of the image that correspond to venue guests standing in the queue; and applying a weighting to each pixel, based on a gradient mask applied to the image, wherein the gradient mask causes a lower weighting to be applied to pixels corresponding to areas that are closer to a corresponding camera and a higher weighting to pixels corresponding to areas that are further from the corresponding camera, to account for perspective effects in the image. 
     A method of estimating a wait time of a queue associated with a resource within a venue is also provided. The method comprises: estimating a throughput of the resource by a method as described above; estimating a length of the queue by a method as described above; and estimating a current wait time of the queue, based on the number of venue guests in the queue and the throughput of the resource. 
     The method may further comprise one or more of: displaying, by the server and via a map user interface of a front-end device, the estimated current wait time; sending, by the server, the estimated current wait time to one or more of a front-end device and mobile devices corresponding to venue guests; determining, by the server and based on the current wait time, a time at which a venue guest joining the queue is permitted entry to the resource and automatically sending, to a mobile device corresponding to the venue guest, a notification indicating when the venue guest is permitted entry to the resource; managing, by the server and based on the estimated current wait time, a virtual queue, wherein managing the virtual queue comprises automatically sending, to mobile devices corresponding to venue guests included in the virtual queue, notifications indicating when the corresponding venue guests are permitted entry to the resource; and regulating, by the server, access to the resource by one or more venue guests by receiving, from a mobile device corresponding to a venue guest, a request to access the resource, adding the venue guest to a virtual queue associated with the resource, and managing the virtual queue by removing the venue guests from the virtual queue at a rate based on the estimated current wait time. 
     Estimating a throughput of the resource preferably comprises forecasting the future throughput over a predetermined period. This future throughput can be useful for calculating current queue wait times. In other words, if a user joins the queue now, the time it will take for them to reach the front is dependent on the future throughput for the entire time they are in the queue. For example, if a coarse estimate indicates that it will take approximately one hour for a user to reach the front of a queue after joining, it may be useful to forecast the throughput of the resource over the next one or two hours, to provide a more accurate estimate of the wait time of the queue. 
     Alternatively, “estimating” a throughput of the resource may comprise estimating a current throughput of the resource. The estimated current throughput may be an improved estimate (e.g. more accurate), compared to the operating throughput determined via other means. 
     A coarse estimate could be based on a measured length of the queue and/or on historical measurements of wait times (but not accounting for the event schedule data). 
     Moreover, as well as estimating current wait times, future throughputs may also be useful to estimate future wait times. These future wait times may be communicated to users so that they can plan to join the queue at a time when demand is lower. This can result in users spending less time standing in line and therefore more efficiently utilising the resources in the venue. 
     The method may further comprise forecasting a demand of the resource (in other words, predicting a rate at which users will join the queue). Forecasting a demand of the resource may comprise training a model with historical data. 
     Where the wait time and/or forecasted wait time is communicated to the users, the estimated demand of the resource may depend on the forecasted wait time (because users may be unwilling to wait long periods or may select an alternative resource with a shorter wait time). Therefore, a feedback loop may be set up, which may be accounted for when estimating wait times. 
     The method may further comprise: measuring, by the server, a direct wait time of at least one venue guest in the queue, by: receiving, from the one or more cameras, a plurality of timestamped images of the queue and performing facial recognition on the timestamped images; or receiving, from one or more beacons present in the venue, one or more timestamps tracking one or more mobile devices, corresponding to the venue guests, in proximity to the one or more beacons, wherein the current wait time of the queue is further based on historic data comprising the measured direct wait time. 
     The method may further comprise: tracking, by the server and via a satellite navigation system, locations of the one or more mobile devices, corresponding to the venue guests; identifying, by the server, one or more trends in the locations of the mobile devices, based on the event schedule data; inputting, into a machine learning model, one or more of: the estimated current wait time, the measured direct wait time, the tracked locations of the plurality of mobile devices, the event schedule data, and the historic data; and wherein estimating the current wait time of the queue, comprises generating, by the machine learning model, an estimated wait time. 
     The method may further comprise: displaying, by the server and via a map user interface of a front-end device, the estimated current wait time. 
     The method may further comprise regulating access to the resource by the plurality of venue guests by: receiving, from a mobile device corresponding to a venue guest, a request to access the resource; adding the venue guest to a virtual queue associated with the resource; managing the virtual queue by removing venue guests from the virtual queue at a rate, based on the estimated throughput of the resource and/or the length of the queue. 
     The method may further comprise: controlling access to the resource such that a venue guest presenting a mobile device is allowed to access the resource only after being removed from the front of the virtual queue, no other access to the resource being permitted. 
     A server configured to perform a method as described above is also provided. 
     Computer software is also provided. The computer software comprises instructions that, when executed by a processor of a computing system, causes the computing system to perform a method as described above. 
     Some further non-limiting examples are set out below. 
     A first further example involves a method for queue wait time estimation, and includes receiving mobile device location data associated with a plurality of guest mobile devices corresponding to a plurality of venue guests within a venue. The method also includes receiving event schedule data corresponding to schedules associated with a plurality of points of interest located within the venue. The method also includes generating an estimated wait time based at least on the received mobile device location data and the received event schedule data, the estimated wait time corresponding to a first point of interest of the plurality of points of interest. The method also includes transmitting a wait time dataset identifying the estimated wait time to a front-end device, thereby displaying the estimated wait time via the front-end device. 
     The first point of interest may be one of an amusement park ride, a restaurant, a cafeteria, a restroom, a concession stand, a store, a library, a theme park ride, a theatre stage, a movie theater, a circus stage, an animal display showing, or some combination thereof. 
     The estimated wait time may be a prediction of a time that a guest would currently wait before entering the first point of interest. 
     The estimated wait time may be a prediction of a time that a guest would wait at a predetermined future time before entering the first point of interest. 
     The method may further comprise receiving network traffic data. Generating the estimated wait time may be further based on the received network traffic data. 
     The method may further comprise receiving entitlement redemption data. 
     Generating the estimated wait time may be further based on the received entitlement redemption data. 
     The method may further comprising receiving weather data. Generating the estimated wait time may be further based on the received weather data. 
     The method may further comprise generating a plurality of additional estimated wait times at predetermined intervals from each other. 
     The method may further comprise generating a graph charting the estimated wait time and the plurality of additional estimated wait times. 
     The front-end device may be a guest mobile device corresponding to a venue guest. 
     The front-end device may be a staff device corresponding to a venue staff member. 
     The method may further comprise generating a map user interface that identifies the estimated wait time at a location on a map corresponding to a location of the first point of interest. 
     The map may be distorted so that a first region is drawn at a first scale and a second region is drawn at a second scale. 
     The map may include a third region between the first region and the second region, the third region having a gradient scale between the first scale and the second scale. 
     The method may further comprise generating a list user interface that identifies the estimated wait time next to a name corresponding to the first point of interest. The name may be one of a plurality of names within a list of the list user interface. 
     Generating an estimated wait time may be performed using at least one of a Bayesian algorithm, a nearest-neighbor algorithm, an alternating squares algorithm, a neural network, or some combination thereof. 
     A second further example concerns a system for queue wait time estimation that includes a communication transceiver receiving mobile device location data and event schedule data. The mobile device location data is associated with a plurality of guest mobile devices corresponding to a plurality of venue guests within a venue. The event schedule data corresponds to schedules associated with a plurality of points of interest located within the venue. The system also includes a memory. The system also includes a processor coupled to the memory and to the communication transceiver. Execution of instructions stored in the memory by the processor performs system operations. The system operations include generating an estimated wait time based at least on the received mobile device location data and the received event schedule data, the estimated wait time corresponding to a first point of interest of the plurality of points of interest. The system operations also include triggering transmission of a wait time dataset to a front-end device via the communication transceiver, the wait time dataset identifying the estimated wait time, thereby displaying the estimated wait time via the front-end device 
     The communication transceiver may further receive network traffic data. Generating the estimated wait time may be further based on the received network traffic data. 
     The communication transceiver may further receive entitlement redemption data. Generating the estimated wait time may be further based on the received entitlement redemption data. 
     20. A non-transitory computer-readable storage medium, having embodied thereon a program executable by a processor to perform a method for estimating queue wait time, the method comprising: receiving mobile device location data associated with a plurality of guest mobile devices corresponding to a plurality of venue guests within a venue; receiving event schedule data corresponding to schedules associated with a plurality of points of interest located within the venue; generating an estimated wait time based at least on the received mobile device location data and the received event schedule data, the estimated wait time corresponding to a first point of interest of the plurality of points of interest; and transmitting a wait time dataset identifying the estimated wait time to a front-end device, thereby displaying the estimated wait time via the front-end device. 
     A third further example concerns a non-transitory computer-readable storage medium having embodied thereon a program executable by a processor to perform a method for queue wait time estimation. The executable method includes receiving mobile device location data associated with a plurality of guest mobile devices corresponding to a plurality of venue guests within a venue. The executable method also includes receiving event schedule data corresponding to schedules associated with a plurality of points of interest located within the venue. The executable method also includes generating an estimated wait time based at least on the received mobile device location data and the received event schedule data, the estimated wait time corresponding to a first point of interest of the plurality of points of interest. The executable method also includes transmitting a wait time dataset identifying the estimated wait time to a front-end device, thereby displaying the estimated wait time via the front-end device. 
     In a fourth further example, there is provided a queuing system for controlling access by a plurality of users to one or more attractions (that is, one attraction or a plurality of attractions). The plurality of users have a plurality of access keys and each access key is associated with at least one user from the plurality of users. The queuing system comprises: an electronic queue management part, configured to manage at least one virtual queue in respect of the one or more attractions, the electronic queue management part being further configured to receive electronic requests for attraction access, each request relating to a respective access key and being for the at least one user associated with the access key to access an attraction from the one or more attractions, receipt of each request causing the respective at least one user to be added to the at least one virtual queue and wherein the electronic queue management part is further configured to determine a time at which the respective at least one user in respect of each request reaches a front of the at least one virtual queue and can access an attraction from the one or more attractions on presentation of the respective access key; and an access control part, in communication with the electronic queue management part and arranged to control access to the attraction such that only a user presenting an access key at the determined time for accessing the (or each) attraction is allowed to access the (respective) attraction. In particular, no other normal access to the (respective) attraction may be permitted (although access for other types of users, such as disabled users may additionally be provided). Thus, each of the at least one virtual queue may be associated with a respective attraction. Then, the at least one user to which the request relates may be allocated to a virtual queue associated with the attraction to which the request relates (there may be one or multiple virtual queues for each attraction). 
     This provides a complete (100%) virtual queuing system, such that no user (referred to as a guest) queues in a physical line that operates in parallel (as opposed to series) with the one or more virtual queues. This provides a large number of improved opportunities for management of the virtual queue or queues. Although as mentioned above, there may be exceptional cases (such as a disabled user) that may be able to bypass the complete virtual queue, it may be possible to accommodate even such cases in the virtual queue. For example, disabled users may be managed through the system to avoid discrimination. This may further ensure that they avoid having to wait in line for long periods. 
     The electronic queue management part is optionally further configured to select one or more users from those allocated to a first virtual queue of the one or more virtual queues. The selected one or more users may each have a respective current position or wait time in the first virtual queue. Then, the electronic queue management part may be further configured to reallocate the selected one or more users to a reallocated position or wait time within the first virtual queue or within a second virtual queue from the one or more virtual queues. 
     In some examples, the reallocated position or wait time is either: (a) within the first virtual queue and more advanced than the current position or wait time (that is a position closer to the front and/or a shorter wait time); or (b) within a second virtual queue from the one or more virtual queues and the same or more advanced than the current position or wait time (that is a position the same distance or closer to the front and/or the same or a shorter wait time). This may allow users to be reallocated efficiently and fairly in an electronic queuing system. Optionally, the reallocated position or wait time may be less advanced (that is a position further from the front and/or a longer wait time compared with the current position or wait time) within either the first or second virtual queues. By selecting users (particularly only some of the users, as indicated below), the electronic system may be able to redistribute users to cope with unexpected events (such as a reduction in throughput or closure of an attraction) or to improve efficiency in respect of other attractions (for example, where their virtual queues do not provide sufficient users to maintain capacity). Typically, advancing the user within the queue or transferring the user to another queue either in the same or a more advanced position may be to their benefit, as it may result in shorter wait time overall until an attraction can be accessed (for instance if the attraction associated with the first virtual queue closes or suffers some throughput rate reduction). In some cases, pushing a user back in a virtual queue may be to their benefit. For example, the user may realise that they cannot make the time slot window they have been allocated and they may therefore obtain a time later than their current one. A small time slot window may help the system accuracy and may allow a user to push back and/or let the system know that they will be late. 
     The electronic queue management part is optionally further configured to keep a respective current position or wait time the same for each of the users allocated to the first virtual queue that are not the selected one or more users, when the selected one or more users are reallocated to the reallocated position or wait time. Additionally or alternatively, the electronic queue management part is further configured to keep a respective current position or wait time the same for each of the users allocated to the second virtual queue that are not the selected one or more users, when the selected one or more users are reallocated to the reallocated position or wait time (particularly in the second virtual queue). In other words, only the selected user or users may be reallocated and the positions or wait times of other users may remain unaffected. 
     In some examples, the electronic queue management part is configured to select the one or more users by receiving a request from the one or more users. Then, the electronic queue management part may be further configured to reallocate the selected one or more users in response to receipt of the request. Additionally or alternatively, the electronic queue management part may be configured to offer reallocation to at least one user allocated to the first virtual queue. Then, the selected one or more users may comprise one, some or all of the at least one user offered reallocation. In that case, the electronic queue management part may be further configured to receive a request from one or more users in response to the one or more users being offered reallocation. Then, the selected one or more users may comprise one, some or all of the one or more users from whom a request is received. Thus, the electronic queue management part may be further configured to reallocate the selected one or more users in response to receipt of the request. 
     In some examples, the selected one or more users comprise a user who has (or users who have) previously been reallocated to the first virtual queue from another virtual queue. Such users may, for example, be offered the opportunity to move forward (advance) and/or be moved forward (advanced) in the first virtual queue, when they have previously been reallocated to the first virtual queue from another virtual queue, for example a virtual queue for which the associated attraction suffered a problem, such as a reduced throughput or closure. 
     Optionally, the electronic queue management part is configured to manage at least one virtual queue in respect each of a plurality of attractions. Thus, each attraction has one virtual queue or a plurality of virtual queues associated with it. For example, an attraction can have a primary virtual queue that might be considered a normal (stand-by) virtual queue and a secondary virtual queue that might be deemed a priority virtual queue. One advantage of this approach is that the merge point of the two queues is itself virtual. Hence, a first guest A who is in the primary virtual queue presents themselves or their group at the front at the same time as a second guest B who is in the secondary virtual queue. Neither will have any idea how long the other has waited and only one access point to the attraction is needed. This will be discussed further below. In some examples, the electronic queue management part is configured to manage a first virtual queue in respect of a first attraction from the one or more attractions and to manage a second virtual queue in respect of a second, different attraction from the one or more attractions. Alternatively, the second virtual queue may be associated with the first attraction. 
     Optionally, each of the plurality of access keys comprises one or more of: a portable communications device (for example a mobile telephone, smartphone, watch device, tablet device or similar wireless communications device); a RFID device; a paper ticket; and a biometric feature. The use of an electronic access key may have advantages. For example, the electronic queue management part may be configured to receive the electronic requests through a wireless interface from an access key. In addition or alternatively, the electronic queue management part may be configured to receive the electronic requests from a system or device that is separate to the access key (for example, a booking kiosk), but which may be able to interface with the access key to allow identification of the at least one user associated with the access key. 
     Access to the attraction is allowed at a time set by the queuing system. This time may be a time range. For example, the determined time may comprise one or both of: an earliest time at which the at least one user can access the attraction; and a latest time at which the at least one user can access the attraction. 
     Optionally, the access control part comprises an access barrier for each of the one or more attractions. The access barrier may be configured to allow access by one or more users to the attraction on presentation of an access key associated with the one or more users at the determined time. For example, the access barrier may comprise a sensor configured to detect the access key (for example, by means of a wireless or RFID link, by means of a barcode, QR code or other coding on paper or electronic format or by biometric recognition). In some examples, the access barrier defines a physical buffer queue (for instance, the entry point of the physical buffer queue, which then extends to the attraction). The physical buffer queue may allow access to the attraction for all users that have passed through the access barrier. Multiple physical buffer queues per attraction may be provided. It should be noted that the physical buffer queue is in series (not parallel) with the at least one virtual queue managed by the electronic queue management part. Entry to a physical buffer queue is allowed only after reaching a front of the at least one virtual queue. 
     A change in the rate of throughput of an attraction (the throughput rate change), for example, closure (which may be unexpected) or throughput delay of an attraction may cause the at least one virtual queue and/or any physical buffer queue to become long and may result in a poor experience for users. Optionally, the electronic queue management part is further configured to detect a closure (typically unexpected) or throughput delay of an attraction (for example, by the provision of external information or by a sensor) and to allocate a user either in the at least one virtual queue or in the physical buffer queue (which may also be deemed part of a virtual queue) for the attraction to another attraction. As discussed above, this may be done by request of the user (by means of the respective access key, for instance) or automatically without request, for instance based on other criteria such as current time, time waited or a probability of reopening or increased throughput of the ride. Additionally or alternatively, the replacement attraction may be specified by the system or selected by the user from a plurality of attractions offered by the system. Optionally, the electronic queue management part is further configured to allocate the user in the at least one virtual queue or physical buffer queue for the attraction to another attraction with a priority setting. The advantage of a priority setting is discussed below. 
     Registration of the access key may allow the electronic queue management part to associate it with one or more users. In some examples, the queuing system may further comprise an access key registration part, configured to record an association between each access key and the respective at least one users associated with the access key. The access key registration part may be in communication with the electronic queue management part for communication of information about an access key in respect of which a request has been received. 
     Different types of virtual queue may be managed by the queuing system. For example, the electronic queue management part is optionally configured to manage each of the at least one virtual queue according to a predetermined wait time (variable throughput) or a predetermined throughput (variable wait time). The predetermined wait time or a predetermined throughput may be fixed or variable. In some examples, the electronic queue management part is configured to manage a virtual queue from the at least one virtual queue in the form of a queue sequence. However, alternatives to a queue sequence are possible. For instance, the virtual queue may be a statistical spread of users based on their request time and the attraction throughput, such as the system described in U.S. Pat. No. 8,606,605. 
     The electronic queue management part may be configured to reallocate the user within the at least one virtual queue to another attraction in response to receipt of a request to switch. For example, the electronic queue management part may be configured to reallocate the user within the at least one virtual queue to another attraction such that the reallocated position or wait time of the user remains the same. Thus, reallocation may cause no additional wait time for the user or users until they are able to access an attraction. 
     Optionally, the electronic queue management part is configured to manage the at least one virtual queue by predicting removal of or removing a number of users from a front of the queue according to a set rate (for example, a number of users per unit of time, such as a minute). This may be a predicted removal in the sense that an estimated wait time or attraction access time for one or more users may be based on the rate of predicted removal, although the actual rate of removal may depend on the rate at which users access the attraction or enter a physical buffer queue preceding the attraction access. The electronic queue management part is further configured to identify a throughput parameter of the attraction associated with the at least one virtual queue and to adjust each virtual queue, especially the first virtual queue, in accordance with the determined throughput parameter. The identified throughput parameter of the attraction associated with the virtual queue may comprise one of more of: a throughput rate of the attraction associated with the virtual queue; a change in throughput rate of the attraction associated with the virtual queue; a rate of change in the throughput rate of the attraction associated with the virtual queue. In particular, the electronic queue management part may be configured to manage a virtual queue (such as the first virtual queue) by predicting removal of or removing a number of users from the front of the virtual queue according to a set rate and to adjust the set rate based on the determined throughput parameter of the attraction associated with the virtual queue. The electronic queue management part may be configured to determine the time for the at least one user to access the attraction in response to the removal of the at least one user from the at least one virtual queue, for example if the users are removed from the front of the queue according to a set rate. 
     The electronic queue management part is beneficially configured to identify a decrease in the throughput rate of the attraction associated with a virtual queue, such as the first virtual queue. It may then be configured to inform the at least one user in the virtual queue in response to the identification. Informing the at least one user in the virtual queue if the throughput rate change is a decrease in the throughput rate may comprise offering to reallocate the at least one user to the second attraction. Such an offer may be an invitation for reallocation, as discussed above. 
     The rate of removal or predicted rate of removal from the front of the at least one virtual queue may be set according to different criteria. For example, the rate may be set on the basis of a number of users associated with a single access key in the virtual queue. This may allow multiple users associated with a single access key to access the attraction at the same time. The increase or decrease in predicted or actual removal rate may be offset by a corresponding decrease or increase in removal rate at a later time. Additionally or alternatively, the rate may be set on the basis of proportion (which may be 100% or less) of an attraction throughput or capacity. Optionally, the proportion is less than 100% or no more than 95%, 90%, 80% or 75%. Reducing the proportion to less than 100% may mitigate any problems due to the actual throughput of the attraction varying. The proportion is optionally set on the basis of a reliability performance for the attraction. The reliability performance may be based on one or more of: a variability of throughput for the attraction; a rate of unexpected closure for the attraction; a rate of unexpected closure for one or a more other attractions. 
     In another option (which may be combined with others), the rate (predicted or actual) is set on the basis of a length of the physical buffer queue. In addition or alternatively, the rate may be set on the basis of a rate of change for the physical buffer queue length. Optionally, the length of the physical buffer queue is used to determine whether one or more users are moved around in the at least one virtual queue, for example offered immediate access to the attraction or physical buffer queue if the physical buffer queue is too short or their reservation may be delayed in time if the physical buffer queue is too long. 
     In some examples, the queuing system further comprises a sensor, configured to measure or estimate throughput for the attraction over time, the rate being set based on the measured or estimated throughput. The throughput can be defined (and therefore measured or estimated) in a variety of ways, for example, in terms of: a number of users accessing the attraction per time interval; and/or the time taken by a user to advance a set length in a virtual queue and/or a physical buffer queue. 
     Optionally, the electronic queue management part is further configured to indicate to the user (optionally, via the access key) an estimated time to reach (or a time at which the user will reach) the front of the at least one virtual queue (such as the first virtual queue). The electronic queue management may be configured to indicate the estimated time to the at least one user via the access key associated with the at least one user. 
     The estimated time may be based on the set rate of predicted or actual removal. Beneficially, the electronic queue management part is further configured to update the estimated time at each of a plurality of times (for example, at regular intervals and/or based on another event, such as removal of users from the virtual queue) and to indicate the updated estimated time to the user. 
     This indication may be useful to the user generally, but it may also allow further interaction between the user and the queuing system. For example, the electronic queue management part may be further configured to receive a reject instruction from the user (such as from the access key) in response to the indication of the updated estimated time (especially if the estimated time for at least one user associated with an access key is updated to an earlier time from a later time and/or if the estimated wait time for the at least one user is updated to a shorter time from a longer previous time). Then, the electronic queue management part may be further configured to cause the estimated time to change back to the later time in response to the reject instruction. The reject instruction may be sent by the at least one user via the associated access key. A user or users selected for reallocation may comprise one, some or all of the user or users from which a reject instruction is not received. Alternatively, one or more users may provide an approve instruction (via their access key) and the electronic queue management part may be configured to receive this. Then, a user or users selected for reallocation may comprise one, some or all of the user or users from which an approve instruction is received. 
     In some cases, the reliability of the attraction may be greater than expected. The actual throughput for the attraction may be greater than the set rate of predicted or actual removal from the front of a virtual queue (or the sum of the rates for multiple virtual queues) associated with the attraction. In this case, a request may be made to one or more selected users as to whether they wish to bring their time forward (they can decline if, for example, they are already busy, such as having lunch or another ride). Alternatively, they can be pushed back, but given the opportunity to transfer to a different attraction rather than having to wait longer. 
     As noted above, closure or delays on the attraction may cause problems. Optionally, the electronic queue management part is further configured to detect a closure (planned or unexpected) or throughput delay of an attraction and to adjust the at least one virtual queue in respect of the attraction accordingly. The electronic queue management part may then be further configured to inform a user in the at least one virtual queue in respect of the attraction of the closure or throughput delay. 
     The electronic queue management part may be configured to invite the user to switch to another attraction in response to the indicated estimated time or the information or closure or delay. The electronic queue management part may be further configured to receive a request from the user to switch to another attraction in response to the indicated estimated time and/or information (and/or invitation). Then, electronic queue management part may be further configured to reallocate the user within the at least one virtual queue to another attraction in response to receipt of the request to switch. For example, the electronic queue management part may be configured to reallocate the user within the at least one virtual queue to another attraction such that the reallocated position or wait time of the user remains the same. Thus, reallocation may cause no additional wait time for the user or users until they are able to access an attraction. 
     The virtual queue may be managed in various ways. Priority management is a desirable part of the queuing system. In examples, the electronic queue management part is configured to determine that at least one user has a priority setting, thereby causing the position of the user in the at least one virtual queue to move forward at a faster rate than other users in the at least one virtual queue. Additionally or alternatively, the electronic queue management part is further configured to receive a freeze request in respect of at least one user in the at least one virtual queue causing the at least one user&#39;s position in the at least one virtual queue to be fixed, with all other users&#39; positions in the at least one virtual queue changing around the at least one user&#39;s fixed position. Then, the electronic queue management part may be further configured to receive an unfreeze request in respect of at least one user having a fixed position in the at least one virtual queue, thereby causing the at least one user&#39;s position in the at least one virtual queue to be variable. 
     In some examples, the at least one virtual queue comprises a first virtual queue having a first rate of predicted removal or removal from the front of the first virtual queue to access an attraction and a second virtual queue having a second rate of predicted removal or removal from the front of the second virtual queue to access the attraction. Optionally, the first and second virtual queues are managed in parallel by the electronic queue management part. This may allow users with a priority setting to be placed in a specific one of the two virtual queues, for example the second virtual queue. Beneficially, the electronic queue management part is further configured to control the addition of users to the first and second virtual queues and/or the first and second rates of predicted removal or removal, such that an average wait time for a user in the second virtual queue is less than an average wait time for a user in the first virtual queue. Thus, the second virtual queue may be used for users with a priority setting. 
     In a fifth further example, there is provided a method of managing a queuing system for controlling access by a plurality of users to one or more attractions. The plurality of users have a plurality of access keys, each access key being associated with at least one user from the plurality of users. The method comprises: receiving electronic requests for attraction access, each request relating to a respective access key and being for the at least one user associated with the access key to access an attraction from the one or more attractions; for each request received, adding the respective at least one user a virtual queue in respect of the attraction; managing the one or more virtual queues in respect of the one or more attractions (each of the at least one virtual queue being associated with a respective attraction of the one or more attractions, such that for each request received, the step of adding may comprise adding the respective at least one user to a virtual queue associated with the respective attraction); determining a time at which the respective at least one user in respect of each request reaches a front of the respective virtual queue and can access an attraction from the one or more attractions on presentation of the respective access key; and controlling access to the attraction such that only a user presenting an access key at the determined time for accessing the attraction is allowed to access the attraction, no other access to the attraction being permitted. 
     Optionally, the method further comprises selecting one or more users from those allocated to a first virtual queue of the one or more virtual queues, the selected one or more users each having a respective current position or wait time in the first virtual queue. Then, the method more optionally further comprises reallocating the selected one or more users to a reallocated position or wait time within the first virtual queue or within a second virtual queue from the one or more virtual queues. In some examples, the reallocated position or wait time is either: (a) within the first virtual queue and more advanced than the current position or wait time; or (b) within a second virtual queue from the one or more virtual queues and the same or more advanced than the current position or wait time. 
     This method example may be combined with features corresponding to those described herein with reference to the queuing system. A computer program, configured to perform any method as disclosed herein when operated by a processor or (digital) logic configured to perform any method as disclosed herein are also provided. The combination of any specific features from any examples is also provided, even if that combination is not explicitly disclosed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A number of specific non-limiting examples will now be described with reference to the following drawings. 
         FIG.  1    is a block diagram of a throughput and/or wait time estimation ecosystem  100  according to one or more illustrative aspects described herein. 
         FIGS.  2 A to  2 C  illustrates example graphs of instantaneous throughput and average throughput according to one or more illustrative aspects described herein. 
         FIG.  3    is a flow diagram illustrating exemplary operations for calculating an estimated wait time according to one or more illustrative aspects described herein. 
         FIG.  4 A  illustrates an example of a virtual queuing system showing schematic allocation of guests according to one or more illustrative aspects described herein. 
         FIG.  4 B  shows a variation in the length of an exemplary buffer queue over time according to one or more illustrative aspects described herein. 
         FIG.  4 C  depicts a schematic reallocation of guests in a buffer queue according to one or more illustrative aspects described herein. 
         FIG.  4 D  shows a schematic allocation of guests in a system with multiple virtual queues according to one or more illustrative aspects described herein. 
         FIG.  5    schematically illustrates interactions between user devices and a system operated in accordance with one or more illustrative aspects described herein. 
         FIG.  6    illustrates an exemplary computing system that may be used to implement one or more illustrative embodiments described herein. 
         FIGS.  7 A- 8    illustrate example graphical user interfaces that may be displayed according to one or more illustrative aspects described herein. 
     
    
    
     DETAILED DESCRIPTION 
     A throughput estimator is configured to forecast the throughput of a resource within a venue. The resource may be an attraction or point of interest within the venue, which may be a centrally managed collection of points of interest, such as a theme park. 
       FIG.  1    is a block diagram of a throughput and/or wait time estimation ecosystem  100 . The estimation ecosystem  100  may be used within a venue with multiple points of interest. The venue may be an entertainment venue or an event venue, which may include a theme park, a cruise ship, a school, a university, an arena, a concert venue, a ski resort, a relaxation resort, an ice rink, a shopping mall, a spa, a skate park, or a stadium. The points of interest of the venue may identify locations associated with attractions such as restaurants, cafeterias, concession stands, stores, libraries, theme park rides, theatre shows, movies circus shows, animal shows, or costumed characters. 
     Points of interest may also include locations associated with restrooms, water fountains, entrances, exits, or crossroads. An area such as an attraction or a restroom may be associated with multiple points of interest. For example, a given area may correspond to a number of entrances and exits or to multiple points of sale such as cashiers or card readers. 
     The estimation ecosystem  100  illustrated in  FIG.  1    centers around one or more application server(s)  125 . These application server(s)  125  obtain information  140  from one or more data source(s)  105 . The application server(s)  125  transmit data identifying current or future estimated throughputs and/or wait times associated with particular points of interest in the venue (e.g., attractions, restrooms, crossroads) via the communication network  130 . This data is transmitted by the application server(s)  125  to one or more front-end device(s)  135 . The application server(s)  125  and data source(s)  105  may be located within or outside the entertainment venue. The front-end devices  135  receiving the messages are generally located within the entertainment venue, but in some cases may be located outside of the same. For example, a mobile device may be associated with a guest who is about to enter the entertainment venue. Similarly, a device may be associated with a staff member who is working remotely or on the outside perimeter of the venue. 
     The estimated throughput and/or wait time data provided by the system of  FIG.  1    may estimate how long a guest will currently or at some point in the future have to wait to enter a ride, restaurant, restroom, or other “attraction” or point of interest at a venue. Wait times and/or throughputs may be computed based on the acquired information  140  using a calculation algorithm that allows calculation of estimates based on various types of information. For example, a Bayesian algorithm may be used to combine direct measurements around the point of interest, historical measurements around the point of interest, or measurements taken from other support systems not directly connected to the point of interest. Using the collected data  140 , it becomes possible to take a “snapshot in time” of the data sources and use them as inputs to predict current and future throughputs and/or wait times for any point of interest. The data sources  105  that make up the aforementioned supporting systems or that otherwise provided information  140  used in calculations may include mobile devices  110  (including wearable devices), point-of-entry (POE) or point-of-exit (POE) terminals/beacons  115 A, point-of-service (POS) terminals  115 B, or database(s)  120 . Point of service terminals  115 B may include cash registers, credit card readers, electronic payment receivers, or some combination thereof. 
     POE terminals/beacons  115 A and POS terminals  115 B can provide valuable information about traffic flow, and location data corresponding to mobile devices  110  that are interacting with the POE terminals/beacons  115 A and/or POS terminals  115 B even when the mobile devices  110  would not otherwise have signal reception. Database  120  may store historical data so that trends may be determined and used as part of the analysis (e.g., tracking how much traffic typically changes on weekends versus weekdays or at particular times of day). The mobile devices  110 , either alone or in combination with these other data source(s)  105 , may provide information  140  in the form of global positioning system (GPS) data or beacon proximity data. 
     The information  140  may also include social media data related to Facebook, Twitter, Instagram, Pinterest, Tumblr, or other social media accounts. Such social media data may include profile information, friend information, photos, message information, or some combination thereof. The information  140  may also include login information, guest settings, guest disability information, guest reservation status information, guest demographic information, entitlement information, customer relationship management (CRM) software information, weather information, queue length information, or some combination thereof. 
     The data sources  105  may also include information  140  from an administrator console  145  (e.g., which may in some cases be coupled to the database  120 , or to a mobile device  110 , or to a point of service terminal  1158 , or to a point of entry/exit terminal  115 A). The information  140  from the administrator console  145  may be generated via an administrator user interface allowing an administrator to manually enter information  140  to be collected by the application server(s)  125 . For example, an administrator could manually provide information identifying that a particular attraction will be closed for routine maintenance starting during a predetermined time range. Such an administrator console  145  may be a computer system  500  as illustrated in  FIG.  6   , or at least may include at least a subset of the components illustrated within the computer system  500  of  FIG.  6   . 
     A mobile device  110  of a guest of the entertainment venue may be both a data source  105  that provides information  140  to the application server(s)  125  and a front-end device  135  that receives estimated wait time data transmitted by the application server(s)  125  over the communication network  130 . Such a mobile device  110  may be a computer system  500  as illustrated in  FIG.  6   , or may include at least a subset of the components illustrated within the computer system  500  of  FIG.  6   . 
     The mobile device  110  may be a wearable device (also known as a “wearable”), meaning any type of mobile electronic device that can be worn on the body or attached to or embedded in clothes and accessories of an individual. Mobile devices  110  can execute an application (e.g., which may be embedded within an operating system, produced by a third party, or some combination thereof) that shares customer engagement information  140  with a venue&#39;s application server(s)  125 , receives estimated wait time data, or some combination thereof. The customer engagement data information  140  collected by the application at each mobile device  110  and transmitted to the application server(s)  125  may include a current location, a prior location, a customer wait time in a particular area, a travel time from one area to another, a path taken from one area to another, or some combination thereof. 
     Processors and sensors associated with a mobile device  110  can gather, process, display, and transmit and receive information. In some cases, the mobile device  110  of a guest may in fact include multiple electronic devices, such as a wearable device wirelessly connected to a “smart” phone, wherein both the wearable device and the “smart” phone include sensors that help obtain information  140  that is then passed to the application server(s)  125 , and wherein both the wearable device and the “smart” phone can received estimated wait time data as front-end devices  135 . 
     The system  100  of  FIG.  1    may be used with and communicate with any number of external front-end devices  135  by way of communications network  130 . 
     Communication network  130  may be or include an “intranet,” e.g., a personal area network (PAN), a local area network (LAN), a wireless local area network (WLAN), a municipal area network (MAN), a wide area network (WAN), or some combination thereof. The communication network  130  may feature direct or multi-node communication paths/channels that may operate utilizing any number of standards or protocols including TCP/IP, 802.11, Bluetooth, GSM, GPRS, 4G, and LTE. In some cases, the communication network  130  may include Internet connectivity. Communication network  130  may include a variety of connected computing devices that provide one or more elements of a network-based service. The communications network  130  may include actual server hardware or virtual hardware simulated by software running on one or more actual machines thereby allowing for software controlled scaling in a cloud environment. 
     The front-end devices  135  may be mobile devices, such as cellular phones (e.g., “smart” phones), portable media players, or portable video game consoles used by venue guests. Such front-end devices  135  may receive data identifying current or future wait time estimates corresponding to different attractions or points of interests, for example allowing a venue guest to decide an optimal time to visit a particular attraction or point of interest, or to have an estimate of how long the wait time at a particular point of interest will be once the guest reaches that point of interest after walking there or being transported there. An estimated wait time may be used by front-end devices  135  to provide further predictions based also on walking time to various points of interest (e.g., “head to this ride and get in line right away, it&#39;s going to be much busier soon!”). 
     A Point-of-Entry/Exit POE device  115  A, a POS device  115 B, or an administrator console  145  may be a front-end device  135  in addition to being a data source  105 . Thus, these devices may receive data from the application server(s)  125  identifying estimated wait times. For example, a staff member at a cash register (i.e., a POS device  1158 ) may receive an alert from the application server(s)  125  identifying that wait times are expected to drastically increase in the near future (e.g., because a nearby movie show just ended), and recommending that guest throughput (e.g., by opening another cash register) or guest capacity (e.g., by adding additional seats) be increased to alleviate potential issues before they actually occur. Thus, venues can prevent capacity and throughput problems proactively rather than reactively. 
     Front-end devices  135  are also inclusive of kiosks, staff mobile devices, staff wearable devices, venue devices, captive portals, and digital signs. Each of these devices may also be a data source  105  that provides information  140  not only about itself, but also about other devices that it interacts with. For example, a device operated by a staff member may report information  140  about a guest&#39;s mobile device  110  after an interaction between the two devices. 
     Calendar of Events 
     Scheduled events may be input to the throughput estimator and the throughput estimator may take the scheduled events into consideration when predicting the throughput of the resource. Doing so may comprise assessing or estimating the impact of the events on the throughput of the resource and adjusting the estimated throughput accordingly. 
     One example of an event that may impact the throughput of a resource is scheduled cleaning of the resource. Regular cleaning of attractions has become increasingly important in view of concerns over infectious diseases that may be transmitted via contact with unclean surfaces. 
     On the other hand, the system can also be used to identify times when the attraction throughput does not match the scheduled demand for the attraction. There may be times when a ride is busier or less busy than usual. This can be caused by changes in weather, natural variation over the day (e.g. at lunchtime). As a result of these fluctuations, an attraction may be operating at greater or lower capacity than required for the number of guests in the queue (buffer queue or virtual queue). In response to such a determination, the system may be able to schedule events to assist with matching the attraction throughput with the demand. For example: If the ride is quiet, bring a scheduled cleaning forward; If the ride is busy, add an additional train; If a restaurant is busy, redistribute staff to that restaurant 
     If a ride breaks down, there may be no way to increase the throughput to match demand. In this case, throughput on other attractions may be increased e.g. by adding trains on those attractions and users that were previously queuing for the now broken attraction can be invited to join a queue for an alternative attraction. 
     An example may be that a queue for an operation attraction running at capacity has an event scheduled to add an additional train. The attraction will then be running at half capacity when the train is added, in the absence of any corrective action. Users from the queue for the broken attraction can be inserted into the virtual queue for the operational attraction to increase the demand at the time the new train is scheduled to be added to match the predicted throughput. 
     In another example, a train is scheduled to be added in 1 hour to match normal fluctuations in demand. A ride unexpectedly requires cleaning and so needs to be temporarily closed. The time at which the train is scheduled to be added may be brought forward to counteract the demand that was not catered for while the attraction was out of service. 
     In this way, the resources in the park may be utilised more effectively. Where attractions are operating at less than full capacity (i.e. with empty seats) energy is wasted in operating those rides, as compared to operating those rides with all the seats full every time. The proposed system therefore improves the efficiency of the park. 
     In some examples, the system may use historic data of ride throughputs to help adjust the expected throughput figures. This may involve training a model with historic data to predict future throughputs. 
     Calculating Waiting Times 
     When calculating a waiting time for a queue (whether for a physical queue or a virtual queue) the following simple formula may be used: Wait time for user joining=Number of users in the queue/Throughput of the queue. 
     The number of people in a queue may be referred to as the “length” of the queue. The time that a person joining the queue has to wait before accessing the attraction is referred to as the “wait time”. The total wait time may be comprised of a wait time in a virtual queue, followed by a wait time in a physical buffer queue. 
     In this simple version of the calculation (which may be employed in prior art methods), the throughput of the queue is assumed to be constant. However, one or more aspects described herein acknowledge that there may be occasions when throughput of a resource changes, for example:
         Regular cleaning (throughput=0 for a specified number of minutes);   Adding more trains (e.g. going from 2 to 4 trains, throughput=0 for 10 minutes to add the trains, then throughput will increase to a given number or the previous throughput will double);   For a restaurant, from there may be more staff during popular times (e.g. 12 pm-2 pm). The capacity of the restaurant may therefore be increased during these times where staff numbers are higher. More staff may be added so that the number of bookings can be increased, if increased demand is detected.       

     These events may be used to predict how throughput is likely to change over time. The queue wait time estimator may then use these forecasted changes in throughput to give a more accurate wait time. 
     Two important factors for determining a queue wait time are: the throughput, both now (operating throughput) and during the period that the person who just joined the queue is actually in the queue (estimated throughput); and number of people in the queue, which can be determined by: counting the number of people in a virtual queue or maintaining a running tally using queue management software; processing images of the physical queue to estimate the number of people in the queue; monitoring the rate at which users are joining the physical queue and leaving the physical queue to determine changes in the length of the physical queue, an maintaining a running estimate. 
     In one example, a ride may operate at 800 guests/hr with one train and 1200 guests/hr with 2 trains. The venue may put one train on at the start of the day. Then, at some point during the day, which will be planned based on expected attendance, the second train may be brought into operation. This may take a few minutes, during which the ride is not running. Thus the throughput goes from 800 guests/hr to zero guests/hr for a changeover period (e.g. 5 minutes) to 1200 guests/hr after that. The time at which the changeover happens can be scheduled. 
     In a further example, if a ride shuts, the park could be prompted to add more trains on another ride. So that users that were previously intending to go on the closed ride have an alternative to go to that has increased capacity. 
     In yet a further example, where users have been queuing for a ride that breaks down, a new virtual queue could be added for these new trains on the alternative attraction, so that the guests that were in the queue for the ride that shut can be offered an alternative that takes into account the time already spent queuing, so that they are not disadvantaged. 
     Maintenance/shift change events may be delayed or brought forward to ensure that guests are well catered for. In other words, the throughput of the resources may be managed to meet the demands of the venue guests. For example, a scheduled maintenance window may have been created so that an attraction is due to close at a particular time. The queue may be managed so that users are prevented from joining the queue at a certain point, so that the queue is empty at the time the attraction closes. However, if the throughput of the attraction is lower than predicted (e.g. because a ride was running more slowly), there may still be people in the queue at the time the attraction is due to close. These people would face a long wait, as they would need to wait the entire duration of the maintenance window, as well as the normal queue time when operation resumes. To address this, the system may push the maintenance window back, to ensure all those guests that joined the queue before the attraction temporarily closes get through before the attraction closes, and don&#39;t have to wait any longer. 
     Demand for an attraction may be expressed in terms of a rate at which users join the queue. Where the wait time is increasing due to increased demand, this may be quantified using the rate of change of the wait time (the differentiated wait time). To estimate this, the rate of growth of a queue may be measured (e.g. using cameras or beacons). In a venue having multiple resources, park management software may use the queue lengths and attraction demands to help balance the guests within the venue. For example, the throughput of a resource may be reduced in order to increase the queue length (or the advertised wait time may be exaggerated). This will induce guests to visit other areas of the park where queue times are shorter. Alternatively, throughput of another resource may be increased to decrease the wait time for that resource and therefore induce guests to move to that area of the venue. 
     One way in which the utilisation of a resource may be monitored is by monitoring the size of a buffer queue associated with the resource. If the queue becomes too short, the attraction may begin to operate with empty seats. If the queue becomes too long, guests spend time waiting in line that they could spend on other attractions. To monitor the size of the buffer queue, video of the physical queue may be used. 
     PID control may be used to regulate the length of the buffer queue at the desired value. 
     One other way is to use historic data to predict how queue parameters will behave in future. The queue lengths can be measured alongside other relevant factors that may be correlated with the queue length and the data can be used to train a model. Queue measurements are likely to be similar on similar days, for example. 
     The estimated throughput of the resource may be used for estimating queue wait times, which may then be displayed to users in the venue via front-end devices, such as display screens or mobile phones. Methods for estimating queue wait times are discussed in more detail in U.S. patent application Ser. No. 15/141,780, which is herein incorporated by reference. 
     An average throughput may be calculated for the resource. The average throughput may be used in the waiting time calculation: Wait time for user joining=Number of users/Average throughput 
     When referring to an “average” in this example, this refers to the average over a defined period. In the case of  FIGS.  2 A- 2 C , this is the running average, from t=0 up to the time in question, plotted at the x-coordinate. 
     In other examples, the average wait time may be calculated for the period the user is in the queue, for example. 
     A worked example of calculating an average throughput for a resource is provided below. 
     Consider a resource with a variable throughput. If the throughput changes from Ta to Tb (assuming neither is equal to 0), the average throughput can be calculated as a weighted average of the two throughputs.  FIG.  2 A  illustrates a graph of instantaneous throughput and average throughput (measured in people per second) against time (in seconds). In this example, an initial throughput Ta=6 people/sec. Subsequently, the throughput changes to Tb=10 people/sec. 
     During a 100 second period, the resource has a throughput of to for 40 seconds Ta and a throughput of Tb for 60 Seconds. Total time=100 seconds, throughput=840 people (6*40/100+10*60/100). 
     However if the resource stops, the average cannot be calculated whilst the queue is stationary as nobody leaves the queue. The wait time would be infinite if a throughput of zero were recorded. Therefore, this period may be removed from the timing before the average is calculated, then the time removed added back in. 
     If the resource no longer admits people from t=50 to t=60, then the time from t=50 to t=60 may be removed from the graph. This is illustrated in  FIG.  2 B . 
     This time will then be added back in to the wait time for any t&gt;50. The corrected graph is illustrated in  FIG.  2 C . As can be seen in  FIG.  2 C , the removed time period is added back in, so that time is continuous on the x-axis. Therefore, the graph contains a gap where the throughput is zero. 
       FIG.  3    is a flow diagram illustrating exemplary operations  200  for calculating an estimated wait time. In particular,  FIG.  3    outlines how the application server(s)  125  gather information  140  and use it to calculate an estimated wait time. It should be noted that the steps of  FIG.  3    are exemplary and need not occur consecutively as illustrated in  FIG.  3   . Various steps illustrated in  FIG.  3    and discussed below may occur consecutively, concurrently, or intermittently. For example, information from steps  210 - 250  may be received concurrently with respect to undertaking the calculation described with respect to step  260 . Further, various steps may be occasionally, routinely, or temporarily omitted from the analysis process. 
     Information  140  can be collected by the application server(s)  125  through multiple methods. For example, information  140  may be collected through connected devices (guest mobile devices report detection of a POE beacon/terminal/geofence/waypoint  115 A or vice versa). Information  140  may also be collected through sensors installed in the venue reporting a device location (connected iBeacons, Wi-Fi, RFID). Cameras installed in the venue identifying guests via facial recognition may also be information sources. 
     At step  210 , a “direct” wait time may be measured and provided to the application server(s)  125  either automatically via location data (e.g., GPS location data from mobile devices  110  and/or POE locations beacons  115 A). Measurement may also occur via visual tracking effectuated either manually by staff (e.g., entered via an administrator console  145  or POS terminal  115 B) or automatically via cameras with facial recognition. The “direct” wait time may be a measurement based on tracking guests from a start of a line until entry into the point of interest (or in some cases until exit from the point of interest). 
     This information may be analyzed via comparison of timestamps collected when mobile devices  110  corresponding to particular guests are tracked at certain locations corresponding to a line and to an entry or exit. Examples include a movable POE terminal/beacon  115 A at the beginning of the line, a POE terminal/beacon  115 A at the entry to the point of interest, and a POE terminal/beacon  115 A at the exit of the point of interest. The application server(s)  125  may receive the direct wait time data in the form of these timestamps. 
     At step  220 , location map data is received at the application server(s)  125 . Locations of venue guests may be tracked in real-time, periodically, or only at certain waypoints such as point-of-entry beacons  115 A or point-of-sale terminals  1158 . A location map can be generated from all of these disparate location points tracking all known guest locations for a given area. The area could be only an area relevant to one point of interest, such as a line area. The area can be expanded to include a predetermined radius around the point of interest or to include other neighboring points of interest, thus allowing the location map to detect and predict individual guest movements and larger guest group migration events, such as a large number of guests exiting a movie theatre or show at once when it finishes. The location map may be generated by inputting locations and corresponding times, dates, days of the week, months, years, self-reported wait times, and other information into a wait time calculation algorithm. The wait time calculation algorithm may be applied to ignore or minimize (negatively weight) points with missing data. 
     Information received and provided over communications network  130  may come from other information systems such as the global positioning system (GPS), cellular service providers, or third-party service providers such as social networks. The system  100  can measure location and proximity using hardware on a user device (e.g., GPS) or collect the data from fixed hardware and infrastructure such as Wi-Fi-based or cellular-tower-based positioning systems and Radio Frequency ID (RFID) readers. An exemplary location and proximity implementation may include a Bluetooth low-energy beacon with real-time proximity detection that can be correlated to latitude/longitude measurements for fixed beacon locations. 
     If a guest arrives at ride entry waypoint, then departs, then arrives and departs again during a configurable period (i.e. the length of the ride), only the first or last departure event might be tracked. This addresses the scenario where guests exit the ride at the same location that they board, so they&#39;ll be spotted twice: once before they ride and once after. Not all rides are configured this way, however, since with some rides, guests may disembark at an exit that is located in a different place than the entrance, and thus may be tracked separately. 
     At step  230 , the application server(s)  125  receive network traffic measurement data. The network traffic includes network traffic of guests within the venue as determined by network connected sensors. For example, guests connecting to (or being detected by) Wi-Fi hotspots, Bluetooth beacons, or near-field-communication (NFC) devices such as radio-frequency identification (RFID) devices may provide another method of tracking locations of guests. Furthermore, if it is detected that guests are using their mobile devices  110  to search for information about a particular point of interest, a probability may be entreated into the wait time calculation algorithm later that that guest may be headed toward that particular point of interest. 
     At step  240 , the application server(s)  125  receive entitlement redemption event data. This may include various promotions being offered by the venue, such as discounted tickets to the venue on certain days of the week/month/year. Entitlement redemption event data may also include promotions being offered by certain points of interest within the venue, such as discounts/offers at certain restaurants, free rides for certain theme park attractions. Entitlement redemption event data may also include promotions being used by guests, for example identifying that a certain promotion has turned out to be extremely popular or unpopular. Entitlement redemption event data may also include some combination of the above-recited categories of entitlement redemption event data. Promotions and entitlements can ultimately influence wait times by driving up probabilities that guests will be at the venue, or that guests will head to certain points of interest at the venue at certain times. 
     At step  250 , the application server(s)  125  receive show and event schedule data. This allows the wait time calculation algorithm to predict when large crowds might exit a particular point of interest, such as a scheduled end of a movie or show, and head to other nearby points of interest, such as bathrooms, restaurants, or rides. Similarly, this allows the server  125  to predict when large crowds might enter a particular point of interest, such as a discounted time period or a grand opening of a new attraction at the venue. 
     At step  260 , the application server(s)  125  calculate an estimated wait time using the wait time calculation algorithm. The wait time calculation algorithm may use probability calculations, particularly if it is a Bayesian algorithm, and may in particular factor in probabilities of various occurrences based on all of the real-time and historical data it receives (e.g., information  140  of  FIG.  1    and/or steps  210 - 250  of  FIG.  3   ). Based on this information, the wait time calculation algorithm may accurately predict current wait times and future wait times. The wait time calculation algorithm may be based on Bayesian algorithms, nearest-neighbor algorithms, alternating squares algorithms, or some combination thereof. In some embodiments, the wait time calculation algorithm may be replaced with or used in combination with artificial intelligence or machine learning techniques/systems, such as neural networks, and may self-train and self-correct by estimating future wait times, seeing how accurate its estimates turned out once that “future” time comes to pass, and adjusting its later-predicted wait time estimates accordingly. 
     This concept can be expanded in a number of different ways. For example, additional metadata may be added to the wait time calculation algorithm inputs such as time of day, day of week, season, show schedules, and the like for more accurate results. Guest travel time to get to a ride (e.g., the guest is 15 minutes away) may also be factored in such that the algorithm could be used for predicting what the wait time will be in 15 minutes. Instead of showing the current predicted wait-time, the results can be personalized to show the estimated wait time when the guest arrives (or allow the guest to see expected wait-times through the remainder of the day to better plan their trip). The same solution could be used not just to predict wait times at a point of interest, but generally for predicting heavy or light traffic anywhere within the venue. For instance, if show schedules are one of the inputs, the line length at the food court could vary significantly depending on whether there is a show which ends at 11:30, 12, or 12:30. 
     Other information could also be used to generate the estimated wait time, such as thermometer data, barometer data, hygrometer data, wind vane data, rain gauge data, light sensor data, weather forecast data, a national/local holiday calendar, a local school vacation calendar, a current tide level measurement (e.g., which may affect aquatic or beach-related venues), a tide forecast, power outage data, seismometer data, smoke detector data, air quality data, emergency detection data, emergency forecast data or some combination thereof. Emergency detection data may include sensor measurement data identifying forecasts earthquakes, tornadoes, fires, tsunamis, or other natural or man-made disasters. Emergency forecast data may include data suggesting that such emergencies are likely to happen. For example, if the venue is near a body of water, information identifying that an earthquake has occurred near the same body of water may suggest that a tsunami or aftershock earthquakes are both likely to affect the venue in the near future. 
     At step  270 , the application server(s)  125  transmit data that includes estimated wait time(s) to one or more front-end devices. This data can take many forms so as to be compatible with different applications and user interfaces. The report time may be reported to a mobile device  110  of a guest at the venue through an application installed on a device such as a mobile device  110 . In some instances, wait times can also be displayed on signs at the line entrance to the point of interest, or on signage provided in the line or waiting area. Signage could be manually updated by staff or updated automatically on digital displays that are front-end devices  135 . 
     Measuring the Queue 
     Determining a length of the queue may be performed using queue management software where the queue is a virtual queue. A queue management server may keep a record of the users added to the queue and those that have left the queue and the length may be calculated by the software from the live queue data maintained by the server. However, where the queue is a physical queue, determining the queue length may be more difficult. There are a variety of techniques provided into this application that may be used to measure the number of people in the queue. 
     A first method of measuring the length of a physical queue uses image or video monitoring of the queue and image processing techniques. 
     In a first example, an image of an area is obtained when the venue is empty, to provide a reference image with no people in it. Using this image, a first map may be generated to mask off areas of the image that are to be excluded from analysis (e.g. because they do not form part of the queue). 
     A second map may be generated from the image to provide a greyscale gradient map of the included areas, to provide a weighing value to each pixel. This second map may be used to account for perspective in the image, so that areas that are further away (where objects appear smaller in the image) are given a higher weighting. This technique may provide a simple way to account for perspective, rather than trying to remove the perspective using image processing techniques, which can distort the image. 
     Then, one or more further image of the venue are obtained when there are venue guests present. Image processing techniques may be used to identify differences between the images that are due to guests being resent in the venue. Image processing may be used to normalise lighting conditions and ignore noise so that only guests are detected. The number of pixels in the images that are attributed to venue guests may be used to provide and estimate of the number of guests visible in the image. 
     The process may be repeated regularly (e.g. ten, twenty, thirty or sixty times per second, or once every one, ten, twenty or sixty seconds, or once every one, ten, twenty or sixty minutes), so that an image of the area is periodically obtained and an updated estimate of the number of guests in the queue may be derived. 
     Each image may be processed individually to obtain an estimate. Alternatively, video processing may be used to track changing numbers of guests over time by taking data from previous image frames into account (e.g. by tracking movement of guests between image frames). 
     In another example, rather than analysing individual pixels, an algorithm may be used to draw a boundary around areas of the image containing people (if they are tightly packed this will give a large area, individuals will give a smaller isolated area). 
     In a specific example, the number of users may be estimated by: determining the area corresponding to the queue (minus any “holes” in it); applying (multiplying) the greyscale mask to calculate a value that give the perspective-adjusted area (closer to the camera the person would appear larger, so would take up a larger area, the greyscale would therefore need to be darker and each pixel would count for less to account for this; further away, each pixel counts for more); and multiplying the adjusted area by an approximate density of people (which may be estimated using head-counting techniques). 
     By monitoring a number of different areas of the queue with separate cameras, the totals from each camera can be combined to provide the total number of people in the queue. 
     In another example, the cameras may be used to identify the end of the queue. If one area in a queue is not empty, potentially the part of queue ahead need not be processed, as it can be assumed to be full. 
     The greyscale map may be generated automatically (e.g. by determining the height of a single person at a number of points in an image from a camera). The greyscale mask may be used as a way of accounting for perspective, as described above. 
     Alternatively, where the geometry of the scene is fixed (e.g. because the camera is stationary) an image transformation (such as a homography) may be used to account for perspective. 
     There are advantages to estimating the number of people using the visual area-based method. Identifying individual people in a crown to count them may be inaccurate. By identifying an area, no individuals are identified (merely the shape and area of the queue). Therefore, no personal information is generated. 
     Other methods of determining the length of the queue may involve counting people joining the queue and counting people leaving the queue. However, if there are errors in the numbers counted, maintaining an estimate of the number of people in the queue using the counted numbers may be inaccurate (because the total is effectively an integral of the change and therefore any errors may persist or increase). Therefore, the numbers counted need to be reliable. In contrast, the visual area-based method is able to provide an estimate in which errors do not grow over time. 
     By measuring the total number of people in the queue and measuring the number leaving the queue, the number of users joining the queue may be calculated (which is effectively a differentiation step, so any errors will tend to remain stable or reduce). This may provide an estimate of the demand for the resource. 
     A second method of determining a length of a physical queue is to monitor the number of users joining the queue and the number of users leaving the queue via the attraction (assuming that users do not exit the queue without going via the attraction). One way to do this is by using electronic scanners at the entry and/or exit of the queue. 
     In a case where there is a virtual queue and a physical queue (also called a buffer queue) operating in series, users may only be permitted to enter the physical queue once they have reached the front of the virtual queue. To validate this, users may each have an access key and may be required to scan the access key at an access barrier in order to gain access to the physical queue. 
     Requiring a user to actively scan an access key in order to gain access to the physical queue (e.g. using an radio-frequency identification, RFID, reader) provides an accurate way to determine the number of users that have joined the physical queue and the rate at which users are joining the physical queue. 
     To measure the rate at which users leave the physical queue, the access keys may be scanned again at the exit point of the queue. However, requiring users to actively scan out of the queue can create delays in loading the resource and therefore impact the efficiency of the resource. Therefore, it is preferred that users do not have to actively scan an access key to leave the queue. Instead, beacons may be placed at the exit of the queue and the access keys may be detected passively (by detecting access keys that are in the vicinity, rather than requiring the user to present the key to the reader). 
     This passive scan method (e.g. using Bluetooth) may not be 100% efficient at detecting every user that leaves the physical queue. Therefore, the queue manager may maintain a record of the order in which users joined the physical queue, from the order in which the users actively scanned in as they entered into the physical queue. Assuming that the users stay in approximately the same order in the queue, the system may infer that if two users have been detected at the queue exit, any users that joined between the joining times of those users are also likely to have left the queue. In this way, the problem of errors accumulating over time can be reduced. 
     To improve the rate of success of detecting users, an additional detector could be placed at the exit point of the resource (in addition to the exit point of the queue). This additional detects people coming off the ride and this data could be combined with the data from the detector at the queue exit to improve the throughput estimate (taking the ride duration into account). 
     Wait times may also be measured directly. The beacon-based scanning system described above may be used to provide a measurement of the wait time for the resource. The wireless beacons may be used to detect a wireless device at the entry point and exit point of the queue. It can then transmit this to a server. Other methods for directly measuring queue wait times are discussed in more detail in U.S. patent application Ser. No. 15/141,780. 
     Measuring Throughput 
     Throughput for the resource (also called the attraction) may be measured by counting people moving through the access point for the resource. Alternatively, the passive scan system described above may be used to provide a measurement of the throughput of the resource. A wireless beacon may be placed at either end of the physical queue. Then, as a user with a wireless device that can interface with the beacon passes it, the device records the time. The device also records the time when it passes the end of the queue. It can then transmit this to a server. An advantage of this approach is that the queue ends can be moved easily, with no need for power or networking, which is instead reliant on the user device. 
     The system may only need to measure a proportion of the guests rather than 100% to extract the necessary information (for instance, it may know how many have gone into the queue as they have been scanned previously). 
     Since not every user may be detected when leaving the queue, the system may use an order in which the users joined the queue (where users are required to active scan to enter the queue), to fill in the gaps in the data. 
     If the beacons for detecting exit from the ride detect no users in a given timeframe, the queue manager may assume that the ride is operating at a constant throughput rate (using the measurement from the last time the beacon detected a user). Once another user is detected, the throughput estimate may be updated. 
     The visual area-based method for estimating queue length may also be used to measure throughput. By measuring the total number of people in the queue and measuring the number joining the queue, the number of users leaving the queue may be calculated. This may provide an estimate of the throughput of the resource. 
     Virtual Queuing 
     The estimated throughput of the resource (and calendar of scheduled events) can be used to manage a virtual queue that feeds into a physical buffer queue for the attraction. Methods of managing such a virtual queue are described in more detail in U.S. patent application Ser. No. 15/315,712, which is herein incorporated by reference. 
     Virtual queues offer benefits to attraction operators and users (also referred to as guests in the context of an amusement park, for instance), since time spent waiting in a physical queue is considered wasted and could be spent on other activities. It may therefore be preferable for users to spend most of the overall queue time queuing virtually, so that they can visit other attractions, such as cafes and amusement stands, while still effectively waiting in the queue. 
     One reason for maintaining a physical queue in addition to the virtual queue is to ensure that there are always enough people ready to utilise the resource, so that resource capacity is not wasted. 
     To balance these needs, it may be preferable to keep physical queue short but not empty (for example, 10 minutes). Fluctuations in the throughput of the resource can lead to fluctuations in the length of the buffer queue. Therefore, the virtual queue feeding into the physical queue must be managed to maintain the length of the physical queue. In order to do so, measurements of the length of the physical queue and the throughput of the resource are useful. 
     There are different ways of operating a virtual queue. In one method, the guest may be sent a notification when they have reached the front of the queue and are permitted entry to the physical queue. In this method, the rate at which users join the physical queue can be easily controlled (because the rate at which guests are summoned to the physical can be controlled to manage the length of the physical queue). There is a small delay between summoning a user and them arriving at the queue, because they may take some time to travel to the queue point. However, for this method to work, a reliable communications network is required, so that summons may be received by the user, wherever they are in the venue. 
     In another method, the user may indicate their desire to join the virtual queue (e.g. by scanning their access key at an entry point) and be given a time at which they can return and enter the physical queue. If the time is fixed then no communications network is required, because the user is given their arrival time straight away. However, the physical queue may be more difficult to manage in this way because the rate at which users reach the front of the virtual queue (and so are permitted access to the physical queue) is set ahead of time. For example, if the length of the virtual queue is three hours, it will take three hours before an adjustment to the throughput of the virtual queue is reflected in the rate at which users join the physical queue, because the arrival times of the guests that have already joined the virtual queue cannot be changed. 
     In yet another method, the user may indicate their desire to join the virtual queue and be given a time at which they can return and enter the physical queue. However, this time may be a provisional time that is subject to adjustment. A long-range broadcast system (e.g. Sub-GHz radio) may be implemented in the venue so that the access keys can receive updates to their entry time. If the length of the physical queue is outside of the preferred range, the virtual queue wait time may be adjusted to decrease/increase the length of the physical queue. For example, if the queue is too long, everyone&#39;s arrival time may be pushed back by 5 minutes, to allow the queue length to reduce. In this way, the entire virtual queue may be updated, by broadcasting a message that the queue is now n minutes shorter/longer. 
     If the broadcast system is not 100% reliable, some guests may not receive the broadcast message. However, as long as the message reaches a majority of the access keys then this may nevertheless provide an effective method to adjust the throughput of the virtual queue and impact the rate at which users join the physical queue. This method therefore provides enhanced control over the physical queue, without requiring a communications network that is 100% effective. 
     An example of a virtual queuing system is explained with reference to  FIG.  4 A . In this Figure, a schematic representing an allocation of guests (interchangeably referred to as users) in a virtual queue according to an embodiment is shown. The system includes an attraction entry point  101 , a buffer queue  102 , a barrier for entry to the buffer queue  103 , and at least one virtual queue  104 . 
     When a guest makes a reservation (the process for doing which will be explained below), they will be entered into a virtual queue  104 . The throughput of the virtual queue (the number of guests per unit in time) will be determined by parameters in the system and will be arranged to have an average throughput  150 . This is also set as a parameter of the queue and is, for example, a percentage of the maximum throughput of the ride. Guests are shown their reservation time either on their portable communication device or at a kiosk. 
     The guests in the queue may be moved around if necessary by the system as they can be waiting anywhere (for example in an amusement park, other enclosure of attractions, village, town, city or wider area), they may be allocated a new reservation time or prompted to select one, based on various events. 
     At their allotted time, the guest presents themselves with an access key or device, which may be a mobile telephone, smartphone, RFID device (such as a card, wristband or other wearable item), a card or wearable item (such as a wristband) with a visual code (such as a barcode), paper ticket, body part (for biometric identification) or other device showing that they can access the attraction, at the barrier for entry to the buffer queue. The barrier  103  may be automatic or manual. They then wait in a short buffer queue  102  to get onto the attraction through the attraction entry point  101 . 
     In cases where the buffer queue  102  is not necessary, the barrier  103  and the attraction entry point  101  will be one and the same. 
     The buffer queue  102  has an optimum length  106 . Changes in the length of the buffer queue from this optimum are signalled back to the system, either through automatic sensing apparatus or via an attendant  107 . 
     The queue or queues in which guests are placed, prior to being granted access to the buffer queue (through the entry barrier  103 ), is/are managed by the queue manager, which is an electronic (computerised) system. These queues are entirely virtual queues. Advantageously, this allows guests to queue for an attraction without having to physically stand in a line. There may be different types of virtual queue, as will be discussed below. Although the queue manager may also manage the physical buffer queue  102 , access to this is only available through the virtual queues. 
     This system will support a park, for example, where there are a number of rides or other attractions. One or more of the available attractions may be managed by the queuing system. The system supports different queue types, for instance: where the throughput of the ride is fixed, so the length of queue is a function of the number of guests waiting in that queue; and where the wait time in the queue is fixed, so the throughput of the queue varies and is a function of the number of guests in the queue (any variation in the queue throughput can taken up with a variation in the physical buffer queue  102 , for example). 
     Other types of queue, such as where the throughput and/or wait time are variable are also possible. 
     A purpose of the buffer queue  102  is to allow optimum loading on attractions where there is a fixed number of spaces available (such as an amusement park ride). For attractions where there is some flexibility in the throughput (for example, a museum or walk-through attraction) this buffer queue  102  may not be necessary. The optimum length of this buffer queue  102  can be set in the system. This may be different for each ride. 
     With reference to  FIG.  4 B , it is shown how the length of the physical buffer queue may vary over time. The rate of throughput of the virtual queue can be set as a proportion of the expected maximum throughput of the ride. By setting the rate at less than the maximum throughput, the steady state will be for the buffer queue to decrease in length  301 . When the queue gets too short, this state is signalled back to the system controller which will cause a block of guests to be granted faster access to the front of the queue through a variety of means  302 . This will take a few minutes to be seen in action, and will result in the queue length increasing  303 . If the attraction closes for a short period, this will result in the buffer queue increasing in length as guests are fed onto it but are not leaving onto the attraction  304 , when the attraction reopens the queue will decrease once again. 
     To cope with the inherent unknowns of an attraction, the throughput of guests at the front of the queue can be set as a percentage of the throughput that the ride can cope with. A more unreliable ride may have a lower allocation proportion. In a steady state, the entry to the buffer queue being below the throughput of the attraction, the buffer queue will decrease in size with time. 
     A system to monitor this buffer queue and send back the state will enable the system to bring forward a block of guests when the ride buffer queue gets too short. This will refill the buffer queue, which will then gradually shrink through time. The guest may be prompted to decide whether they wish to advance towards the front of the queue (this may correspond to the guest being allocated an earlier reservation time). Those guests who do not want to move their place need do nothing. Optionally this method of calling forward guests can prioritise certain groups of guests, such as those nearer the front first, those who have had their records flagged with a marker as a result of ride closures or other unexpected events. 
     Similarly if the queue becomes too long, the system may push guests back by increasing their reservation time. In this way, the rate at which users join the buffer queue and the overall length of the buffer queue may be controlled. Additionally or alternatively, the virtual queue can be set in the form of a fixed throughput queue. 
     The guest may be informed on their communication device that their reservation time is delayed. Certain types of guest (for example with pre-bought timed tickets) would potentially not be pushed back. 
     If the ride closes, the buffer queue will increase in length. When the ride reopens, the queue will then start to decrease again. 
     Thus, the rate at which users are removed from the virtual queue is the sum of: the physical rate at which they present themselves at the attraction (or its physical buffer queue) and go on to it; and the rate of those that have missed their allocated time slot and are therefore automatically removed from the queue. The predicted time given to each guest is set depending on the set rate of the virtual queue (which may be a percentage of maximum throughput of the attraction). If we expect 600 people per hour to be processed at the attraction, every minute will contain 10 people. The system can spot gaps in this (for instance, users cancelling) and fill these gaps, as explained above. This differs from existing systems, in that the number booking is known when a request is received (since the system is a complete virtual queuing approach), so a ride time is allocated based on the predicted throughput. If this throughput is changed, the system can re-allocate users by bringing them forward or moving them backwards. 
     With reference to  FIG.  4 C , it is demonstrated how the position of guests in a buffer queue may be reallocated. The two queues  201  and  206  are for the attraction as it is running normally. As the attendant  207  scans a group into the buffer queue  206 , the system  205  removes them from the virtual queue  204  and maintains a list  203  of those guests in the buffer queue  206 . As there is no need to scan the guest out of the buffer queue when they get onto or into the attraction, this queue will grow, though a pruning algorithm would keep it at say 10 times the expected length, to avoid it getting too long. 
     If the ride breaks down (or the wait time increases for any other reason), the guests in the virtual queue  201  can be provided a choice of other attractions  202  that they may rebook on. The list of guests is held in the virtual queue  204 . The wait time associated with each guest on the new ride would be configurable. Options for this would include but not be limited to the time that they have already waited subtracted from the length of the virtual queue that they are joining (either current length or the length at the time they originally reserved on the closed ride), or the time that they have yet to wait for the closed attraction. The system will track the number of guests allocated onto each ride to ensure that any one ride does not get too many. Another option is that the guest will be allocated an immediate access pass for the closed ride when it reopens, and are then free to book on another ride normally. 
     The attendant  207  will then scan the front of buffer queue  206 , this will determine the head of the queue in the list  203 , all guests after this point in the buffer queue can then be allocated a premium pass or similar for another ride. If there are multiple points that may be the head of the queue (e.g. a train that loads both sides) then the attendant will scan all possible heads and the system will then determine the list based on this. 
     A ride may close for a number of reasons and with subsequently different closure lengths. For scheduled stoppages (addition of a second or subsequent train for example) may be entered into the system beforehand, the system will then cause a gap in guests arriving to cater for this temporary stoppage. The throughput will then be adjusted accordingly after this stoppage so that a potentially different throughput of guests can then be accommodated. 
     For unexpected stoppages of short duration (e.g. ride cleaning), the buffer queue will grow during the stoppage, the system may attempt to push back some guests in the virtual queue. If guests are not delayed, then the buffer queue will grow in length. Since the throughput onto the buffer queue is set to be lower than the ride throughput, once the ride restarts the buffer queue will start to shrink. 
     For unexpected stoppages of a longer expected or unknown duration, the guests in the virtual queue may be reallocated by the system into queues for other rides (the group rides would be pre-set or set by an operator when the ride is marked as closed). Their new wait time may be set as the amount of time that they still have left to wait, or subtracting the amount of time that they have waited from the queue length of the new ride (either current or the length at the time that they reserved). The guests who have already scanned into a buffer queue will be out of the virtual queue. If there is no barrier for them to scan to get on the attraction then the system will keep a list of guests who have scanned in. The operator can then go to the guest at the front of the buffer queue (or multiple guests in the case of parallel loading) and scan their devices. The system may then assume that all guests after those scanned are in the buffer queue can then be immediately credited with a priority voucher within the system. 
     Enforcing a time limit on the window for the guest to ‘check in’ at the front of the line, the system can reduce the possible surges made by guests delaying their entry (lunch, another performance etc.) the guest in this case will be required to notify the server that they cannot arrive within their allotted window and select a later time when they will be able to arrive. 
     Different types of reservations will be treated in a priority order for this pull forward or push back—for example a timed purchased ticket will be pushed back after a non-purchased reservation. 
     A line closure will have the same effect (pre-empting the signalling of the buffer queue becoming too long). 
     When a ride closes the guests can be proactively managed, and reassigned (with the guest getting a choice) into virtual queues on the remaining rides. Those in the buffer queue can be credited with an immediate (front of line) pass to use elsewhere, removing some of the customer complaints and the need for the guest to complain to guest services to get some form of recompense. 
     With reference to  FIG.  4 D , it is demonstrated how a queuing system according to one or more embodiments and/or aspects described herein may be operated with multiple virtual queues in parallel. When the system manages 100% of the line, multiple queues  501 ,  502  may be configured whose individual throughputs will add up to the available throughput. The parameters of these queues may be set differently. In this example the second queue  502  provides a premium allocated ticket which does not count towards the guest&#39;s concurrent ride reservation limit. In this case the tail of the queue  504  is the time that is suggested to the guest when they purchase a timed reservation, though they are free to select a time later  503  if they have already planned something else at the time suggested. 
     Such a system may allow priority guests who have received an entitlement to the priority queue through some means, which may include paying for the entitlement, as a frequent user bonus, or being granted as a function of other parameters. 
     These additional queues can be run as fixed wait time queues or virtual queues where the length is dependent on the throughput allocated and the number of guests who have booked. 
     Each queue has separate parameters to determine the queue type as well as the throughput. Priority queuing may be sold into a second queue providing a fixed time, which allows the guest to carry on using the system for other rides. 
     By providing a virtual queue online, with an optional priority queue line in parallel the guest is freed from waiting in line and the merge point of the two queues is itself virtual so guest A who is in the standby line presents themselves or their group at the front at the same time as guest B who is in the priority line, neither will have any idea how long the other has waited. 
     Although a preferred embodiment has now been explained, the skilled person will understand that various alternatives and modifications are possible. For instance, although this system has been largely described with reference to an amusement park, it may equally be applied to other attractions or resources in which a time of access or entry may be desirable, such as a museum, a shop, an office counter, a restaurant or another appointment-based attraction or resource. 
     As noted above, throughput for the attraction may be measured by counting people moving through the access point. An alternative approach for measuring throughput is also considered. A wireless beacon may be placed at either end of the physical queue. Then, as a user with a wireless device that can interface with the beacon passes it, the device records the time. The device also records the time when it passes the end of the queue. It can then transmit this to a server. An advantage of this approach is that the queue ends can be moved easily and need no power or networking, which is instead reliant on the user device. The system may only need to measure a proportion of the guests rather than 100% to extract the necessary information (for instance, it may know how many have gone into the queue as they have been scanned previously). 
     System Configuration 
     Referring next to  FIG.  5   , there are schematically illustrated interactions between user devices and a system operated in accordance with the disclosure. In this embodiment, there are provided: a smartphone access key  401 ; a kiosk  402 ; an alternative access key  403 ; an access barrier  404 ; a scanning device  405 ; a management console  406 ; a (computer) server (also referred to as a system)  407 . A communications network (or connectivity)  408  provides connectivity between the various components of the system. The management console  406  may be used by the operator of the attraction or attractions to configure the server  407  appropriately. 
     To use the system the guest first registers, which can be done using a personal communications device  401  (such as a mobile telephone) or at a kiosk  402 . For a premium system this will include payment of the premium service level fee. For a system where all guests are required to use the system to book, a method of permitting that each guest only appears once is required. Typically this will be based on the entry ticket, where the ticket has a unique identifier for that guest or group. The system will allow that an entry ticket may only be used for one session in a day. Multiple entry tickets will enable a guest on subsequent visits to register their session. 
     A form of identification links each user to a device used to interact with the system, which is typically the smartphone access key or device  401  discussed above or an alternative type of access key  403 , which will be discussed below. A link to the host system to validate and verify the ticket will reduce potential fraud of guests entering invalid tickets. If this system also provides information as to whether the ticket has been used that day to gain access to the park (that is, the guest is inside the park) this will provide a further level of security. A guest may register on their personal communication device  401 ; alternatively they may use an alternative static form of access device  403  (such as a paper ticket with an identifier such as a barcode, QR or other visual code, an RFID device, a short range wireless communications device such as based on Bluetooth or similar technologies or biometric) and register at a kiosk  402 . This may allow each user of on the system  407  to be linked to a unique identifier for the guest in the form of their access key. 
     To register at a kiosk  402 , the user presents their access key (either the smartphone  401  or the alternative access key  403 ) as well as their tickets (not shown). The kiosk  402  comprises a reader for the smartphone  401  and/or the alternative access key  403 . The tickets are then associated with the access key into a session. 
     To register on a personal communication device  401 , the guest can either use the device as the access key, or associate a different access key with the session and present the tickets of the group to associate these with the session (either by scanning or typing the ticket in). This can be done directly from the personal communication device  401 , in particular over a network connection. 
     Where the tickets have been bought online in advance, the session containing the tickets and the access key of the guest may be passed by the ticket engine to the system to pre-create these sessions. In this case, the guest identifies themselves with the system and their session is then retrieved. 
     The system  407  provides at least one virtual queue per attraction. However, some attractions may have multiple virtual queues. In this case, one of the virtual queues for an attraction may be considered a normal virtual queue and at least one other virtual queue for the attraction may be considered a premium virtual queue. The throughput for the normal virtual queue and the premium virtual queue for the same attraction may be different and the throughput for the premium virtual queue would normally be higher than that of the normal virtual queue. 
     Generally, a guest will only queue in one normal virtual queue at a time. The system may provide an enhanced service level generally through payment of a fee so that additional queue places may be added to their list. These are typically of the form of single or limited visits to an attraction, multiple attractions or faster access to one or more attractions. By providing a second virtual queue with different parameters the guest will get a time to go to the additional attraction. This will not stop them using the main system to queue and visit attractions whilst this additional entitlement remains on their list. 
     To make a reservation: On a personal communication device  401  (where the guest remains logged in during the visit), they select from the options available on the screen which then communicates the preferences to the server. OR At a kiosk  402 , the guest presents an access key in the form of a personal communication device  401 , or alternative access key  403 , such as an RFID device or media, a ticket or biometric information to retrieve their session details which are then presented on the kiosk  402  screen. The kiosk  402  presents the guest with options similar to the smartphone  401 , enabling them to make a choice. Where appropriate, this information is then loaded onto an access key, the guest representing their access key for the system to write the information to it. 
     To reserve a time, a guest will be presented with a list of the attractions and the predicted ride time. When they reserve, the system will check the current queue, add them to the end of it and notify them of the actual time that has been reserved for them. The guest may be free to alter this time to be later than that supplied by the system  407 . This will enable the guest to plan other events if required, especially for purchased allocation. 
     In addition to the reservation for attractions, additional benefits may be made available for guests to purchase, which may enable timed access to attractions. These can be individual or grouped. These may be managed by adding a separate virtual queue for the attraction. 
     Guests may purchase access to some of the rides in advance, allowing them to ensure that during their visit they are guaranteed a ride on those that they want. The number of rides providing this will be determined by the system setup and packages available. 
     Packages for reserving additional rides may be available for purchase, or for credit to the guest&#39;s session at guest services discretion. A group of rides may be available from which the guest may only be allowed on a subset. 
     The guest may opt to ‘step out of the line’ to perform certain activities; in this case their position remains fixed. This allows them to maybe use the booking engine for something different, but without having to cancel their reservation and so re-joining the line at the end. Additionally or alternatively, the system may force the guest to do so, if the guest wants to do something else (for example due to a last minute reservation for another attraction, or a longer event such as lunch, a show or similar). 
     During normal operation, the queue management system  407  allocates a number of guests per unit of time (for example, a minute) that the ride can accommodate, each unit of time or ‘bucket’ will get filled with guests, then the next bucket will be filled. If a group is larger than the bucket, then the subsequent bucket or buckets will have a corresponding number subtracted from them. 
     One other alternative setup for the management of this 100% virtual queue system is for attractions that need or can cope with smaller buffer queues, as will now be discussed. 
     The system monitors the people going through the access point, from this determines the average throughput. This will be combined with past data and smoothed to avoid large changes. 
     Based on this throughput the wait times are calculated for all guests in the queue. When these wait times have changed by a pre-set margin, the guest will be notified of the change. 
     The guest is therefore not presented with a fixed visit time, but with an estimate, which will get more accurate the nearer to the front of the queue that they get. The guest can choose to revert to their original later time if they are unable to make the new estimated time. 
     By setting the throughput initially as a proportion of the expected throughput the reservation time should in normal running be brought forwards. In the event of ride closures the updated reservation times will be pushed out, for extended closure the system will offer them a choice of switching to another queue. 
     This system copes better with low throughput attractions where the throughput is more variable, so a fixed reservation time cannot be easily provided. 
     Guests may be grouped into priority groups, so that higher priority groups take precedence in being moved forwards, and become the last to be moved back. 
     When the guest arrives at the access barrier  404  at the time set by the server  407 , the scanning device  405  detects the smartphone access key  401  or the alternative access key  403 . The guest is allowed to pass through the access barrier  404  towards the attraction if the scanning device  405  (optionally after checking with the server  407 ) confirms that the guest is entitled to do so based on the time set by the server  407 . The scanning device  405  may be integrated with the access barrier  404 , so that the opening of the access barrier  404  is automatic. Alternatively (as shown), an attendant may be present to use the scanning device  405  and open the barrier based on the result. 
     The throughput of guests into the buffer queue can be adjusted so that normally it will be below the actual throughput of the ride. The factor will be determined operationally and will take into account: the variability of throughput of that ride; the propensity of the ride to break down, or other unanticipated stoppages; and/or the propensity of other rides within the park to break down or have stoppages (planned or unplanned) resulting in temporary closure and thus the potential need to offload guests. 
     To manage a line or lines efficiently, in every case where the throughput of the service or attraction can vary, the system must manage this virtual queue and keep the guest updated with their time to present themselves. This can be achieved by either moving the entry time forwards or backwards, or by sending a message to those with a personal device to determine whether they would accept a place sooner. 
       FIG.  6    illustrates an exemplary computing system  500  that may be used to implement one or more embodiments and/or aspects described herein. For example, any of the computer systems or computerized devices described herein may, in at least some cases, be a computing system  500 . The computing system  500  of  FIG.  6    includes one or more processors  510  and memory  510 . Main memory  510  stores, in part, instructions and data for execution by processor  510 . Main memory  510  can store the executable code when in operation. The system  500  of  FIG.  6    further includes a mass storage device  530 , portable storage medium drive(s)  540 , output devices  550 , user input devices  560 , a graphics display  570 , and peripheral devices  580 . 
     The components shown in  FIG.  6    are depicted as being connected via a single bus  590 . However, the components may be connected through one or more data transport means. For example, processor unit  510  and main memory  510  may be connected via a local microprocessor bus, and the mass storage device  530 , peripheral device(s)  580 , portable storage device  540 , and display system  570  may be connected via one or more input/output (I/O) buses. 
     Mass storage device  530 , which may be implemented with a magnetic disk drive or an optical disk drive, is a non-volatile storage device for storing data and instructions for use by processor unit  510 . Mass storage device  530  can store the system software for implementing one or more embodiments and/or aspects described herein for purposes of loading that software into main memory  510 . 
     Portable storage device  540  operates in conjunction with a portable nonvolatile storage medium, such as a floppy disk, compact disk or Digital video disc, to input and output data and code to and from the computer system  500  of  FIG.  6   . The system software for implementing one or more embodiments and/or aspects described herein may be stored on such a portable medium and input to the computer system  500  via the portable storage device  540 . 
     Input devices  560  provide a portion of a user interface. Input devices  560  may include an alpha-numeric keypad, such as a keyboard, for inputting alpha-numeric and other information, or a pointing device, such as a mouse, a trackball, stylus, or cursor direction keys. Additionally, the system  500  as shown in  FIG.  6    includes output devices  550 . Examples of suitable output devices include speakers, printers, network interfaces, and monitors. 
     Display system  570  may include a liquid crystal display (LCD), a plasma display, an organic light-emitting diode (OLED) display, an electronic ink display, a projector-based display, a holographic display, or another suitable display device. Display system  570  receives textual and graphical information, and processes the information for output to the display device. The display system  570  may include multiple-touch touchscreen input capabilities, such as capacitive touch detection, resistive touch detection, surface acoustic wave touch detection, or infrared touch detection. Such touchscreen input capabilities may or may not allow for variable pressure or force detection. 
     Peripherals  580  may include any type of computer support device to add additional functionality to the computer system. For example, peripheral device(s)  580  may include a modem or a router. 
     The components contained in the computer system  500  of  FIG.  6    are those typically found in computer systems that may be suitable for use with one or more embodiments and/or aspects described herein and are intended to represent a broad category of such computer components that are well known in the art. Thus, the computer system  500  of  FIG.  6    can be a personal computer, a hand held computing device, a telephone (“smart” or otherwise), a mobile computing device, a workstation, a server (on a server rack or otherwise), a minicomputer, a mainframe computer, a tablet computing device, a wearable device (such as a watch, a ring, a pair of glasses, or another type of jewellery/clothing/accessory), a video game console (portable or otherwise), an e-book reader, a media player device (portable or otherwise), a vehicle-based computer, some combination thereof, or any other computing device. The computer system  500  may in some cases be a virtual computer system executed by another computer system. The computer can also include different bus configurations, networked platforms, multi-processor platforms, etc. Various operating systems can be used including Unix, Linux, Windows, Macintosh OS, Palm OS, Android, iOS, and other suitable operating systems. 
     In some cases, the computer system  500  may be part of a multi-computer system that uses multiple computer systems  500 , each for one or more specific tasks or purposes. For example, the multi-computer system may include multiple computer systems  500  communicatively coupled together via at least one of a personal area network (PAN), a local area network (LAN), a wireless local area network (WLAN), a municipal area network (MAN), a wide area network (WAN), or some combination thereof. The multi-computer system may further include multiple computer systems  500  from different networks communicatively coupled together via the internet (also known as a “distributed” system). 
     While various flow diagrams provided and described above may show a particular order of operations performed by certain embodiments and/or aspects described herein, it should be understood that such order is exemplary. Alternative embodiments may perform the operations in a different order, combine certain operations, overlap certain operations, or some combination thereof. 
     The foregoing detailed description of the technology has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the technology to the precise form disclosed. Many modifications and variations are possible in light of the above teaching. The described embodiments were chosen in order to best explain the principles of the technology, its practical application, and to enable others skilled in the art to utilize the technology in various embodiments and with various modifications as are suited to the particular use contemplated. It is intended that the scope of the technology be defined by the claim. 
     User Interface 
       FIG.  7 A  illustrates a map user interface that identifies estimated wait times for multiple attractions on a distorted map of a venue. The map user interface is illustrated in  FIG.  7 A  being displayed via a display screen of a front-end device  305 , which is illustrated as a mobile device  110 . 
     The map user interface of  FIG.  7 A  includes a distorted map  315  with a guest location marker  340  and a number of markers identifying estimated wait times for various points interest. For example, different points of interest marked on the map  315  are illustrated in  FIG.  7 A  as having 5 minute wait times, 10 minute wait times, 15 minute wait times, or 20 minute wait times, depending on the lines outside each point of interest. 
     The map  315  of  FIG.  7 A  is distorted in that it is not illustrated entirely to scale. In particular, certain areas may be illustrated at a closer scale (i.e., more “zoomed in”) than other areas. For example, in the map  315  of  FIG.  7 A , an area including the guest location marker  340  and the point of interest location markers is illustrated at a closer “more zoomed in” scale (e.g., a 1:10 scale), while areas of the entertainment venue that are farther away from the guest location marker  340  and the point of interest location markers are illustrated at a farther “more zoomed out” scale (e.g., a 1:100 scale). Each “area” may be of uniform scale, or may have a gradual increase/decrease in scale internally, or some combination thereof. 
     An area including guest location marker  340  and point of interest location markers could gradually have a farther “more zoomed out” scale towards the edges of the area. The areas could be segmented internally as well. For example, a sub-area including the guest location marker  340  may be illustrated at a closer scale (e.g., a 1:5 scale) than an area including the point of interest location markers (e.g., a 1:15 scale), or vice versa. It should be noted that while  FIG.  7 B  illustrates the map  335  as distorted, in some cases, it may instead be an ordinary map illustrated entirely at one scale. 
     The map user interface of  FIG.  7 A  also includes an application navigation element  310 . This identifies that the current user interface is the “map” user interface, includes a search function  320  allowing a user of the front-end device  305  to search through the map for a particular point of interest, includes a specifier  330  that identifies that the points of interest currently shown on the map are “rides” as opposed to restaurants or bathrooms, and includes a filter function  335  allowing a user of the front-end device  305  to further filter the types of points of interest shown (e.g., scary roller-coaster rides, child-friendly rides). The application navigation element  310  of  FIG.  7 A  also includes a menu button  320  allowing further navigation within the application (e.g., to reach the list user interface illustrated in  FIG.  7 C ). 
       FIG.  7 B  illustrates a pop-up alert displayed over a map user interface, the pop-up alert identifying an estimated wait time and various facts about a particular attraction in a venue. The pop-up alert  350  and map-user interface are illustrated in  FIG.  7 B  being displayed via a display screen of a front-end device  305 , which is illustrated as a mobile device  110 . 
     The pop-up alert  350  of  FIG.  7 B  is overlaid over the map user interface  315  of  FIG.  7 B , which is darkened to put the emphasis on the pop-up alert  350 . This darkened map user interface  315  of  FIG.  7 B  may or may not retain ordinary map functionality or interactivity while the pop-up alert  350  remains displayed. For example, panning, zooming, or selecting different points of interest may be disabled while the pop-up alert  350  remains displayed. The pop-up alert  350  of  FIG.  7 B  includes a point of interest name (“Race For Your Life Charlie Brown”), a photo of the point of interest, some details  355  (identifying the ride as a “thrill” ride, identifying a 42 inch height requirement, and identifying a under-41-inch guardian supervision requirement), and an estimated wait time (10 minutes). The pop-up alert  350  of  FIG.  7 B  also includes navigation buttons, including an information button  360  that navigates the user to a point of interest information user interface (e.g., such as the one illustrated in  FIG.  8   ), a ticket button  365  that navigates the user to an electronic copy of their tickets (e.g., and in some cases may alert the user to available promotions), and a travel map button  370  that navigates the user to a map with travel directions (e.g., walking directions, bus directions, trolley directions, driving directions, or some combination thereof) to the identified point of interest. 
     The map user interface in the background of  FIG.  7 B  also includes the application navigation element  310  of  FIG.  7 A . 
       FIG.  7 C  illustrates a list user interface identifying estimated wait times and various facts about multiple attractions in a venue. The list user interface is illustrated in  FIG.  7 C  being displayed via a display screen of a front-end device  305 , which is illustrated as a mobile device  110 . 
     The list user interface of  FIG.  7 C  includes a list element  375  identifying one ride named “The Beast.” The list element  375  identifies a 10 minute estimated wait time, and includes details  355  identifying “The Beast” ride as “scary” and as having a 48 inch height requirement. The list element  375  also includes a ticket button  360  and a travel button  370 , as well as an information button  365  that navigates to the point of interest information user interface illustrated in  FIG.  8   . 
     The list user interface of  FIG.  7 C  includes a list element  380  identifying one ride named “The Backlot Stunt Coaster.” The list element  380  identifies a 10 minute estimated wait time, and includes details  355  identifying “The Backlot Stunt Coaster” ride as “scary” and as having a 48 inch height requirement. The list element  375  also includes a ticket button  360  and a travel button  370 . 
     The list user interface of  FIG.  7 C  also includes an application navigation element  310  similar to the application navigation element  310  illustrated in  FIG.  7 A , though the application navigation element  310  of  FIG.  7 C  identifies that the current user interface is the “list” user interface, and the search function  325  and filter function  335  are applied to searching for points of interest within the list and filtering the points of interest viewable within the list, respectively. The menu  320  of  FIG.  7 C  may be used to return to the map user interface of  FIG.  7 A . 
       FIG.  8    illustrates a point of interest information user interface identifying an estimated wait time graph and other facts about a particular attraction in a venue. The point of interest information user interface is illustrated in  FIG.  8    being displayed via a display screen of a front-end device  305 , which is illustrated as a mobile device  110 . While front-end device  450  of  FIG.  8    is illustrated in an exaggerated manner with a vertically lengthy display, it should be understood that the proportions of the front-end device  450  could be closer to those of exemplary front-end device  305 , and that the notification user interface of  FIG.  8    could include a scroll bar or other scrolling mechanism to scroll through the notification user interface of  FIG.  8   , for example via touchscreen gestures, mouse movements, mouse clicks, scroll wheel/ball movements, or some combination thereof. 
     The point of interest information user interface of  FIG.  8    includes an application navigation element  410  that identifies that the current user interface is a point of interest information user interface (“POI Info”) and allows the user to navigate back to a map user interface, such as the map user interface of  FIG.  7 A . In another embodiment, the application navigation element  410  of  FIG.  8    could instead allow the user to navigate back to a list user interface, such as the list user interface of  FIG.  7 C . 
     The point of interest information user interface of  FIG.  8    also includes an image  415  of the point of interest, which in this case is the ride “The Beast,” as explained in the name segment  420 , which also identifies the wait time (10 minutes) and a summary of the ride (“Experience what it&#39;s like to be a stunt car driver as your car races out onto the track and transports.”) The point of interest information user interface of  FIG.  8    also includes a buttons section  425  with a ticket button  365  and a travel button  370 . The point of interest information user interface of  FIG.  8    also includes a height requirement information section  430  identifying a 42 inch height requirement and identifying a guardian supervision requirement for guests from 38 inches to 41 inches in height. 
     The point of interest information user interface of  FIG.  8    also includes an estimated wait time graph  435 . This is generated by the application server(s)  125  using the wait time calculation algorithm as described in reference to  FIG.  3   , and includes future wait times so that the guest in question can plan when they wish to get on the “Beast” ride. For example, 1 pm-2 pm is predicted to have low wait times, but 3 pm-5 pm is predicted to have high wait times, so a guest might use this to plan to ride the “Beast” ride around 1:30 pm. Similarly, venue staff might use this type of estimated wait time graph  435  to plan an appropriate reaction to alleviate potential problems before they become real problems. For example, venue staff may act to increase guest throughput by increasing the number of staff or cashiers. Venue staff might also act to increase capacity by increasing a number of seats for a show or increasing a number ride cars operating on a theme park ride. Such venue staff actions may be planned ahead of time during estimated peak times, such as 3 pm-5 pm as identified in  FIG.  8   . 
     The point of interest information user interface of  FIG.  8    also includes a mini-map  440  that identifies a location  445  of the “Beast” ride within a map showing a portion of the venue. The mini-map  440  may be distorted as discussed regarding the map  315  of  FIG.  7 A , or may be an ordinary map drawn to scale. 
     Although a preferred embodiment has been described above, the skilled person will understand that various alternatives and modifications are possible. For instance, although this system has been largely described with reference to an amusement park, it may equally be applied to other attractions or resources in which a time of access or entry may be desirable, such as a museum, a shop, an office counter, a restaurant or another appointment-based attraction or resource.