Using Pedestrian Modelling to ensure safe distancing and interaction at the office

Though we have settled into a new normal, we know that people are generally looking forward to getting back to their office environment for the collaboration and social interaction. However, we also know that offices will look and function much differently than before we transitioned to working from home. Based on what we are reading from thought leaders in the space and what we are seeing being implemented, we can expect to see different seating arrangements, suggested movement patterns, and new policies and procedures for common areas.

Pedestrian modelling allows us to test these measures and evaluate their impact. Using our own office building and plans for returning to work as a starting point, we set up various models to quantify the mitigation measures that are likely to be implemented in the commercial sector.

Most commercial spaces will have two distinct areas that require careful planning: the office floors and the lobby. We have separated these because they involve different decision makers. Within the office floor, the tenant (or employer) is mainly in control of how that space is planned out and used. How their employees access this space is largely out of their control, although they can certainly engage with the property manager to inform those policies.

In the lobby, the property manager is responsible for safely moving people to and from their desired floors and for ensuring this process operates smoothly. Tenants can help make these procedures a success by communicating to the property manager what they anticipate for their employees’ arrival times and patterns.

Typical Office Floor

In the following example, we’ve assumed our business has divided into a “Blue Team” and a “Green Team” to optimize density in the office and ensure appropriate physical distancing. We analyzed seating locations and measured a radius that should be kept vacant. We refer to this as a static analysis of the seating arrangements. In our floor plan, this broadly translates into every other seat being occupied, which supports the two-team approach.

However, what the static analysis does not capture is the time component of how we use offices. Even if we can sit with a distance around us, it’s also important to understand how we move about the space. Attending meetings, going to the washroom, visiting colleagues, going to the kitchen; these are all aspects of office life that will not disappear after COVID.

In our model, we’ve assumed employees arrive to the office and select a random seat out of those available to their team, which becomes their assigned seat. Over the course of the day they will then randomly choose actions, such as visiting the washroom or the kitchen, then return to their seats for another period of time, and then repeat these behaviours. These are just examples of activities that have been included to capture the transient component of office life that the static analysis cannot quantify.

Now, we can test different mitigation measures. We first ran a baseline scenario, in which employees travelled unrestricted throughout the office (Model A), and then a refined scenario that introduced one-way corridors as a mitigation measure (Model B).

The model above can inform how effective certain mitigation measures are. For example, using a 30-minute sample period we quantified the total duration that employees were within a certain distance from anyone else. The goal of quantifying this metric is to compare the two options and determine if the mitigation measure does in fact improve the performance of the space.

The one-way corridors did in fact reduce the time employees spent in proximity to someone else, though we stress this is specific to the amount of transient movement that is expected and where people are going. This is something the client can help to inform. The value of this analysis will increase as floors become larger and more complex, since more interactions can be expected and more options for how to navigate that space become available.

Lobby

While planning for the office floors is a tenant responsibility, we expect that one of the biggest challenges for property managers is going to be effective and safe use of the lobby and other common areas. Mitigation measures, such as assigned queuing areas, reduced elevator capacity, and controlling where and how areas are accessed, can all help control the flow of people and ensure physical distancing. Staggered start times, alternating work weeks, and increased working from home are additional measures tenants can implement to reduce large surges of people arriving in the lobby.

Adding the lobby to our model above, we first determined the arrival volume (people per time period) that could be effectively handled by the available lobby space and infrastructure. This process is inherently stochastic since people arriving can head to any floor. We ran the model many times to capture this randomness and get an idea of what arrival volume is feasible given the proposed lobby strategies.

For buildings with more complex elevator systems, such as destination dispatch, this process will likely require the involvement of a specialized vertical transportation consultant to ensure the model accurately reflects real elevator processes. In the video below, the original lobby configuration with no mitigation measures is on the left (Model A). We then added a designated queuing area and allowed entrance from one location only (Model B).

The impact of the mitigation measures can also be quantified by “time in proximity” maps overlaid on the floor. The same two scenarios are shown below, the original lobby configuration and the lobby with mitigation measures in place.

Model A – Original Lobby

Model B – Mitigation Added

We can see that the mitigation measures in this scenario have effectively reduced congestion at the base of the elevators. However, this queuing also means it could take longer for tenants to reach their floor, which can be quantified to aid in decision making.

Summary

As we begin to plan our return over the coming months, we expect to see significant changes to how we use and navigate our workspaces. The models above illustrate an opportunity to quantify mitigation measures. They also present an opportunity for employers and property managers to demonstrate to employees and tenants how they have effectively planned for a safe return to work, offering peace of mind that the plan has been carefully thought through.

The models presented are indicative only as a proof of concept, and we would stress that performing this analysis for specific buildings or portfolios will require detailed discussions with the client to ensure appropriate input assumptions.

Lastly, we’ve added some references throughout to direct readers to other insightful articles on this topic, but this is hardly an exhaustive list. We are seeing more and more thought leadership coming from our peers in the AEC industry as we all tackle the challenges and opportunities presented to us by COVID, and we look forward to collaborating with others to develop these ideas and ensure a safe and efficient return to work.

For more information about pedestrian modelling or to connect and collaborate, reach out to Matt Smith.