Automation, Controls

Improving wayfinding in complex environments: The case for dynamic signage

The increasing sophistication of automated building systems has allowed for opportunities in the improvement of wayfinding using dynamic signage in complex, changing environments.
By Andrew Biery, PE, Arup, New York City July 20, 2018
Figure 2: Dynamic signage indicates a compromised egress route. Courtesy: Arup

Learning objectives

  • Understand the limitations of traditional static signage and how it can be improved.
  • Know the key elements and mechanics of dynamic signage.
  • Learn how dynamic signage can improve wayfinding in complex or unique environments.

Exit marking has been an important part of life safety design since the 1930s, when the NFPA created a committee on life safety and began developing strategies for occupant egress in response to the 1911 Triangle Shirtwaist Fire in downtown Manhattan. Only minor changes have been made to standard exit signage and exit marking since then, despite improvements and increased sophistication of building technologies.

Dynamic signage offers many new improvements to wayfinding and goes beyond what traditional static signage offers in complex and unique environments.

Traditional versus dynamic signage

Standard practice as defined in NFPA 101: Life Safety Code, the International Building Code (IBC), and the International Organization for Standardization (ISO) 7010 typically dictate that effective wayfinding performance is dependent on visual-spatial features including simplicity, occupant familiarity with the building, visual access, proper signage, and architectural features. Standard signage is obviously an important architectural feature for exit identification, but multiple factors can decrease its effectiveness. Designers often make assumptions based on conventional buildings that do not consider the complexity of a nontraditional design. In these cases, traditional exit signage may not meet the designer’s intent where occupant reaction to alarms may differ from that in a more traditional setting, occupants are unfamiliar with the building, or the route to the exit is more meandering than in a traditional design. Also, exit signage requirements in fire and building codes typically assume a more traditional design and do not consider a building’s complexity. Exit signage requirements are often static and do not differentiate between simple and complex buildings.

Traditional exit signage lacks the ability to adapt to changing environments or emerging threats that may occur in complex occupancies, such as airports, train stations, or other large assembly areas. What might be a safe, useable egress route at one time might be blocked or impaired during an emergency. Recent events have shown that these types of occupancies are increasingly becoming targets for terrorism and other types of attacks, leading to the increasing frequency of large-scale evacuations. Since 2010, there have been more than 25 reports of events necessitating full airport-terminal evacuation worldwide, largely due to security threats. In the U.S., reports of mass confusion and chaos were reported for separate incidents at the JFK Airport in New York in August 2016 and LAX Airport in Los Angeles in September 2016, showing that the exiting and wayfinding systems in place can be improved.

Figure 1: An open floor plan of Sky Central Building located in Isleworth, U.K., with several open stairs connecting multiple floors. Courtesy: Arup

Examining human behavior during an evacuation shows why traditional exit signage is not typically effective in reducing mass confusion during such events. Exit signs are routinely ignored during an emergency, with many occupants overlooking secondary egress routes and exiting through the route in which they entered the building. This phenomenon is especially pronounced in buildings where occupants are unfamiliar with the building and exit locations. Studies have suggested that occupants involved in a fire emergency, who may have high stress levels and are attempting to process large amounts of information quickly for self-preservation, will often filter out information regarding exit signs that would have helped them reach the closest exit. Many occupants will not actually perceive exit signs in their field of vision due to what has been called “learned irrelevance,” in which people continually exposed to a visual cue for which they would not ordinarily respond to are cognitively trained to ignore the cue.

Research has also demonstrated that more detailed instructions with specific locations on exit locations can have a significant impact on lowering egress times. One investigation commissioned by the University of Venice and the University of Padova in Italy compared the behavior of occupants when trying to reach an area of refuge when given no instructions, versus occupants that were given detailed instructions. Occupants not given instructions tended to egress toward the familiar route through which they entered the building. Occupants shown specific signs indicating the location of the area of refuge could promptly identify the proper direction and begin to move toward it. The study confirms that giving specific instruction creates a change in evacuation behavior toward using a more effective exit path over using the most familiar route.

Intelligent active dynamic signage can provide a solution to the learned irrelevance problem while also providing specific instructions or exit cues in a way that traditional exit signage cannot. By its nature, a dynamic sign that is constantly updated with new information is expected to grab the attention of occupants more effectively than a static sign that occupants have been cognitively trained to ignore. Also, an effective dynamic signage system will gather information on the conditions in the building, including the presence of hazardous conditions that may block an egress route. The system can then redirect occupants in real time to the most effective exit locations.

Dynamic signage examples and applications

The Getaway project, funded under a transport initiative sponsored by the European Union, has shown the effectiveness of intelligent signage through research, development, and full-scale evacuation trials. The project created and evaluated a system that uses the traditional ISO 7010 Standard green exit signage, but adds a dynamic element by activating a flashing cycle during an emergency while also updating the indicated direction of travel based on an intelligent building-information collection system and evacuation software. The software identifies the optimal evacuation route for the population and then updates the dynamic exit signage accordingly to direct occupants in the proper direction. Also, any exit routes that are considered dangerous due to perceived hazards are shut down by negating the emergency exit signs pointing in the hazardous route direction.

The Getaway project organized experimental studies with the goal of testing the ability of occupants to accurately perceive and interpret the information being conveyed by the system, while also comparing the detectability of the dynamic signage system to that of traditional exit signage. The initial trials were performed at Queen Anne Court at the University of Greenwich, London, where occupants unfamiliar with the building were placed at a certain point and told to exit using a route of their choice. An identical study examining the effectiveness of traditional signage had previously been performed in the same building, providing a baseline comparison for the dynamic signage results.

Figure 2: Dynamic signage indicates a compromised egress route. Courtesy: Arup

On the issue of learned irrelevance and occupant perception, data from trials indicate that the intelligent signage system provides a significant improvement. Sign perception more than doubled for dynamic signage than in the traditional signage study, and all occupants who perceived the sign chose to walk in the direction indicated. The study shows that egress times can be reduced with dynamic signage, as the average decision time of those who did not detect any signage was 217% longer than those who detected signage. The data also suggest that the decision time for dynamic signage was improved over that of traditional signage.

Full-scale trials were performed as part of the Getaway initiative at train stations in London and Barcelona, Spain, provided additional validation on the effectiveness of dynamic signage. For a baseline case trial using traditional exit signage, nearly all occupants moved toward the nearest exit, which may not have necessarily been deemed a safe exit. With the intelligent signage system in place, 66.4% of occupants used the safe exit indicated by the system. In addition, 57.3% of participants located near a nonviable exit followed the directions of the dynamic system to reach a safe exit. The results indicate a significant improvement in directing occupants away from hazardous situations and toward secure exit routes.

Emergency dynamic signage systems have also been adopted in several real-world applications including at Sky Broadcasting Campus in Isleworth, U.K. The 3-story campus building consists primarily of open-plan offices on levels 2 and 3 with communal restaurant and cinema areas intended for use by the office occupants on the ground floor. Each floor is interconnected with a series of open stairs, with no enclosed stairs or protected routes used as part of the egress strategy. With occupant loads of up to 2,970 on the upper floors, consideration had to be given to a large simultaneous evacuation in which open-stair egress routes would be compromised. Computational fluid dynamics (CFD) modeling showed that multiple open stairs may be compromised during a fire in certain locations, but that multiple alternative routes were readily available throughout the simulation. To assist building management in directing occupants away from hazardous areas, dynamic signage was placed at the entrance to the open stairs. The signage is connected to the fire command center, where management can monitor the location of fire conditions via the smoke-detection system and manually activate “do not enter” signs. (See Figure 1).

The Pentagon in Washington, D.C., uses a dynamic signage system that was developed in response to the Sept. 11 attacks. The system is linked to a real-time building-evacuation model used to optimize egress routes in the event of an emergency. Frankfurt International Airport also uses a sophisticated dynamic signage system to improve wayfinding and reduce overcrowding at checkpoints in the terminal.

Dynamic signage system components

Convincing occupants to perceive and follow the direction of dynamic exit signage is an important factor when installing such a system. But the effectiveness of the system will be dependent on providing adequate directions during an emergency. A robust dynamic signage system will consider and react to current and changing conditions within the building. The following components should be considered in the design, depending on the system’s goals and complexity.

  • Fire detection and alarm system: The detection system collects data on potentially hazardous areas in the building so that egress routes can be updated accordingly. As the central and controlling component of the overall emergency system of the building, the alarm system also can be used to receive signals from the decision-maker and update signage accordingly.
  • Occupant-counting system: If overcrowding at exits or specific locations is a concern, a live feed through an existing closed-circuit television (CCTV) system can be used to quickly gather data on occupant whereabouts. Alternatively, gate counters or cell phone-detecting technology can be used for this purpose.
  • Intelligent analysis: Although not required, an intelligent software component can be added to the system to assist the decision-making process, using data collected from the detection and CCTV systems. Existing software will perform evacuation simulations based on predefined evacuation scenarios, using a variety of methodologies that vary in complexity-from basic algebraic correlations to agent-based modeling software that considers the interactions and motivations of individual people. The results of these simulations are then compared with the information collected by the fire alarm and CCTV system to rank and optimize egress routes. An important factor to consider for the intelligent-analysis portion of the system is processing power. In addition to providing accurate results, the system must be capable of performing simulations quickly enough such that the information is still useful and current during an evacuation.

The building data must be shown to a trained operator in charge of directing the building evacuation, who can then choose to activate the dynamic signage during the evacuation. In an airport terminal building or train station, control of the dynamic signage system should be installed in the fire command center, operations control center, or other location together with fire alarm-monitoring equipment.

The system can also be designed for situations where the fire detection or CCTV systems may not necessarily automatically identify hazardous egress routes. In the event of terrorism, an active shooter event, or another security emergency, the interface module (IM) interface can be used to indicate that all egress routes traveling toward the incident area must be avoided. The dynamic signage system must be capable of clearly communicating that certain egress routes are blocked or unsafe for this function to be effective. Figure 2 shows one such example of how this information may be relayed to the occupant.

Although research has shown intelligent dynamic signage as an effective tool in improving wayfinding and egress during an emergency, its use is still not widespread and has not been adopted by many building codes and standards. Therefore, developers and project stakeholders must still consider existing code requirements if choosing to use a dynamic signage system. Until building codes catch up to this new technology, the project team may choose to use traditional exit signage with the dynamic system as a supplemental life safety system.

If designed properly, an intelligent dynamic signage system can help solve many of the challenges presented by modern complex occupancies and emerging security threats. Research on early adoption of the technology presents compelling data indicating that the technology can identify optimal exits and improve wayfinding by conveying critical information to occupants more effectively. At a time when many other fire protection and life safety technologies are improving, consideration should be given for updating traditional exit signage where a more sophisticated approach is warranted.

Andrew Biery, PE, Arup, New York City
Author Bio: Andrew Biery is a senior fire engineer with Arup, where he has been a key contributor to the fire and life safety design for multiple projects involving large, public spaces including the New International Mexico City Airport and the Finch West Light Rail Transit project in Toronto.