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Building Occupant Egress Data (NIST Report of Test FR 4024)

These data are a contribution of the National Institute of Standards and Technology. The following reference should be included in any publication that uses or references the data

Kuligowski, E. D. and Peacock, R. D., "Building Occupant Egress Data," Report of Test FR 4024, Natl. Inst. Stand. Technol., Gaithersburg, MD (2010).

Data on people movement on stairs were collected from 9 office and residential building evacuations in the United States. The buildings involved in this study range from 6 stories to 62 stories in height. The data were collected by positioning video cameras out of the way of building occupants to record an overhead view of occupant movement in an exit stair during the evacuation. In most buildings, unless specified, the video cameras were placed on every other floor to capture a view of that floor’s main landing, the door into the stair at that level, and 2-3 steps on each side of the main landing (leading to and from the main landing). This camera placement allowed NIST to capture the times in which the occupant was seen moving past a particular floor landing as well as the time when he/she was seen moving into the stairs.

After video data was taken from each building evacuation drill, NIST recorded specific data from the videos into a spreadsheet format for each stair monitored during the drill. For each stair recorded, data were collected 1) for each occupant evacuating in that stair and 2) for each time during the evacuation drill that the occupant was seen at a specific floor in the stair (a camera position). The data collected for each occupant (overall) during the evacuation drill were the following information: occupant number, gender, floor of origin, whether he/she was carrying anything (Yes, No), his/her body size (less then ½ the stair, more than ½ the stair, or exactly half), whether he/she was alone or in a group during the drill, whether he/she was helping someone during the drill, and the floor on which he/she first seen. The data collected each time an occupant was seen on a specific camera were the following information: the time that he/she was seen entering the camera view, the time that he/she was seen leaving the camera view (see adjacent figure), his/her location on the stair (whether he/she was traveling on the inside, outside or the middle of the stair), and his/her handrail usage (whether he/she was using the inside or outside handrail, or both of them at the same time).

For all of the data, times are relative to the beginning of video recording for that location. Alarm times at each camera location are also included and again are relative to the beginning of video recording at each location.

In addition to the data collected from the videos, NIST also calculated the travel distances in between camera placements, including diagonal stair travel and horizontal corridors within the stair. To calculate the stair travel distances, the number of steps between floors, the riser/tread measurements of the steps, and the stair width are used. These data are also made available in the spreadsheet for each stair monitored during the evacuation drill.

From these data, researchers and practitioners can calculate movement speeds of people down stairs as a function of occupant density, travel distance, merging behavior, delay time, and door size. Additionally, analysis can be performed on individual delay or pre-evacuation times, handrail usage, body size, and counter-flow frequency (if any). The data collected from this study will improve the level of occupant safety in buildings.

People movement data from these evacuation drills are made available here in spreadsheet format. As of December 2009, NIST is releasing people movement data from four of the nine buildings observed; specifically Building 4 (two stairs), Building 5 (two stairs), Building 7 (four stairs), and Building 8 (one stair). One spreadsheet file is available for each stair observed, so there could be multiple files for each building observed (e.g., Building 7 will have four spreadsheet files since NIST observed four stairs in the building). The data contained in the spreadsheet are included in the following list.

Data taken for each occupant:

  • Column A: The code that indicates type of data in the current row of the spreadsheet: C for column headings, F for distances from floor to exit, and E for data collected for each evacuee.
  • Column B: The unique number assigned to each evacuee. Numbered from 1 to the number of unique evacuees identified from the original video record.
  • Column C: This column indicates the gender of the occupant. "M" is used for male, "F" for female, and a "?" may be included if the gender is not clear from original video record.
  • Column D: This column indicates, by an "x" in the spreadsheet, whether the evacuee was carrying anything during evacuation.
  • Column E: This column indicates, by an "M" in the spreadsheet for occupants that occupy significantly more than half the stair width during evacuation and by an "L" in the spreadsheet for occupants that occupy significantly less than half the stair width during evacuation. This may identify a possible obstruction to flow of other evacuees if the evacuee slows or stops during evacuation.
  • Column F: This column indicates, by an "x" in the spreadsheet, whether the evacuee was carrying an overcoat/jacket during evacuation.
  • Column G: The column indicates whether the evacuee was traveling with other evacuees throughout the evacuation. If the occupant was traveling with other evacuees, the others’ occupant number is listed in the spreadsheet.
  • Column H: This column indicates, by an "x" in the spreadsheet, whether the evacuee was assisting or being assisted by another evacuee during the evacuation.
  • Column I: This column indicates the highest floor in the stair where the evacuee was first observed on the original video record.
  • Column J: This column provides the occupant’s description, including hair color, clothing, and any items the evacuee carried during evacuation. This column is used to uniquely identify the evacuees during data collection. "LH/RH" labels are used to identify an occupant carrying something in the left hand or right hand and "LA/RA" labels are used to identify an occupant carrying something on the left arm or right arm.

 Data taken for each occupant at each camera location (Columns K through P are repeated for each camera location in the stair.):

  • Column K: This column indicates whether the evacuee descended the stair near the inside handrail, the outside handrail, or in the middle of the staircase.
  • Column L: This column indicates handrail usage by the evacuee. "I" indicates the use of the inside handrail, "O" indicates the use of the outside handrail, "B" indicates the use of both handrails, and "A" indicates alternating handrail use. If this column is blank, this may indicate either that the occupant did not use the handrail or that the handrail use could not be seen in the original video record.
  • Columns M and N: The time (from beginning of original video record) that the evacuee first entered the camera view on the current floor in minutes and seconds.
  • Columns O and P: The time (from beginning of original video record) that the evacuee left the camera view on the current floor in minutes and seconds.

In addition to the spreadsheet data (described above), each building is described below. Each building description includes information about the building layout and measurements, the evacuation drill and procedure, and specific data collection methods. With each building description are links to the individual spreadsheets for each stairwell in the building. The data is also available as a single ZIP file below.

Spreadsheets for all of the stairwells (.zip file)

Building 4 (West Coast of US)

Building 4 stairwell showing typical landing, stairs up and down from the landing, handrails, and doorway from building floor to stairwell. Photo Credit: NIST
Building 4 stairwell showing typical landing, stairs up and down from the landing, handrails, and doorway from building floor to stairwell.
Building 4 is a 24-story office building on the West Coast of the United States. The occupants in this building perform yearly staged evacuation drills; however, they participate in a full-building evacuation drill every five years. On a typical day, the building houses a population of approximately 1500 people. The building has two stairs; Stairs A and B. Stair A exits onto the 2nd floor lobby where occupants must travel through the lobby to exit the building. Stair B, on the other hand, exits directly to the outside on the ground floor (Floor 1). Both stairs are 1.12 m (44 in) wide (1.02 m (40 in) between handrails) and the individual steps measure 0.18 m (7 in) rise and 0.28 m (11 in) tread depth. NIST observed people movement in both Stairs A and B.

The travel distances between floors for each stair are provided in the spreadsheet files. In Stairs A and B, from floors 24 to 3, there are 20 steps between floors (interrupted by a mid landing 10 steps between floors). In Stair A between floors 3 and 2 (the exit floor), there are 30 steps between these floors (interrupted by two mid landings with 10 steps on either side of the landings). In Stair B in between floors 3 and 1 (the exit floor), there are 60 steps between these floors (interrupted by five mid landings with 10 steps on either side of the landings).

The evacuation drill observed by NIST took place in the spring months of 2008 during normal business hours (before lunch). 605 occupants participated in the unannounced full building evacuation drill (249 in Stair A and 356 in Stair B). During the drill, three firefighters traveled up Stair A to the 13th floor approximately 1.5 minutes into the evacuation drill. Also during the drill, fire fighters assigned to specific floors began floor searches to ensure that all occupants evacuated as soon as the alarm sounded.

On the day of the drill, NIST collected data from 23 different camera locations in the two stairs observed. In Stair A, 11 cameras were placed on every other floor beginning at the exit floor (Floor 2) and ending with Floor 22. Stair B, 12 cameras were placed every other floor beginning at the exit floor (labeled as P1), and then continuing on every other even floor from Floor 2 to Floor 22. For Building 4, the times of the occupants entering the camera view are taken 2-3 steps away from the main landing (leading to the main landing) and 3-4 stairs away from the main landing (leading away from the main landing). The variation in timing positions is due to the differences in camera views, i.e., some cameras were equipped with wide-angle lenses that could capture a higher number of steps in addition to the main landing. A wider angle view is shown in the adjacent figure, where the camera view shows 3 steps leading to the main landing and 4 steps leading away from the main landing.

Spreadsheet for Building 4, Stair A
Spreadsheet for Building 4, Stair B

Building 5 (West Coast of US)

Typical Building 5 stairwell Photo Credit: NIST
Building 5 stairwell showing typical landing, stairs up and down from the landing, handrails, and doorway from building floor to stairwell.
Building 5 is a 10-story office building on the West Coast of the United States. The occupants in this building practice yearly full-building evacuation drills. On a typical day, the building houses a population of approximately 1000 people. The building has two stairs; Stairs A and B, both of which exit directly out of the building on the first (or ground) floor. The two stairs are 1.27 m (50 in) wide (1.22 m (48 in) between handrails) and the individual steps measure 0.18 m (7 in) rise and 0.28 m (11 in) tread depth. NIST observed people movement in both Stairs A and B.

The travel distances between floors for each stair are provided in the spreadsheet files. In Stairs A and B, from floors 10 to 2, there are 22 steps between floors (interrupted by a mid landing 11 steps between floors). From floor 2 to 1 in Stairs A and B, there are 27 steps in between floor 2 and 1 (13 steps from floor 2 to the mid landing and then another 14 steps from the mid landing to the exit floor).

The evacuation drill observed by NIST took place in the spring months of 2008 during normal business house (before lunch). 804 occupants participated in the unannounced full building evacuation drill (436 in Stair A and 368 in Stair B). During the drill, six firefighters traveled up Stair B to the 7th floor approximately 8 to 11 minutes into the evacuation drill; i.e., when the drill was almost completed. Also during the drill, fire fighters assigned to specific floors began floor searches to ensure that all occupants evacuated as soon as the alarm sounded.

On the day of the drill, NIST collected data from 10 different camera locations in the two stairs observed. In Stairs A and B, 5 cameras were placed in each stair every other floor beginning at the exit floor (Floor 1) and up to Floor 9. For Building 5, the times of the occupants entering the camera view are taken 3-4 steps away from the main landing (leading to the main landing) and 4-6 stairs away from the main landing (leading away from the main landing). The variation in timing positions is due to the differences in camera views, i.e., some cameras were equipped with wide-angle lenses that could capture a higher number of steps in addition to the main landing. A wider angle view is shown in the adjacent figure, where the camera view shows 4 steps leading to the main landing and 6 steps leading away from the main landing.

Spreadsheet for Building 5, Stair A
Spreadsheet for Building 5, Stair B

Building 6 (West Coast of US)

Building 6 Landing Photo Credit: NIST
Building 6 stairwell showing typical landing serving two stairs, stairs up and down from the landing, and handrails separating landing for each stairwell. Landing is separated into two parts with two steps separating the parts.

Building 6 is a 62-story office building on the West Coast of the United States. On a typical day, the building houses a population of approximately 2800 people, 2/3 of which are below the 30th floor. The subdivision of office space varies from floor to floor. The building has four stairs available for egress though two of the stairs share a common shaft. There are transfer hallways in the buildings that route the egress stairs around mechanical spaces. NIST observed people movement in four of these stairs; specifically Stairs 5 (which served floors up to floor 52), 5A, and the two stairs that shared a common shaft, 6 and 6A (which served floors up to floor 52). For floors 52 and above, there are only two stairs. At the time of the drill, there were no occupants above floor 54.

All stairs were 1.05 m (40.75 in) wide and the handrails did not protrude into the stair width. The steps were 0.200 m (7.875 in) high and 0.254 m (10 in) deep. Most floors had 22 steps to the next floor, but the exact configuration varied (the number of intermediary landings varied from one to three). Stairs 5 and 5a had transfer corridors on floors 42, between 42 and 41 (5 only), 22, between 22 and 21 (5 only), and 4. For Stairs 6 and 6a, transfer corridors were located on floors 44, 24, 23 (6a only), 22 (6 only), 20 (6a only) and 4. In the 4th floor transfer corridor, the two stairs came together before separating again. The travel distances between floors for each stair are provided in the spreadsheet files. 

The drill took place on a 2008 spring morning during regular working hours before lunch.  Camera were placed several floors apart in the four different stairwells. A total of 607 occupants were observed over the approximately 20 min duration of the drill (participation in the drill was voluntary).

Spreadsheet for Building 6, Stair 5
Spreadsheet for Building 6, Stair 5A
Spreadsheet for Building 6, Stair 6
Spreadsheet for Building 6, Stair 6A

Building 7 (East Coast of US)

Typical Building 7 stairwell Photo Credit: NIST
Building 7 stairwell showing typical landing, stairs up and down from the landing, handrails, and doorway from building floor to stairwell.
Building 7 is an 18-story office building housed in three wings adjoining a fourth corridor at one end of the wings. The building houses approximately 4000 people and has twelve stairs available for egress, numbered one through twelve. NIST observed people movement in four of these stairs; specifically Stairs 1, 3, 7, and 12. These stairs were observed due to their placement in the building - it was important to observe stairs from different wings throughout the building. All four stairs were 1.12 m (44 in) wide (0.91 m (36 in) between handrails) and the individual steps measure 0.19 m (7.5 in) rise and 0.25 m (10 in) tread depth. Stairs 3, 7, and 12 exited to the lobby area on the fifth floor each through a 0.91 m (36 in) wide doors; while Stair 1 continued to the ground floor and exited directly out of the building.

The travel distances between floors for each stair are provided in the spreadsheet files. In Stair 1, there are 16 steps between floors (interrupted by a mid landing 8 steps between floors) from floors 18 to 4, and floors 3 to 2. In between floors 4 and 3 and 2 and 1, there are 18 steps between floors (interrupted by a mid landing 9 steps between floors). In Stairs 3, 7, and 12, there are 16 steps between floors (interrupted by a mid landing 8 steps between floors) from floors 18 to 6, and then a total of 19 steps in between floors 5 and 6 (9 steps to the mid landing and then 10 steps to the main landing/exit on floor 5).

In Building 7's history, there have been small fires and other incidents that initiated the building alarm. Additionally, the building practices fire drills on a yearly basis. Within the year before the observed drill, the local fire department noted one accidental alarm that initiated a building evacuation and one small fire that also initiated a building evacuation without injury to the occupants.

The evacuation drill observed by NIST took place in the spring months of 2008 during normal business hours (before lunch). Within the four stairs observed, 1084 occupants participated in the unannounced full building evacuation drill (255 in Stair 1, 292 in Stair 3, 340 in Stair 7, and 197 in Stair 12). During the drill, a total of 17 firefighters traveled up Stair 12 from the 5th floor to the 12th floor; one group of seven fire fighters were followed by another group of ten. Also, the local area Community Emergency Response Team (CERT) members stood at the entrance to Stair 2 and relayed to building occupants that Stair 2 was blocked and they needed to find another stair (likely causing a higher number of occupants to use the stairs near Stair 2 - Stairs 1 and 3 - than normally expected during an evacuation). Last, a person from the CERT team evacuated via Stair 7 assisted by three members of the fire department using an evacuation chair (or stair descent device).

On the day of the drill, NIST collected data from 30 different camera locations in the four stairs observed. In Stairs 3, 7, and 12, 7 cameras were placed every other floor beginning at the exit floor (Floor 5) and ending with Floor 17. In Stair 1, 9 cameras were placed every other floor beginning at the exit floor (Floor 1) and ending with Floor 17. For Building 7, the times of the occupants entering the camera view are taken 2 steps away from the main landing (leading to the main landing) and 3 stairs away from the main landing (leading away from the main landing). The adjacent figure shows a sample stair from building 7.

Spreadsheet for Building 7, Stair 1
Spreadsheet for Building 7, Stair 3
Spreadsheet for Building 7, Stair 7
Spreadsheet for Building 7, Stair 12

Building 8 (East Coast of US)

Typical Building 8 stairway Photo Credit: NIST
Building 8 stairwell showing typical landing, stairs up and down from the landing, handrails, and doorway from building floor to stairwell. Red and green lines are included to show points of data collection for occupants entering (green) and leaving (red) camera view.
Building 8 is a 31-story office building on the East Coast of the United States. On a typical day, the building houses a population of approximately 2100 people. The building has two stairs (North and South) that both exit on the 2nd floor onto the street level. The two stairs are 1.38 m (54.25 in) wide (1.26 m (49.75 in) between handrails) and the individual steps measure 0.18 m (7 in) rise and 0.27 m (10.75 in) tread depth.

The travel distances between floors vary throughout Building 8. From floors 31 to 4, there are 18 steps between floors (interrupted by a mid landing 9 steps between floors). Between floors 3 and 4, the stair configuration introduces a horizontal transfer corridor around the mechanical area, essentially adding an additional floor between floors 3 and 4. For that reason, the travel distances between floors 3 and 4 are larger in the North and South stairs. From floors 3 to 2, there are 27 steps (interrupted by two mid landings with 9 steps between each landing). Finally, there is a horizontal travel distance from the North stair to the exit of the building. Again, these travel distances have been calculated in the spreadsheet file for Building 8.

The evacuation drill observed by NIST took place in the fall months of 2008 during normal business hours (before lunch). The full-scale, simultaneous building evacuation was unannounced; meaning that the population was made aware of the evacuation drill only by the sound of the fire alarm. Additionally, the elevators were not available for the population to use during the drill. Only people with disabilities were able to use the elevators for evacuation, and only the freight elevator was available for their use. Overall, 1242 of building occupants participated in this evacuation drill (704 in the North Stair and 538 in the South stair).

On the day of the drill, NIST collected data from 30 different camera locations in the two stairs observed. In both stairs, NIST placed cameras every other floor, specifically on floors 30 to 14 (every other floor), 11, 9, 7, 5, 4, and 2. Cameras were placed on odd floors between floors 11 to 5 because the building did not have a 13th floor. Cameras were also placed on even floors at the base of the stair (floors 2 and 4) since the exit floor (Floor 2) must be equipped with a camera to obtain exit times for all participants. For Building 8, the times of the occupants entering the camera view is taken at the edge of the main landing (shown by the green line in the adjacent figure) and the times of the occupants leaving the camera view is taken at the edge of the main landing (shown by the red line in the figure).

Spreadsheet for Building 8, North Stair
Spreadsheet for Building 8, South Stair