For guaranteeing employee health and safety in the workplace, employers are required to implement precautions, which ensure that workers are brought to safety immediately in the case of emergencies. Here, the design of escape routes and emergency exits is paramount. In Germany, their number, locations and dimensions are regulated by the Technical Rules for Workplaces ASR A2.3. Some of the requirements contained therein are derived from earlier guidelines. The Committee for Workplaces (ASTA) therefore is currently examining and revising ASR A2.3. As part of the revision, two independent microscopic simulation models are utilized to investigate the extent to which narrowing escape routes, stairways, and the timely staggering of evacuations influence evacuation time.
The study reports that a small narrowing on both sides of an escape route, which is at most 15 cm wide over a short length in horizontal routes has no significant influence on the escape time. Moreover, escape routes which include vertical elements (stairs) are influenced by the stairs only. That is, employee flow is reduced by the stairs alone and any narrowing of the escape route is negligible, provided its dimensions lie within permissible limits. It was also found that a delayed alarm has a positive effect on the evacuation of affected floors. Further investigation is required to define the necessary escape route width and to define it as a function of the number of persons per floor.
School buildings were also investigated to examine the influence of classroom door width on evacuation time. A school that is compliant with the regulations of the Model School Building Directive (MSchulbauR) was used. The simulations clearly show that changing the width of classroom doors between 0.90 m and 1.20 m has no significant influence on school evacuation times. Instead, the width of the stairs was shown to be the biggest factor for limiting evacuation capacity.
Finally, it was possible to prove that the jump contained in Table 1 of ASR A2.3 Point 5 Paragraph 3 from an escape route with of 1.00 m for up to 20 people to a width of 1.20 m for up to 200 people does not reflect the correlation between the number of people and the necessary escape route width already proven in experiments. We recommend mapping this correlation in ASR A2.3.
Please download the complete report "Expert report on the escape routes in workplaces - influence of path width, stairs, doors and restrictions on the evacuation" (in German).
A. Kneidl, R. Könnecke:
Fachgutachten zu Fluchtwegen in Arbeitsstätten - Einfluss von Wegbreite, Treppen, Türen und Einengungen auf die Entfluchtung.
2. edition. Dortmund: Bundesanstalt für Arbeitsschutz und Arbeitsmedizin 2020. pages 102, PDF file, DOI: 10.21934/baua:bericht20200116