A greatmany factors, such as the evacuation length, evacuation time,
risk perception of the individual and individual psychology, can influence
individual behavioral decisions in the evacuation process, and
the impact of these factors changes with time. According to the experience-
driven mindset, in emergency egress, pedestrians are more likely
to choose a routewith the least evacuation time, yet since this often coincides
with (about) the shortest path, and since the shortest path is
much easier to be computed (it is static while the path of least movement
time changes dynamically). Pedestrians often walk the shortest
path if they do notwant to think a lot about their choice. However, pursuing
either the shortest evacuation length or the least evacuation time
solely can easily result in the “faster-is-slower” phenomenon [31] because
of incomplete information. The essence of the “faster is slower”
phenomenon is a lack of knowledge of complete information. One pedestrian
lacks a complete understanding of the crowded condition and
the required time for evacuation in the real time. As a result, s/he is unable
to make a systemoptimum decision. Accordingly, too many pedestrians
choose the same evacuation path based upon their incomplete
information, and the congestion occurs due to high pedestrian density
in certain areas. That is to say, apart from the length of evacuation
route and the time of evacuation process, the density of pedestrian flow
is another significant factor that influences the efficiency of the evacuation
process. The definition and calculation of those three major factors
are described in detail as follows:
(1) Length of evacuation route (L). This factor aims to record the
total length of an evacuation route from the start node to the end
node. Basically, an evacuation route may include several links between
nodes in the evacuation network (see Fig. 2), and thus, can be a combination
of some evacuation paths. Given the uncertainty and complexity
of evacuation paths taken into account, the value of a specific evacuation
route can be expressed by Eq. (5).