Dynamic Sign Guidance Optimization for Crowd Evacuation considering Flow Equilibrium

Table 1

: Temperature and wildlife count in the three areas covered by the study.

Symbol	Definition
	The number of people in grid during time interval .
	The number of people in grid who choose to move to grid during time interval , where .
	The number of people in grid who choose to exit with passing through grid during time interval , where .
	The travel time for people in grid to pass through grid and eventually evacuate from exit during time interval , where (unit: s).
	The travel time for people in grid selecting route to exit during time interval (unit: s).
	The number of people in grid selecting route to exit during time interval .
	The estimated travel time for people in grid moving into grid during time interval , where (unit: s).
	The expected travel time for people in grid moving into grid with free flow velocity during time interval , where (unit: s).
	The minimum travel time for people in grid moving from grid to the queue tail at exit during time interval , where (unit: s).
	The minimum travel time for people in grid moving to the queue tail at exit by passing through grid during time interval , where .
	The minimum evacuation travel time of people selecting route during time interval .
	The minimum evacuation time of people in grid during time interval .
	The moving distance for people in grid moving to grid during time interval , where .
	The queue length of exit , which is predicted during time interval , for the people arrives at exit at the time interval , where .
	Binary variables and pedestrians in grid choose exit to evacuate by passing through grid during time interval ; if the pedestrians can arrive exit during time interval , we have , otherwise 0, where .
	The pedestrian density in grid during time interval (unit: persons per square meter).
	According to the literature [41], the maximum pedestrian density is set at 5.4 persons per square meter for safety.
	The maximum number of people who allowed to moving into grid during time interval , that is, the acceptance capacity of grid , where .
	The maximum number of people who can move from grid to grid during time interval , that is, the output capacity of grid to grid , where .
	The ration of people moving into grid who are from grid during time interval , where .
	The through capacity between grid and grid ; it set according to the literature [38], where and denotes the length of neighbour edge between grid and grid .
	The transmission capacity for people who move from grid to grid during time interval , where .
	The area of grid (unit: square meter).
	Binary variables, whether the dynamic sign guide in grid points to grid