On the optimal width of pedestrian corridors

This paper analyses a pedestrian corridor representative of airport terminal piers, elevated walkways, and sidewalks. A calculus based methodology is developed to determine the optimal width of these corridors that minimizes the cost to users and operators. It is shown that when walking speed is a linear function of pedestrian flow and the facility cost is a linear function of width, the optimal width of a particular corridor is proportional to the passenger flow and to the square root of the ratio of value of time to unit cost of construction. The flexibility of the method including its use in investigating the sensitivity of optimal design width to changes in construction and maintenance cost, the functional form of the cost, stochastic variation in pedestrian flow and value of user time are discussed. A closed form solution for the optimum facility width is obtained when flow is stochastic, the travel time function is linear, but the facility cost is non-linear with an economy of scale relative to width. When flow is purely random and stationary with a given mean, and the travel time, facility cost functions are linear, the width increases by 40% relative to the case of deterministic flow equal to the mean.