Pedestrian diversity in design of facilities: Development of standard pedestrian equivalent (SPE) factors

Pedestrian traffic flow does not always consist of individuals with uniform characteristics. Disparity in walking speed as a result of ageing is becoming more evident in populations of developed countries such as Australia. Unlike vehicular traffic where diversity is tackled by using passenger car equivalent (PCE) factors, pedestrian traffic analysis has no similar concept. This paper introduces the standard pedestrian equivalent (SPE) factor to normalise mixed pedestrian flow. A micro-simulation approach was employed to generate flow relationships with and without older adults in the commuter flow. The walking speed distributions of older adults in Brisbane, Australia, were used as input, and commuter characteristics were derived from design-guide values in order to highlight the effect of increased proportions of older adults on design values. The findings showed that a shift in pedestrian level of service (LOS) was observed as a result of introducing older adults. Additionally, increasing the proportion of older adults yielded lower SPE factors, suggesting that the overall negative effect decreases as the proportion increases. SPE values were higher for narrow walkways than for wider walkways as a result of more blocking and less overtaking. The concept introduced can be adapted to develop factors for design and analysis of constrained walkways catering to older adults.