Ernst Bosina

Defining the time component of the pedestrian LOS concept

1 For pedestrians, a number of density-based Level of Service (LOS) schemes exist in the 2 literature. Although their values differ substantially, several common principles can be identified 3 as necessary assumptions of this LOS concept. From these assumptions follows the importance 4 of the time aspect of the LOS. Pedestrian flows are typically characterized by strong, often short5 term, fluctuations. The LOS thus depends strongly on the chosen measurement interval. This link 6 is highly relevant when designing infrastructures, as time-aggregated pedestrian counting data 7 are often used in practice. Despite this fact, the time-dependency of LOS is hardly discussed in 8 the literature. 9 This paper attempts to provide a conceptual basis for the pedestrian LOS based on a 10 comprehensive review of the literature. With the increasing availability of continuous counting 11 data, the time component of the pedestrian LOS concept can be examined in more detail. A case 12 study described in this paper, together with a recently published LOS concept, illustrates the 13 influence of flow variations on the LOS and the perceived quality of the flow. Results show that 14 the time interval can be incorporated into an LOS scheme in a meaningful way, although certain 15 limitations remain. It is furthermore argued that facility design should be based on ensuring a 16 certain minimum LOS for a defined share of users, provided that detailed continuous counting 17 data is available. Such an approach would best enable the construction of cost efficient as well as 18 comfortable pedestrian facilities. 19 20 21

Avoiding walls: what distance do pedestrians keep from walls and obstacles?

To avoid colliding with walls and obstacles, pedestrians keep a certain distance to them. This so-called separation distance or wall clearance distance was documented in early literature on pedestrian transport. For modelling purposes, it can be subtracted from a walkway’s width to obtain an effective width. Literature on this topic is scarce and the values that can be found are often contradictory, largely due to a lack of data. This work aims at contributing to the knowledge about the pedestrian wall distance by applying several high-resolution measurement techniques. Measurements were carried out using ultrasonic transducers and laser scanners at locations where high numbers of pedestrians move in a unidirectional flow. The results confirm that pedestrians keep a minimum distance to walls and that the effect of obstacles is noticeable several metres downstream of the cross section in which they occur. Furthermore, it was found that the kept distance depends on the pedestrian density. Lastly, this paper suggests a method for determining the effective width of walkways that can be used in pedestrian facility design.