Human Factors Engineering

A new publication in TR part F by Semyon Kalantarov, Raziel Riemer, and Tal Oron-Gilad.

Highlights:

• Road-crossing simulator synched with a 3D motion capturing system was built
• Time pressure and longer wait times cause riskier crossing decisions
• Pedestrians adjusted posture, crossing speed and timing of crossing to the risk taken
• Body parts’ movement prior to the crossing can be divided into four increments

In this study we examined pedestrians’ crossing decision, body parts’ movement and full body movement, just before and during road crossing in a simulated setup. To accomplish this, a novel experimental setup for analyzing pedestrians’ crossing behavior and motion was developed where the simulated display was synchronized with a 3D motion capturing system. Twenty participants, divided into control and an experimental time pressure group, observed sixteen short (less than 30 seconds) and long road (70 seconds or more) crossing scenarios with varying crossing opportunities. Based on the crossing opportunities they were asked to cross a 3.6 m wide one-lane one way urban road. It was found that the crossing initiation process consists of four incremental movements of body parts: the head and the shoulder first; the hip, wrist and elbow second; the knee as a separate joint, and finally the ankle. Results showed that pedestrians’ decision to cross and body parts movement are influenced by time pressure and wait time for a safe crossing opportunity. Specifically, pedestrians prepare their body parts earlier, initiate their crossing earlier, and adjust their speed to compensate for the risk taken in less safe or non-safe crossing opportunities. Within the control group, women tended to be more risk avoiding than men, however those differences disappeared in the time pressure group. Most importantly, the findings provide initial evidence that this novel simulation configuration can be used to gain precise knowledge of pedestrians’ decision-making and movement processes.

What did we learn about pedestrians crossing movement?
Pedestrians change their strategy as a function of internal and external reasons:

• Take higher risk when crossing opportunities are sparse or when they are under time pressure

Initiate crossing, Kalantarov, Riemer, and Oron-Gilad for TRF

• Prepare their movement in advance by adjusting body position

body parts movement, Kalantarov, Riemer, and Oron-Gilad for TRF

• Change the timing of crossing as a function of perceived risk

timing of crossing, Kalantarov, Riemer, and Oron-Gilad for TRF

• Adjust their crossing speed to the perceived risk

walking speed, Kalantarov, Riemer, and Oron-Gilad for TRF

Kalantarov_, S. , Riemer, R., Oron-Gilad, T. (in press). Pedestrians’ road crossing decisions and body parts’ movements. Transportation Research Part F: Psychology and Behaviour.