On-Board Comfort of Different Age Passengers and Bus-Lane Characteristics

Onboard bus comfort significantly depends on the bus lanes characteristics, such as horizontal curvature, pavement roughness, longitudinal, and transversal slope. A literature review shows a statistical relationship between acceleration level and passenger features, such as age and gender. A large number of onboard interviews have been collected and correlated to bus-lane geometry parameters, to evaluate the vibrational comfort of different passengers. Passenger's judgments are related to the lateral, longitudinal, and vertical shake. At the same time, a geometric investigation on bus-lane corridors, traveled during interviews, in the city of Cagliari in Italy allowed to extract infrastructure parameters in terms of numbers and density of turns, horizontal curvature radius, speed design, and acceleration variance. The paper analyzed the correlation between some geometric and cinematics road parameters that may affect the comfort and the different passenger's judgments on the three acceleration components by age classes and hourly day. The results generally show weak correlations between the selected parameters and passenger judgments. Conversely, travel speeds have significant correlation values. There is a moderate inverse correlation between the vibrational level and the age of the passengers. The younger age groups tend to have more severe judgments, attributable to their higher demand for comfort. The presence of preferential lanes increases the onboard comfort quality in terms of speed regularity, without private cars interferences.