A Study of Riders' Noise Exposure on Bay Area Rapid Transit Trains

Abstract

Excessive noise exposure may present a hazard to hearing, cardiovascular, and psychosomatic health. Mass transit systems, such as the Bay Area Rapid Transit (BART) system, are potential sources of excessive noise. The purpose of this study was to characterize transit noise and riders' exposure to noise on the BART system using three dosimetry metrics. We made 268 dosimetry measurements on a convenience sample of 51 line segments. Dosimetry measures were modeled using linear and nonlinear multiple regression as functions of average velocity, tunnel enclosure, flooring, and wet weather conditions and presented visually on a map of the BART system. This study provides evidence of levels of hazardous levels of noise exposure in all three dosimetry metrics. L eq and L max measures indicate exposures well above ranges associated with increased cardiovascular and psychosomatic health risks in the published literature. L peak indicate acute exposures hazardous to adult hearing on about 1% of line segment rides and acute exposures hazardous to child hearing on about 2% of such rides. The noise to which passengers are exposed may be due to trainspecific conditions (velocity and flooring), but also to rail conditions (velocity and tunnels). These findings may point at possible remediation (revised speed limits on longer segments and those segments enclosed by tunnels). The findings also suggest that specific rail segments could be improved for noise.

Metrics in Urban Health: Current Developments and Future Prospects

“…With respect to noise pollution, half of the studies focused on determining the impact of road traffic noise on health (23,26,51). However, results varied and were sometimes inconclusive on the actual impact of traffic noise pollution (26).…”

Noise Levels Associated with Urban Land Use

“…9 Exposure to environmental noise from traffic-related sources is reportedly the most annoying of all urban pollution types, 10 interfering with enjoyment of daily activities and largely affecting sleep and rest patterns. [10][11][12] In a recent Canadian survey, 20-28 % of urban populations attributed noise from road traffic to disruptions during sleep, conversation, and communication tasks such as reading and writing.…”

“…9 Exposure to environmental noise from traffic-related sources is reportedly the most annoying of all urban pollution types, 10 interfering with enjoyment of daily activities and largely affecting sleep and rest patterns. [10][11][12] In a recent Canadian survey, 20-28 % of urban populations attributed noise from road traffic to disruptions during sleep, conversation, and communication tasks such as reading and writing. 13 Few studies have conducted field measurements to assess levels of environmental noise in Canadian cities; furthermore, it is still unknown whether recent trends towards the intensification of urban development will impact environmental noise levels and in turn population health.…”

Mass Transit Ridership and Self-Reported Hearing Health in an Urban Population

“…Data from recent studies suggest that transit users are potentially exposed to noise that is in excess of recommended community limits (i.e., 70 dBA/24-h period), 8,9 especially for those riders with extensive commute times. 10,11 Hazardous levels may be of particular concern in some urban centers with older transit systems, as these have generally not benefitted from newer sound-dampening design features or engineering controls. In the US, there are five subways systems that are more than 75 years old, and four (Boston, Chicago, NYC, and Philadelphia) are more than 100 years old.…”

“…Excessively loud noise has also been documented on newer systems, such as the regional Bay Area Rapid Transit (BART), which operate at much higher speeds than older systems. 10 Subways are not the only mass transit source of excessive levels of noise. Hazardous levels have been reported for all forms of mass transit in NYC.…”