Factors are suspected to influence health and performance of drivers—noise level, seat vibration, and cabin air quality of heavy-duty diesel trucks—were measured while vehicles were parked with engine idling and driven. Resulting data will serve as baseline data from which future similar studies may determine if new truck designs have changed the existing state of these conditions for long-haul freight truck drivers. Twenty-seven trucks (model years 2006–2008) from four manufacturers were tested. Overall in-cab noise levels were found to be below 8-hour standard limit values. Results indicated slightly higher noise levels occurred while driving on interstates compared to driving on the State highways. Average vibrations from the seats were generally found to be below standard exposures for an 8-hour driving day. Air quality was determined by measuring in-cab concentrations of carbon monoxide (CO), nitrogen oxides (NOX), and particulate matter less than 2.5 microns aerodynamic diameter (PM2.5). Results indicated trucks have a tendency to self-pollute the cabs during periods of extended parked engine idling; the on-road concentrations were several magnitudes lower. CO and NOX concentrations were well below standard permissible exposure levels. However during several parked-idling scenarios, PM2.5 concentrations were slightly higher than ambient air quality standards. (Author/publisher)
Abstract