Many heavy truck cabs have a sleeper berth behind the driver’s seat. With the new FMCSA HOS regulations in place, which limit daily and weekly hours that commercial motor vehicle drivers can operate their vehicles, use of sleeper berths may have increased. Past research has suggested potential links between environmental stressors and driver health and performance. These environmental stressors include exposure to air pollution, vibration, and noise within the cab and sleeper berth while driving and at rest stops. The objective of this research study is to improve heavy truck ergonomics in order to reduce fatigue and improve driver health and performance. It will simultaneously measure air pollution concentrations, noise, and vibration inside heavy-duty diesel truck cabs and sleeping berths while driving in different speeds and idling at a truck stop.