NHTSA Complaint #11509676 — 2020 FREIGHTLINER CASCADIA

In this truck, and in other CMVs with down-facing exhaust, and with complete aerodynamic panels, exhaust gases are trapped under the body, and are circulated into the cab. Much worse when parked, but noticeable when driving. I can smell regen soot in the cab when moving at highway speed, meaning that exhaust is getting from the exhaust pipe to the cab interior. This vehicle VIN has this problem, but i have found it to be present in most other newer models of CMV, to varying degrees. The style of exhaust that ends above the roofline (vertical stacks) do not present this problem. This particular vehicle has no auxiliary power unit, so when idling is necessary, enough exhaust makes it in the cab to cause coughing. The down facing exhaust design, coupled with aerodynamic panels that trap and funnel exhaust gases to the interior of the cab, are a critical design flaw. CMV drivers are constantly breathing varying levels of exhaust gases, even when driving. I have thermal videos of exhaust, from a parked truck, moving from the tailpipe forward to under the hood. Every gas under the hood and sleeper body ends up in the cab and sleeper. As a test, fluorescent leak detecting liquid could be aerosolized into the exhaust stream near the end of the tailpipe, or outside the tailpipe near the exhaust pipe opening. After idlng for a while, and after driving with the leak detection liquid being sprayed, a black light could be used to show everywhere the gases go. Drivers cannot idle the trucks nor drive down the road without being firced to breathe exhaust for up to 20+ hours a day. These gases, including the burnt regen gases/soot, are bad for the worker's health, and can impair cognitive function. Also, this is a clear violation of DOT and EPA safety rules for CMVs. Since the DOT rules state that exhaust cannot be expelled under the hood or cab/sleeper, the exhaust is designed to come out a few inches behind the sleeper. The exhaust still comes into the cab.