2024 Freightliner Cascadia

The cruise control has been programmed to stay engaged, in many instances, after the driver has used the foot brake. In some situations, like approaching a traffic circle, I have slowed down with the foot brake, then had the truck unexpectedly start to accelerate after I released the brake. This apparently has to do with a vehicle in my headway allowing the cruise to remain engaged, and then after the vehicle leaves my headway the truck thinks it can accelerate again. There is never a good reason for the cruise control in any vehicle to remain engaged after using the brakes. This results in unpredicted situations, like unplanned acceleration. This also applies to vehicles trying to merge in front of me, where I use the brakes to back off some and allow them in, but then the cruise (still engaged) will accelerate again toward the vehicle that was previously in my headway.

Complaint 1 When using cruise control in 2024 Freightliner Cascadia trucks with level 2 autonomous driving features, there is no option to turn off the autonomous driving features (and use standard cruise control); the driver is forced to use the system if he wants or needs to use cruise control. This apparently is a software setting that is available in some versions, but is not available in models bought/leased to large trucking companies. Complaint 2 There is no way to adjust the "agressiveness" of the self-driving (acceleration and braking) feature of these trucks. The default in this model truck is unknown to me, but in slow-and-go or stop-and-go traffic, the truck is highly aggressive; the truck follows too close very often, and waits until the last second to slow or stop in most cases. This also happens in high volume, higher speed traffic.

These trucks have a non-adjustable default setting for Over and Under cruise control speed setting. This means, in the case of the truck I drove, that the cruise control will allow the truck to go 5 mph over the set speed before engaging the engine brake, or 4 mph under the setting before accelerating. The problem is that when set for the speed limit, the truck will climb to 7 mph over the set speed before engaging engine brake. When driving on a downgrade with a lot of weight, the truck quickly gets to well over a safe speed before the truck will attempt to slow down. This often results in an overspeed situation when approaching curves. In older models of Freightliner, and maybe in current versions that are adjustable, there is a setting to change this to closer to the set speed. In this model, or large companies' ordered versions, this adjustment is not available. The idea is to save fuel by "hyper-mile" style of driving. It makes for an unpredictable speed of vehicle, frustrating other drivers, and sometimes leading to unsafe overspeed situations.

When a vehicle is merging into my lane, the truck will often not detect or react to the encroaching vehicle; this happens even when there is plenty of space, and the encroaching vehicle is halfway into my lane. I have had to intervene several times, since the truck was accelerating toward the previous vehicle in my headway, and ingoring the intervening merging vehicle. In contrast, the sensors in the truck apparently can see when a vehicle is near to the front, and mostly out of the headway of the truck (only part of the front vehicle in my lane, like when exiting). This truck will brake, and continue braking unnecessarily (and unnecessarily hard braking) for a vehicle that is completely out of my lane (by several feet), before continuing and regaining speed. This shows that the sensors are capable of "seeing" and tracking the vechicles, but still does not respond to traffic merging into the truck's headway.

When driving in highway traffic at moderate to high speeds (as well as low speeds), the truck will often accelerate with (and towards) a vehicle that is less than 1 second ahead of the truck. Certainly this often happens when there is not a safe distance between the truck and the next vehicle. The trucks systems in no way seem to expect that the next vehicle could slam on brakes at any moment. I have had this happen many times when a vehicle merges too close in front of me and then accelerates. The truck will accelerate with the vehicle (that the truck is now tailgating), even though there is slowing or stopping traffic directly ahead of the vehicle the truck is following. The Safety Director at Tyson Foods, Robert Carl, told me in a conference call about the unsafe flaws in the truck, that these Freightliner systems are programmed to "try" to maintain about a 2.5 second following distance. Even this is patently unsafe. Driver safety guidelines (FMCSA) are: "If you are driving below 40 mph, you should leave at least one second for every 10 feet of vehicle length. For a typical tractor-trailer, this results in 4 seconds between you and the leading vehicle. For speeds over 40 mph, you should leave one additional second." It would appear that Daimler/Freightliner may have used Autonomous Driving software that was designed for cars, and has tried to "adjust" it to work in tractor-trailers. That is speculation, but based on the supposed target following distance, that may be correct. 2.5 seconds is certainly too close, and the distances of less than 1 second that I have commonly seen are not acceptable in any truck.

The cruise control (level 2 autonomous) will turn itself off without any warning sometimes. This happens any time the truck is set for above the speed limit by more than 2 mph. The truck uses a speed limit map, independent of actual posted speed limits. When the truck detects a speed limit drop to below the cruise setting, either real or imagined, the cruise control disengages without any warning or notification. This is a problem when I expect the truck to continue its autonomous function in traffic situations, but it does not, and without warning. The system will even disengage while it is operating; it will be slowing or maintaining a following distance, then disengage. The driver has no idea if the truck is still auto-driving until he is close to a rear-end accident. Also, bear in mind that speed limit signs are often only posted on the right side of the road; If there is something blocking the sign, like another vehicle, the cruise will still disengage without warning, and the driver does not know it. The only way to tell if cruise is still engaged is by looking for a small green icon in the bottom left of the dash display, which is over 20 degrees down from focal view. Also, there are times when the cruise disengages for no apparent reason. Sometimes there is a barely audible bluetooth-disconnect type sound, but often there is no audible warning. There is also no display warning of any type.