Large trucks, commonly referred to as “big rigs,” “semi-trucks” or “tractor trailer” trucks typically weigh 80,000 pounds and range from approximately 67 to 75 feet in length. Despite that large trucks represent only 3% of all registered vehicles on the road, they account for over 25% of passenger vehicle occupant deaths in multiple vehicle accidents.
The tremendous difference in size and weight between passenger vehicles and large trucks make visualization of catastrophic injury easy. However, the difference in size and weight between passenger vehicles and large trucks are at issue. For example, it will take a 40 ton 18-wheeler driving at 65 miles an hour an additional 100 feet to stop than were it traveling at 55 miles an hour. Given this, it is not surprising that typical big rig accidents usually involve rear-end collisions. Jack-knifed trailers, right hand squeeze, and brake failure are also common accidents involving large trucks.
The Role of Bio-Mechanical Evidence and Recreation in Injury Trials
In the past 50 years, thousands of motorists and truck drivers have been killed and/or injured in large trucking accidents primarily resulting from driver error and negligent maintenance by trucking companies. Unsafe driving, over-sized loads and other acts of negligence have put the public, as well as, truck operators in danger.
California is one of approximately 10 states which impose a slower speed limit for large trucks and commercial vehicles. Approximately 7% of all of the vehicle miles driven in the nation are done so by large truck drivers. Federal crash statistics have shown that at least 20% of large trucking accidents are due to excessive speed. This is especially so when coupled with problems resulting from excessive speed and braking.
Nonetheless, while mechanical failures, reckless driving and improper driver training account for many of the crashes, the National Highway Transportation Safety Association (NHTSA) reports that driver fatigue is responsible for between 30% and 40% of all big rig crashes and is the probable cause in over 30% of the crashes that resulted in the truck driver’s death.
Much like the tragic frequency of traumatic brain injury in this country, every 16 minutes, each day, another person in the United States will be injured or killed in a trucking-related accident. It is not surprising that at least one-third of the injured suffer catastrophic harm and damage. In 2003 alone, over 450,000 large trucks were involved in crashes. In a survey done that year, almost 20% of truckers admitted to falling asleep at the wheel at least once in the previous three-month period.
However, each year about 600 large truck occupants are killed and about 30,000 are injured in highway crashes according to data collected by NHTSA. (This compares to approximately 5000 deaths resulting to passengers in smaller vehicles involved with large trucks and over 140,000 injuries per year to individuals operating smaller vehicles involved with large truck accidents).
Clearly, in multiple vehicle crashes, smaller vehicles and their occupants are at a vast disadvantage when a large truck is involved. Nonetheless, large truck safety should involve safety to big rig drivers and their occupants as well as safety to smaller vehicles.
In 2004 alone, an estimated 200,000 new trucks had been registered to operate on United States roads. One would hope that the registration of “newer” vehicles would result in safer trucks. This is not necessarily the case however. In many instances, the cabs of large trucks are designed to do little more than keep out wind and rain. Relatively minor crashes, especially those not involving other vehicles, can and do often result in catastrophic injuries to truck operators and passengers. There is a dearth of federal regulation or efforts by truck manufacturers or trucker trade unions to provide rudimentary safety measures to protect truck drivers. Doors should stay shut, windshields should not pop out, and some type of safety cage, ought to be, but isn’t normally available.
Newly registered trucks and ever expanding fleets of trucks results in greater competition. Drivers are under increased pressure to deliver faster in order to remain competitive. While regulations state that a big-rig operator can only “drive” for 10 hours per day, and must have 8 hours off for each 10 hours of driving, there is also load/unload time, often involving hours of physical labor. It is no wonder that truckers admit to falling asleep at the wheel. Many times the truckers’ 10 hours of driving begins after hours of physical labor getting the load ready to go.
Unfortunately, when a 2000 pound automobile is involved in an accident with an 80,000 pound tractor-trailer, even the best of passenger vehicle design may not prevent catastrophic injury from resulting.
The Scarlett Law Group has been involved in big rig accidents resulting from improper maintenance, braking problems, driver error, jack-knife, lane change error/blind spot, as well as fatigue. Despite that the resulting harm to passenger vehicles and occupants is easily seen, the Scarlett Law Group routinely utilizes the services of biomechanical engineers and accident reconstructionists, as well as safety specialists, mechanics and others in order to convincingly establish their clients’ cases.
Given the dramatic proportional difference between passenger vehicle and big-rig, accidents involving alleged operator error, or mechanical error in semi-tractor-trailers, generally these are vigorously defended. It is not uncommon for the defense to point to driver error on the part of the passenger vehicle operator. Did he or she cut in front of the truck? Did he or she operate their passenger vehicle in a blind spot for an inordinate amount of time? Was an improper passing technique utilized by the passenger vehicle?
While liability for many vehicular/trucking collisions is clear, accident reconstruction and workup of the biomechanics of injury are nonetheless required for proper trial presentation in virtually all such cases. The Scarlett Law Group works with top experts on this subject.
For example, many are surprised to learn that most SUVs and pickup trucks maintain a rigid bumper system which clearly can result in much greater injury to occupants in even low speed impact collisions.
The presence or absence of motor vehicle bumper damage is usually thought to be an important consideration when estimating the severity of a low speed, or minimal damage collision. There are, however, several types of bumpers. Most passenger car bumpers contain elements designed to dissipate the impact energy, such as shock absorber-like isolators, foam cores or lattice cores. A number of studies have provided insight into analyzing collisions involving these kinds of bumpers.
A rigid bumper system, such as contained on most SUV and pickup trucks, typically consist of a steel bumper beam attached to the vehicle frame either directly or by mounting brackets. Rigid bumpers are common on pickup trucks, vans, and sport utility vehicles.
In one study, full-scale impact testing was selected as a method of investigating the performance of rigid bumper systems during low-speed collisions. A vehicle-to-vehicle test is clearly the best facsimile of the actual collision. However, barrier impacts are widely used in mandatory standards compliance tests, and the relative ease of conducting a barrier test makes it an attractive alternative to a vehicle-to-vehicle test when assessing the behavior of a rigid bumper.
In at least one study, comparison was made between the damage produced in barrier and vehicle-to-vehicle tests of a similar severity to assess the viability of barrier testing when analyzing real-world collisions involving rigid bumpers. The Scarlett Law Group, together with its experts, maintains constant review of all literature in this area, and when re-enactment, via computerized projection or actual vehicle reenactment is performed for forensic purposes, the Scarlett Law Group and their experts chooses the most viable option available.
For example, in one study 5 pickup trucks were subjected to barrier impacts and vehicle-to-vehicle impacts on both their front and rear bumpers. Prior to each test, replacement bumpers and mounting hardware were installed by a local auto body shop.
The vehicles tested included a 1980 Ford F-150 Pickup, a 1981 GMC C-1500 Pickup, a 1983 Toyota Half-Ton Pickup, a 1983 Chevrolet S-10 Pickup, a 1984 Ford Ranger, and a 1993 Ford Crown Victoria. Original manufactured equipment and parts were used for all of the vehicles.
- Speed, damage, and high-speed video were recorded for each test. Impact force was recorded for the barrier test.
- A MacInnis Engineering Associates “fifth wheel” was attached to each test vehicle to measure speed during the collisions. Collected at 256Hz, this device provides speed resolution of about 0.04km/h.
- The barrier was equipped with two uni-axial lode cells to measure impact force. This data was collected at 256Hz.
- All test vehicles were weighted axle-by-axle using an 11kN load cell with a resolution of 10N.
Video of the bumper’s impacts was recorded using an omniSpeed HS motion capture system and high speed digital cameras. Video data were recorded at 250 frames per second, using a shutter speed of 1/1000.
First, the front and rear barrier impacts were conducted with all vehicles, followed by front and rear impacts with the rear and front bumpers, respectively, of the 1993 Ford Crown Victoria 4-door sedan.
The test vehicles were pulled into impact by a speed controlled electronic winch and a steel cable attached to the undercarriage. Just prior to impact, the winch was turned off, so the vehicle coasted into contact.
The barrier consisted of a horizontal steel beam with a rectangular cross-section attached by two lode cells to a rigid frame. The frame was bolted to a concrete floor. The height of the impact beam was adjusted so that the center of the beam was approximately level with mid-height of the bumper.
A 1993 Ford Crown Victoria was used for vehicle-to-vehicle collision with the pickup trucks. In each of the rear bumper tests, a stationary pickup truck was struck by the front of the Crown Victoria. The Crown Victoria was towed to the required speed by the electric winch, and released just before impact. For each front bumper test, the pickup truck was towed into the rear of the stationary Crown Victoria in a similar manner.
The striking vehicle impact speed for each vehicle-to-vehicle test was selected so that the speed change experienced by the pickup truck would nearly match the speed change observed in the corresponding barrier test. Coefficients of resolution were predicted using approved methodology.
The striking and target vehicle bumper heights matched in all tests.
The differences between the damage caused in the vehicle and barrier tests was found to be generally attributable to the difference in the shape of the barrier and the Crown Victoria’s bumpers. The Crown Victoria’s bumpers were curved and these curvatures resulted in non-uniform loading of the bumper beam and the mounting brackets. In many of the tests the horizontal curvature caused greater deformation between the bumper mounts than the barrier test.
The bumper damage was similar in the vehicle and barrier tests if the bumper mounts buckled. The exception was the Toyota rear bumper, which rotated in opposite directions in both vehicle and barrier tests, though with about equal magnitude. However, if the bumper mounts did not fail, or if the bumper was mounted directly to the frame rails, then bumper damage was different in the vehicle and barrier tests. In these cases, the bumper beams tended to bow between the unyielding mounts and when contacted by the rounded vehicle bumper, they remained flat after the barrier impact.
If you or someone you know has been injured as the result of a trucking accident, you need the assistance of The Scarlett Law Group. Call (415) 688-2176 today to speak with a California Personal Injury Attorney.
The test data presented in this study established that both front and rear bumpers of five pickup trucks sustained at least localized damage when subjected to nominal 8km/h speed changes in collisions with a fixed barrier or another vehicle. Full-sized pickup trucks sustained less bumper damage than compact trucks for equivalent speed changes, though there was variation in compact truck performance. Nonetheless, given the rigid nature of the bumper itself, little damage to the bumper did not equate to the forces subject to the occupants of the vehicles itself. In fact, through utilization of appropriate biomechanical testing, it was determined that the absence of bumper damage on a rigidly mounted bumper did not in any way rule out the probability of serious injury, including brain injury, to the occupants therein.
Accordingly, by utilizing appropriate experts, and by staying abreast of current literature, the Scarlett Law Group is able to educate juries as to why serious injuries occur with seemingly little property damage.
Even in cases involving significant property damage, for example, where the Jaws of Life has been utilized in order to extricate the occupants of a vehicle, biomechanical analysis must still occur. Whether the collision involves a large truck, a school bus, a pickup truck, or a small sedan, the Scarlett Law Group, and its team of experts, stand ready to assist you in your time of need.
In any large truck/passenger car accident, even though you, or your loved ones, have been seriously injured, do not expect that your conduct will not be scrutinized by the defense. By reconstructing the accident, and by employing appropriate bio-mechanical specialists, the Scarlett Law Group eliminates and eradicates misplaced defense arguments. If you, or a loved one, have been in an accident involving a tractor trailer or a large truck, the Scarlett Law Group has the expertise to assist you through your difficult times.