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Jeffrey Ball, Ph.D., P.E. Dr. Jeff Ball specialized in mechanical engineering design , motor vehicle accident reconstruction , and patent infringement evaluation. After graduating from the United States Air Force Academy as a pilot, Dr. Ball continued his educational journey and attained his M.S. in Engineering from Purdue University and a Ph.D. in Engineering Science from Oxford University. Soon after, he returned to his alma mater as both a flight instructor and a Professor of Mechanical Engineering. He taught courses on machine design, product design, automotive engineering, thermodynamics, statics, strength of materials , and dynamics. As a pilot, Dr. Ball flew supersonic fighters and gliders and later instructed young cadets. During his time with the United States Air Force, Dr. Ball also supervised Air Force cadets in the design, testing, and operation of race cars for the Society of Automotive Engineers’ (SAE) Formula Competition and the SAE Mini Baja Competition. He also conducted research, modeling, and testing on internal combustion engine performance and directed a research project for the USAF on alternative powerplants for unmanned aerial vehicles. Finally, as a graduate of the USAF Accident Board President Course, he was certified to conduct aviation accident investigation for the Air Force. ​ Jeff passed away on July 12, 2020. He will be missed but not forgotten. ​ ​ ​ ​

Pedestrian and Bicycle Accident Reconstruction Commuter, Bicycle, Skating, and Electric Scooter Crash Analysis Pedestrian and bicycle accident reconstruction requires a very specialized skill set in order to accurately reconstruct the incident. Often times, there is very little physical evidence as a result of the crash, or the physical evidence is not properly documented by emergency personnel. Under these circumstances, the keen eye and experience of a well-qualified accident reconstructionist is crucial to understand what happened, and why. Veritech’s forensic engineers are experienced with reconstructing all types of vehicle accidents involving pedestrians, bicyclists, skateboarders and in-line skaters. ​ ​ Pedestrian Accidents Veritech engineers are experienced with reconstructing all types of pedestrian versus vehicle accidents, including those involving automobiles , semi tractor-trailers , trains , and even construction equipment . These types of accidents can be very serious or even fatal, and therefore require special attention when performing a reconstruction. For example, one of the most significant reconstruction issues is related to the substantial weight difference between a pedestrian and a vehicle. Due to the large difference in weight, it can be difficult to determine the speed of a vehicle at impact with a pedestrian using standard accident reconstruction techniques. ​ ​ Because of this, methods that are unique to pedestrian accidents have been developed. These methods take into consideration the geometry of the impacting vehicle’s front end, the location of the vehicle’s point of contact on the pedestrian’s body, and even consider whether or not the pedestrian became airborne as a result of the impact. Pre-impact visibility and environmental factors also play a significant role in these accidents, and therefore should be accounted for appropriately. ​ ​ Skateboards, Longboards, and Inline skates Veritech’s forensic engineers have experience in reconstructing collisions where pedestrians are riding on skateboards, longboards, in-line skates, and other wheeled sports equipment. The performance characteristics of a skateboarder or roller-blader involve much faster traveling speeds (and likely subsequent impact speeds) compared to a walking pedestrian. Additionally, the acceleration and braking rates for a pedestrian on a skateboard are also much different than a walking or running pedestrian. Also, the height of a pedestrian’s center of gravity changes when riding, and furthermore, the center of gravity can change depending on the posture of the pedestrian while riding. ​ ​ Even the action of riding and propelling forward will result in a dynamic position of the pedestrian’s center of mass, producing a different accident situation than a simple walking subject. Veritech has performed real-world tests on a number of subjects while riding skateboards and longboards. From these tests, performance characteristics unique to skateboards have been developed for the sole purpose of aiding in forensic engineering and accident reconstruction. ​ ​ Bicycle and Electric Scooter Accident Reconstruction Perhaps the most common type of mechanized transportation for commuters, aside from automobiles, could be riding bicycles. Bicycles provide a user the ability to achieve significantly faster speeds than walking. What’s more, riding bicycles is a favorite recreational activity of many individuals. When things go wrong, bicyclists crash, sometimes individually from a loss of control and other times from contact with another rider or automobile. Bicycle accidents can be very serious, largely due to the increased speeds involved but also due to the loss of stability during a crash. While many on-road accidents consist of impacts with automobiles or stationary objects, off-road accidents can be just as severe, resulting in injuries from contact with rough, rocky surfaces. ​ A relatively new mode of transportation involves the use of electric bicycles (also known as “E-bikes”) and electric scooters for commuting and recreation. These two-wheeled vehicles are powered by a small electric motor with an onboard battery and have the capability of reaching 20 mph or faster. Many metropolitan areas are equipped with fleets of electric scooters and bicycles that are available for rent and can be used by virtually anyone. Rental companies such as Lime and Bird offer fleets of electric scooters and bicycles in many major cities across the country. These units are very popular and provide a quick and easy way for pedestrians to commute through congested city streets. Unfortunately, due to the relative ease in acquiring one of these rental units, many riders operate them without the use of a helmet or other safety equipment. Their usage on busy city streets around walking commuters and automobiles results in frequent accidents, and when an electric scooter or E-bike operator crashes without a helmet for head protection, injuries can be serious. Veritech has experience in reconstructing all types of bicycle, e-bike, and electric scooter accidents occurring on both on and off-road surfaces, and has developed their expertise due in part to their level of riding proficiency and extensive training in rider dynamics. Please contact one of our licensed professional engineers at 303-660-4395 to discuss your case and receive a free initial consultation with honest and candid comments. Mark Kittel, P.E., D.F.E. Principal Engineer Joe Tremblay, P.E., D.F.E. Senior Engineer

Previously, we discussed the differences in stopping distance between passenger cars and semi tractor trailers. In this previous post, we discussed that there are some fundamental differences between the two types of vehicles and generally speaking, heavy semi tractor trailers take longer to stop than passenger vehicles. It’s interesting to note that stopping distance is influenced greatly by the tire compound for the stopping vehicle. This is universally true, as tire compound affects the friction available between a tire and the roadway surface. Today’s post will discuss stopping distance of another popular vehicle type: motorcycles. Motorcycles are capable of stopping very quickly. How do they compare with passenger cars? Read on to find out: Scenario: to lay out the difference, consider the following scenario comparing passenger cars, semi tractor trailers, and motorcycles: a full braking stop from 60 mph takes a: Motorcycle: 110 feet Passenger Car: 170 feet Semi Tractor Trailer: 215 feet The numbers are drastically different. It is amazing to think that a motorcycle would be stopped in almost half the distance that it would take for a semi tractor trailer to stop. Tire construction: Stopping distance is related to tire compound. Softer compound tires allow for better grip but wear out faster. For example, motorcycle tires in general are designed to only last thousands of miles, instead of tens of thousands for car tires, or hundreds of thousands of miles for semi tires. Better grip is also more important for a motorcycle than it is for four-wheeled vehicles because loss of grip can often mean a crash for a motorcycle, whereas only a loss of control for a car or truck. Rider Skill Level: Another issue that comes into play with motorcycles is rider skill level. The ability for a rider to properly apply brakes for the most effective stop possible requires that the rider know how to apply both front and rear brakes to their fullest extent, and most importantly, not crash during brake application. Learning how to properly apply brakes takes some practice, and a novice rider will likely not be able to stop as quickly as a veteran rider would. This is an interesting variable that is often overlooked by reconstructionists who claim to have experience in motorcycle accidents. Automobiles, trucks, and semis all provide the driver with maximum braking capabilities, regardless of the skill level of the driver. However, rider skill level has a direct impact in stopping distance for a motorcycle. Therefore, it is important to consider motorcycle rider skill level when discussing the topic of stopping distance. Anti-Lock braking: Even motorcycles can benefit from ABS technology. With the advent of anti-lock braking, automobiles suddenly were given the ability to stop and maintain control at the same time. Motorcycles can also take advantage of ABS systems, and the majority of motorcycle manufacturers these days offer ABS on their bikes. ABS systems on motorcycles have the ability to help the rider apply maximum brakes without the risk of losing control through a low-side or high-side event during braking. Veritech’s engineers are avid motorcyclists and have the skill and experience to reconstruct your accident correctly. Call us today with your case!

At Veritech, we perform a lot of accident reconstructions that start with black box data downloads from vehicles. We’ve covered black box downloads in other blog posts. These downloads capture pre-impact, impact, and post-impact data that are related to a crash. The information gathered during a download can be valuable as a starting point when performing an accident reconstruction. After all, having information relating to the vehicle’s speed and pre-impact behavior is often important when coming up with answers relating to a car accident. Most commonly, the vehicle’s airbag control module or “ACM” is the electronic piece of equipment that does the data logging during an accident. The ACM is what decides on deployment of the vehicle’s supplemental restraint system, or airbags. In some accident scenarios, the ACM may determine that airbag deployment is not necessary. So, if your accident does not have airbag deployment, does this mean that there is no impact-related data recorded by the ACM? This is a question that we get a lot from attorneys, adjusters, and even curious and inquisitive citizens who call us. The answer is complicated because in most cases, there will be data, but not always. This is because of a couple of reasons: Reason 1: The impact did not “wake up” the ACM. In many minor collisions, the ACM will not be aware that an impact took place. This is because most ACM’s are not programmed to even record data below a certain threshold. This threshold is commonly 5 mph. In other words, an impact that produces a change in speed of less than 5 mph will not record data. Some ACM’s are different than others, however, and could have a different threshold than 5 mph. An interesting side note: most vehicle bumper systems that conform to FMVSS 581 are designed in such a way to withstand a 5 mph impact in most cases. This screenshot shows that an event was recorded by the ACM, but it was a "Non-Deployment" event. In other words, the airbags did not fire as a result of the crash. Reason 2: The ACM is too old. Some early versions of ACM’s do not store any data without deployment. For example, many older Ford models (2000’s model years) may have some sort of recording capability, but could not be able to record data in certain impact related events. Reason 3: The impact was not head-on. Some accident scenarios will produce a 5 mph impact delta-v, however since the impact was not head-on, some component of the impact delta-v may be associated with a side impact. Therefore, since the crash pulse in split between front and side, and may not be sufficient to record any data. The graph above shows a relatively high delta-v for a non-deployment event. While the delta-v (crash pulse) was higher than 5 mph, it still was under the threshold of deploying the airbags during the crash. This decision was made by the ACM during the crash. There may or may not be data associated with your crash. The circumstances surrounding the impact and whether or not your specific vehicle are capable of recording data must be taken into consideration when deciding on whether or not to pursue a black box download. The first step, as always, is to contact us. We can help guide you through the process and look up the details of your specific vehicle in our extensive database. Thanks for reading, and Happy Friday!

Braking systems for vehicles are dependent on a series of individual components. Each of these components is important for the functioning of the brakes, allowing the vehicle to stop when necessary. Hydraulic disc brakes are common for many passenger vehicles, and are the gold standard nowadays for performance and reliability among all cars on the road. Commercial vehicle brakes are a little different; mostly because they use compressed air in the brake lines instead of hydraulic brake fluid. Brake drums at a truck’s wheels handle the actual braking duties, components that are not usually found on modern passenger vehicles but were very common in passenger vehicles 30 or more years ago. One thing is for certain: brakes serve one purpose: to slow down and stop a vehicle as quickly as possible under all circumstances. Passenger Vehicle Brakes: The time spent braking before an accident is typically done at maximum braking level. Accident reconstructionists can measure maximum braking by application of a few different methods . The main way is by measurement of tire marks. For passenger vehicles, tire marks can be an indicator of locked wheels usually by application of brakes (not considering the usage of anti-lock brake systems). These skid marks can be used to help determine vehicle speeds at the time of brake application. Typically, a vehicle that is in the process of leaving tire marks on the surface of the roadway, when all four tires are locked, will be capable of stopping from 30 mph in about 43 feet. This is useful to know when asked to determine the speed of the vehicle at the start of the skid. How does an accident reconstructionist come up with this speed? By applying a proper “brake factor” to the calculation of the skid. Brake factors have been studied extensively by many different scientific agencies based on typical tires for standard tire skids. The results of skid testing has resulted in an industry wide accepted range of values for passenger vehicle brake factor that can be used in the determination of vehicle speeds from skid marks. Commercial Vehicle Brakes: To complicate things, semi tractor trailers and other commercial vehicles do not share the same brake factors that passenger vehicles do. The industry accepted brake factor for these large trucks is on the order of only 80% of the brake factor for passenger vehicles. What does this mean? In a similar braking situation and at the same 30 mph speed as a passenger vehicle, a semi truck will take longer to stop when emergency brakes are applied. Instead of stopping in 43 feet as mentioned above, a semi truck could take almost 54 feet to stop. This means that, in a similar scenario, a semi will still be moving at a speed of about 14 mph when the passenger vehicle has stopped! The Difference: Not only are semi tractor trailers much heavier, they are also unable to stop in as short of a distance as passenger vehicles. Why is this? There are many things that contribute to the differences in stopping distance of these two categories of vehicles. However, the main reason is fairly straightforward: TIRES. Tires for a passenger vehicle will last about 30,000 to 60,000 miles on average. This is acceptable for most consumers, as it means that tires only need to be replaced every few years. Tires for commercial vehicle are designed to last a long time. In fact, it is not unheard of for semi truck tires to last 400,000 miles. In order for these tires to last longer, they are manufactured out of harder rubber that resists wear at the cost of increased stopping distance. The amount of miles that commercial vehicles are driven in a year is significantly more, therefore making it necessary to have tires that last a long time to be cost effective for shipping and vehicle maintenance. It is important to consider the differences in stopping distance between large trucks and passenger vehicles. Veritech’s team of forensic engineers is well versed in the differences between all different types of braking systems and stopping distances . We can help you understand the effects of this for your accident, so reach out to us today.