In this Issue:
Marking A PathATA Offers Third Program in
"The Road Series"Paving Machine Accident -
A Technology Case StudyNew ATA Production Graphics
DVD Available
Marking A Path
by Ed Fritsch
There are three things which are too wonderful for me - the way of an eagle in the air; the way of a serpent upon a rock; the way of a ship in the midst of the sea.
(Proverbs 30:18-19)
What was it about the eagle, the serpent and the ship that brought them to the attention of the oracle in the Book of Proverbs and what was it that made them, in his estimation, too wonderful? At the very least, it is that none of these things leaves behind any sort of lasting trail for a curious investigator to follow. So it was 2600 years ago and so it is today with the trajectories of most objects that move through our physical environment. Occasionally, we may find skid marks at the sites of certain traffic accidents, and those marks may yield some information about the motion of the skidding vehicle; but skid marks are left only in a certain portions of a specific limited class of accidents. In most accidents, the complete trajectories of the vehicles involved must be reconstructed almost entirely through theory and analysis.
In physical re-enactments of vehicular accidents using exemplars, accelerometers are typically used to observe and record vehicle motion. From an acceleration record, a velocity history can be mathematically derived, and from the velocity a position history describing the vehicle's trajectory can be extracted. However, if accurate position data is to be derived from acceleration, special care must be taken in calibrating the accelerometers prior to the test and exhaustive mathematical manipulations must follow. Because of the attendant difficulties in accurately determining position from acceleration data, the path through space of a vehicle in a re-enacted accident may never be described, or if it is, it may only be incompletely or qualitatively described by a video record of the test, which will typically show the vehicle in relation to a few fixed landmarks within the test environment.
Recently, however, the expanded availability of satellite-based global positioning system (GPS) technology has opened new windows on the measurement and depiction of vehicle motion and location in dynamic situations. ATA Associates, Inc. has used GPS equipment to track the paths of vehicles since 2005. In that year, ATA made its first significant use of GPS technology in a project to develop training materials for one of the nation's largest trucking firms. In that project, GPS equipment was used to track 18-wheelers operating on highways and city streets in various traffic situations. The GPS location data provided a new, geographic context for the novel interpretation of typical vehicle performance data such as fuel consumption. This contextual interpretation allowed instances of both high and low fuel consumption that were recognized after-the-fact in the test records to be traced back to specific locations and traffic situations. Analysis of the truck driver's responses in those situations led to an improved understanding of specific driver habits which lead to either enhanced or diminished fuel economy.
Since 2005, ATA has also made use of GPS technology on several occasions to profile arched bridges, causeways and overpasses where line of sight issues might have influenced driver behavior in accident scenarios. The collection of three dimensional GPS location data from a vehicle moving over a long or acutely arched bridge provides a practical means for collecting critical elevation data that could be prohibitively expensive or unreasonably dangerous to collect by more conventional surveying methods.
In late 2007, ATA added to its inventory of GPS equipment a new receiver and antenna system capable of recording GPS location data at the rate of 10 samples per second. The high data rate unit has already been used successfully to quantify the maneuverability of a small motor boat and the braking effectiveness of a high performance automobile. In conjunction with recently acquired rotation rate sensors, the new GPS receiver promises to make possible the accurate recording and depiction of vehicle motions of unprecedented complexity. ATA 's growing arsenal of GPS tools and increasing skill and imagination in their use promises to make such complex motions no less wonderful, only less mysterious.
ATA Offers Third Program in
"The Road Series"
ATA is proud to announce the release of � The Road Series 3 � Level 1 Vehicle Inspections,� the newest DVD in � The Road Series� truck driver training program. The seventeen minute DVD covers the requirements of the North American Standard Level 1 Inspection Procedures and trains truckers to know what to expect during these intensive vehicle inspections. Level 1 vehicle inspections cover the driver's paperwork and examination of the entire vehicle, including the underside. The DVD walks drivers through the entire procedure, following the inspection format set by the Commercial Vehicle Safety Alliance or CVSA.
As with all � The Road Series � programs, driver quizzes and instructor guides are available as downloads from the ATA Associates website.
� The Road Series� DVDs are available at no cost from ATA Associates. Call (281) 480-9847 or visit ATA 's website at www.ataassociates.com.
ATA Assists Law enforcement
ATA provides free of charge assistance to local and state police to conduct downloading the �black box� data in accidents involving police vehicles. Our current software and hardware allows us to obtain crash data recorded information from Chevrolet, Ford, and now Chrysler vehicles. (See www.boschdiagnostics.net - CDR for the make, model and year of coverage).
On the heavy truck side, we are capable of getting information from most of the heavy truck engine manufacturers including Detroit Diesel, Mercedes, CAT, Cummins, and soon Mack. (See http://www.ataassociates.com/ECMinfo.htm for coverage details.)
More and more precincts are getting their own equipment, but the expense of maintaining and operating download hardware and software from the different manufacturers is cost prohibitive for many departments. By offering our valuable tools and human resources, ATA continues to maintain good will public relations with the first responders to accidents.
Paving Machine Accident - A Technology Case Study
by Norm Nissen
As one of the leading companies in its field, ATA Associates strives to be a single source for accident reconstruction, testing, and litigation support. Over 15 years ago, ATA created a graphics, animation, photo and video department designed to support every aspect of our clients' projects. Often, complex accidents are more clearly and dramatically visualized using advanced production mediums.
In 2001, ATA was hired to reconstruct a fatal accident involving three young boys killed after driving their car into a street paving machine on a deserted road at night. The construction company putting in a road system for a new subdivision left the paving machine parked at the end of a newly made street. The boys' car essentially under-rode the machine making direct and fatal contact with the retracted blade.
ATA 's involvement in the case began with performing both an accident site survey and testing to determine darkness and ambient light. Detailed measurements and photographs were taken of the paving machine and transformed into a scaled three dimensional model. A 3D digitizing arm was used to trace points on the actual car involved in the accident. The 3D arm captures contact points and crush measurements to an exact placement and scale. Crush measurements were used to determine the speed of travel at impact with the paving machine. A pre-impact 3D model of the car was also scaled and placed in conjunction with the model of the damaged post-impact car. Once models are created, they can be animated to strict physical actions and characteristics.
The accident site was recreated in 3D using the site survey measurements and photos taken at the scene. The ambient light, the light patterns, and intensity from the car's headlights, as well as the conspicuity of the dirty paving machine were all taken into account to create an accurate and compelling animation. The ability to put a virtual camera in any position or vantage point is a major benefit of using animation.
The animation showed what the driver of the car would have seen at the determined speed of travel and under the existing lighting conditions. The engineering analysis revealed and the resulting animation demonstrated that, unfortunately, the boys would not have seen the paving machine until a time when the impact was unavoidable. The construction company was found to be negligent at trial.
Photos, video, graphics and animation - these are the tools that ATA 's production department uses to provide litigation support solutions. A new interactive DVD highlighting ATA 's production capabilities is available at no charge via our website at www.ataassociates.com or by calling (281) 480-9847.
