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The distance, velocity and acceleration characteristics versus time of heavy trucks for use in accident reconstruction have been the subject of studies by Grimes and others. To date, the majority of the research has been done using tractor-semitrailers equipped with standard transmissions. In recent years, as transmission technology has improved, automated and automatic transmissions are becoming popular on North American roadways. A series of tests were performed to document the acceleration characteristics of two different tractors, a 2007 Volvo VNL and a 2011 Freightliner Cascadia, both equipped with automated transmissions towing both empty and loaded semitrailers. The vehicles were instrumented with a Racelogic™ VBOX III GPS data-logging device that measured speed. Other vehicle parameters were logged using the recording software manufactured for the specific engine manufacturer.

Collision data stored in the Airbag Control Module (ACM) of some Chrysler vehicles has become available to accident investigators through the Bosch Crash Data Retrieval (CDR) system, beginning with the 2005 model year. An event data recorder (EDR) that can record pre-deployment vehicle speed and other parameters such as brake pedal application and throttle application is incorporated into the ACM, or Occupant Restraint Controller (ORC) using Chrysler terminology. The accuracy of this data under different driving conditions has not been extensively tested and reported. The primary purpose of this paper is to evaluate the accuracy of the data recorded in the Chrysler ACM under test conditions. Establishing the reliability of this information is important, if it is to be relied upon by the investigator. These results can be used to quantify the accuracy of ACM reported pre-crash data for use in engineering analysis of automobile crashes.

Electronic Control Modules (ECM) on Heavy Duty truck engines have the ability to control or monitor important engine and vehicle parameters. Examples of these parameters are fuel consumption, cruise control operation and oil pressure. Under certain conditions, many can also record parameters that are useful in accident reconstruction. Cummins engines are commonly found on highway tractors on the road today. In a heavy vehicle equipped with a Cummins engine, a hard brake application or a collision with an object can create a Sudden Deceleration Data (SDD) Report on the ECM. Since this data reports second-by-second speed information, it can be very useful in the analysis of an accident. Establishing the reliability of this information is important, if it is to be used by an accident investigator. This paper explores the data recorded on a Cummins engine ECM created during a series of acceleration, cruising, and braking tests.

The Electronic Control Modules (ECM) installed on heavy truck engines record data during normal operation. While their primary purpose is to control the mechanical and electrical systems on the engine, they monitor other vehicle systems as well. Stored data from the ECM can be downloaded into reports that are useful for tracking fleet performance, scheduling maintenance or troubleshooting engine problems. Many of the current production heavy trucks also record event information that may be useful when analyzing or reconstructing accidents. It is not uncommon for a vehicle involved in a frontal accident to experience sudden decelerations and/or sustain damage to the coolant system or rupture the oil pan. Sustained data outside normal operating parameters from sensors on the engine will typically trigger the ECM to generate a fault code. On a Caterpillar ECM, a short event record called a Diagnostic Snapshot may also be generated with a fault code.