At Transportation Safety Inc. as you will read we specialize in commercial truck and bus operations.

  • Preventable or Non-Preventable Accident/Incident.
  • Driver Qualification.
  • Driving Skills and Duties.
  • Negligent Hiring.
  • Negligent Retention.
  • Pre-Trip Inspection of Commercial Vehicles.
  • Driver Errors.
  • Preventative Maintenance and Inspections of Commercial Vehicles.
  • Federal Regulations regarding Commercial Vehicles.
  • Individual State Regulations regarding Commercial Vehicles.
  • Permit Loads.
  • Hazardous Materials.
  • Air Brakes, CVSA “Out of Service Criteria” and the Non-Delegable Duty to Maintain Brakes.
  • Commercial Vehicle Inspections Post-Accident, including brakes, steering, tires, seating, lighting, reflective tape and on-board recorders.
  • Federal Motor Vehicle Safety Standards.
  • Air Brake Efficiency Formula.
  • Rollovers.
  • Driver/Operator Safety Manuals and Handbooks.
  • Load Securement.
  • Off-Tracking (Trailer Cheat) and Off-Tracking of Articulated Buses.
  • Driver “Hours of Service”, log books and related regulations.
  • DOT Audits
  • CSA 2010 Audits
  • CHP BIT Audits

Trucks, Trucks and Buses

During the 1970’s and the 1980’s the U.S. Environmental Protection Agency was trying very hard to reduce the amount of toxic emissions created by motor vehicle manufactured and imported into the United States. The manufacturers of automobiles were touted by the EPA as being the largest producers of airborne emissions and the goal was to reduce those emissions in the form of smog controls and engine control modules which monitored the input of fuel and air finally the exhaust through catalytic converters.

Diesel engines were among the last to be mandated through stringent engine electronic control modules (ECMs). This advent in controlling diesel exhaust emissions evolved through much lobbying by the EPA to gain the support of the American Truck Association and the Private Truck Council. Finally in the late 1980s the involvement came into being and the diesel engine manufacturers started creating some very costly but viable solutions to mitigating the amount of heavy particulate in diesel exhaust emissions. The days of heavy black smoke pouring out of twin diesel stacks were coming to an end.

Detroit Diesel came up with their DEDEC ECM which has evolved into a very effective ECM and has decidedly reduced smog producing emissions created by their family of diesel engines. DEDEC also has an addition to some of the older units called a Po-Driver which also gives a “Hard-Braking Event recorded in detail second by second for 1.5 minutes prior to deceleration and 30 seconds after. Cummins Diesel engines have an ESP CELECT Plus with a Road Relay System. Caterpillar Diesel engines have an ECM with a CADEC unit.

These are all an accident reconstruction and investigative tool for trucking companies, bus companies, Accident-Review committees and for juries to preview in making a decision. The decision is whether the accident or incident was “Preventable” or “Non-Preventable on part of the driver, maintenance or the other driver involved.
Does the daily driver’s log reflect accurately the hours of driving or rest periods as recorded by the ECM?

All of these ECMs have a hard flash card that stores the memory until that memory is replaced by subsequent hard braking events and on-going engine hours. These internal batteries have a life span of approximately 5-9 years after the external battery has been disconnected or destroyed.

Each ECM has an individual make, model and serial number which is unique to the date of manufacture, engine installed and is forever recorded by the factory “Build Sheet” or “Line Set”.

The factory set governing parameters concerning: long-term idle “Shutdown”, maximum road speed, maximum engine RPM, low coolant level, freezing, low fuel pressure and low oil pressure, can also be sent via providers like Qualcom to the home terminal and the employer can call, text or E-mail a driver about the problem or condition.

In any event these diesel engines have a very prolific amount of information. Some diesel engine manufacturers do hold out that the information within the ECM is proprietary and restrict access to any accident download by experts and will not sell the software required.

There is one big caution in downloading these ECM modules post-accident and that is the default within the software download program automatically resets the memory in the module. If this occurs then anyone who tries to download the ECM later will have no access to the accident scenario and all of the many pages of reports, graphs and driver profiles.

In the area of accident reconstruction the future appears that it will be up to an ECM technician that will open the memory to all parties involved and most importantly it contains a “Silent Witness” in the form of the “Black Box” or “Yellow Box” depending on the manufacturer. The objectivity of the box is without question as long as the designed pre-set calibrations are correct and the tires have the same roll radius as the original set up states. If the rear end gear ratio or the transmission has been changed without being “spec’d” out and incorporated into the ECM, then the subsequent printout would be highly suspect as anywhere near accurate. Be careful that the truck and drive train are exactly as specified in the factory set calibrations.

On April 11, 2005- Court TV presented a program entitled “Truckers Nightmare”. There was an example of a Detroit Diesel ECM with a Pro- Driver unit installed in a Peterbuilt tank truck towing a tanker full of crude oil. The truck and trailer started out at 11.5 MPH on an extreme downhill grade and wound up going off a cliff at 67 MPH. There were no witnesses to this solo fatal accident near Ojai, California except for the ECM memory coupled with the Pro-Driver unit.
After years of being a truck driver, CHP officer and working truck accidents for over 42 years this was indeed a very sobering readout as I read the printout downloaded involving the last 2-minutes of a truck driver’s life.

Robert Wilson,
So.Cal. (562) 698-0040, No. Cal. (530) 363-4989,


About Us | Biography C.V. | Expertise | US DOT Compliance | Contact Us | Articles of Interest

© 2007-2015 Transportation Safety Incorporated. All rights reserved.