1. Stopper & Associates, LLC Motor Carrier Safety / Highway Collision Research & Reconstruction Nationwide Commercial Motor Vehicle Investigations

2. Stopper & Associates, LLC Truck & Bus Collision Investigations Federal Motor Carrier Safety Regulation (FMCSR) & Commercial Drivers License (CDL) compliance

3. Forensic Mapping Laser “Total Station” measurements
Forensic Mapping Laser “Total Station” measurements. “Reflectorless” unit allows detailed scene diagramming without interference with normal traffic flow.

4. Fatal Collision Involving 2 Chemical Tankers

5. Forensic Map with Reconstruction Analysis Rollover – Fatality involving two fuel tankers

6. Forensic mapping of School Bus -Refuse truck multiple fatal

7. Forensic mapping of crash vehicle & exemplar vehicle

8. Forensic - Computer Impact Analysis

10. Crash Scene Forensic Mapping & Reconstruction Analysis

11. Forensic map / Satellite Photo Overlay of Crash Scene

12. Portable Performance Based Brake Testing
Portable Performance Based Brake Testing* Vehicle weight, brake balance, air pressure and brake force testing *49 CFR (a)(4) approved test method

13. PBBT Testing– Transportation Research Center (TRC) – East Liberty, OH

14. PBBT Testing Accident Reconstruction Conference Houston, TX

15. Stopper & Associates, LLC PBBT - Brake Testing – Bus Involved in Rollover – Multiple Fatalities New Brunswick, Canada

16. Commercial Vehicle Brake Testing & Crash Reconstruction Training

17. Stopper & Associates, LLC Training Law Enforcement & Collision Reconstruction Specialists in the USA & Canada

18. David Stopper holds a CDL for all classes of Commercial Motor Vehicles and is a registered USDOT Motor Carrier

19. Stopper & Assoc., LLC Mobile Forensic Lab & Incident Response Unit

20. Fatality involving multiple brake failures Case Study Investigated by NTSB & Stopper & Assoc., LLC
National Transportation Safety Board, Collision Between Truck-Tractor Semitrailer and School Bus Near Mountainburg, AR on May 31, 2001, NTSB/HAR-02/03; PB ; Adopted September 4, 2002.

24. Air Brake Examination

25. Type 30/30 Brake Chamber & Automatic Slack Adjuster

26. Federal Motor Carrier Safety Regulations
49 CFR requires CMV maintained to applicable standards
49 CFR requires Automatic Brake Adjusters on CMVs manufactured on/after 10/20/94.
49 CFR (c)(1) requires ABS on air brake truck tractors manufactured on/after 3/1/97
49 CFR (c)(2) requires ABS on air brake trucks, buses & trailers manufactured on/after 3/1/98

27. Brake adjustment indicator 49 CFR 393. 53(c) Air Brake Vehicles Mfg
Brake adjustment indicator 49 CFR (c) Air Brake Vehicles Mfg. After 10/20/94

29. Type C- 30 (Clamp Type) Air Brake Chamber Application Force Chart

30. NTSB reported:
“A broken spring, which is difficult to detect, can reduce emergency-parking brake forces or render the emergency-parking brake inoperable, and the broken spring pieces can be displaced, thus shortening the pushrod stroke or preventing the automatic slack adjuster from functioning. The extent of the broken spring problem is undetermined.

34. Conclusions
It has become apparent there is a general lack of knowledge as to the critical nature of proper installation, lubrication and periodic inspection of these critical safety devices.

35. Conclusion
It is very important that collision investigators and CMV maintenance personnel be trained and become familiar with the operation and critical factors that can render ASA / ABAs inoperative leading to diminished brake force and/or brake failure.

36. Conspicuity Investigations
Stopper & Associates works with internationally know experts in night time & low light visibility crashes
Worked with motor carriers to install retroreflective materials for safety before it was required by law
Stopper & Associates is unique in its ability to analyze and measure the condition of retroreflective surfaces.

37. CONSPICUITY ARE YOU SURE OF WHAT YOU ARE SEEING?

38. CONSPICUITY
A MEASURE OF THE LIKELYHOOD THAT A DRIVER WILL NOTICE A CERTAIN TARGET AT A GIVEN DISTANCE AGAINST A CERTAIN BACKGROUND
Ref. NHTSA Driver Performance Data Book

39. Contrast
The ratio of luminance from a target to the luminance from the target’s surroundings

40. Contrast
The ratio of luminance from a target to the luminance from the target’s surroundings

41. Contrast
The ratio of luminance from a target to the luminance from the target’s surroundings

42. Contrast
The ratio of luminance from a target to the luminance from the target’s surroundings

43. FMCSA Recognizes benefits and requires a retrofit regulation:
Retroreflective Sheeting on Commercial Motor Vehicles
Duty of Motor Carriers:
49 CFR § Retroreflective sheeting and
reflex reflectors,
requirements for semitrailers and trailers
manufactured before December 1, 1993.
Motor carriers operating trailers,
other than container chassis (as defined in §393.5),
have until June 1, 2001,
to comply with the requirements of this section.
Motor carriers operating container chassis had until December 1, 2001,

44. Conspicuity Issues Passenger vehicle vs
Conspicuity Issues Passenger vehicle vs. semi trailer Under ride crashes (This crash occurred before sunrise)

45. David Stopper Measuring Reflectance with Gamma Scientific Model 922 Retroreflectance Meter Fatal Night Trailer Under Ride Crash

46. RETROREFLECTIVE MATERIAL VS REFLEX REFLECTOR
Refelex reflector – plastic prism
Reflex reflector – fades rapidly to observer at approximately 20 – 23 degree angle to light source / observer
Retro reflective material wider angularity – drops 50% or more at 45 degree angle to light source / observer
Both dependant on radiance or luminous intensity (brightness) of light source.

47. Model 922 Retroreflective Meter

48. Retroreflective Materials
Many motor carriers combine
reflective materials with advertising as well as the required red/white pattern retroreflective tape

49. CONSPICUITY
A MEASURE OF THE LIKELYHOOD THAT A DRIVER WILL NOTICE A CERTAIN TARGET AT A GIVEN DISTANCE AGAINST A CERTAIN BACKGROUND
Well maintained retroreflective tape improves safety and has saved lives

50. For more information on investigations or training:
David A. Stopper Juli R. Stopper Stopper & Associates, LLC Motor Carrier Safety – Highway Collision Research & Reconstruction
Washington, DC Area Office 6200 Evergreen Mountain Road Broad Run, VA Fax
Midwest & Southwest Operations – (Direct inquires to VA Office)
Texas & Pacific Railroad Building
221 W. Lancaster Avenue Suite 11008
Fort Worth, TX
Mobile: Office: