DRIVE 2008 - Users

HUMAN FACTORS CLASS

ACCIDENT DYNAMICS RESEARCH CENTER

Developers of the 1st Empirically Derived Driver Response Times Estimation Methods

Above: Nighttime recognition research. Below: Eye tracking during vehicle following task in simulator research at UMASS Human Performance Lab

If you have been asked to evaluate the response time of a driver who was in a crash, can you answer the following questions? If not, you may want to attend our next class. Perception-reaction time starts________________ and ends ____________________. True or False. Research has established that 1.5 seconds is the standard reaction time for drivers in most situations? If five different studies measured the daytime response times to path intrusion situations and the resulting response times range from 0.6 to 1.9 seconds (which is true), you should do the following Use the study or studies that were done on real roads and ignore simulator studies. Make mathematical adjustments to each study to account for methodology and scenario differences. Use only the peer reviewed publications and use those as a range of possible response times. You cannot use any of these studies because research subjects are highly alerted and in real life response times will be higher. You cannot use any of these studies because research subjects know they will not be injured or die, therefore in real life they respond much faster. True or False. Summala, Lamble & Laasko (1988) conducted a thorough study of response times to a lead vehicle under various conditions. This study would be useful as a baseline ONLY if evaluating the response to a lead vehicle or possibly a head on situation. Since we do not have an EEG read out from the driver at the time of the crash, how do you determine when “perception” occurred? A driver is in the left lane on a road with a raised median divider, a car intrudes into his path from his right; the crash can be avoided by swerving left or right. Which response choice is this driver likely going make? The driver who you are investigating is traveling 30 m/s (98 f/s) at night.  You have utilized accepted methodologies to determine that parts of the object he struck were visible from 200 m (656 feet) away, you have used peer reviewed studies of driver response times and accounted for differences in methodology from the research and your case and you concluded that the driver should have started skidding 146 m (479 feet) from impact.  List two major flaws with this analysis? For ANSWERS

Our Background Services Curriculum Vitae of Jeff Muttart Fees Retainer Agreement HUMAN FACTORS CLASS Lectures & CLASSES Research Papers Night Visibility Driver Response Time Charts Speed calculation Chart Definition of Accident Reconstruction Projects at UMASS UMASS Human Performance Lab Disclaimer Contact Information

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Background of Jeffrey W. Muttart. . .

Jeff Muttart has been reconstructing motor vehicle accidents for over 20 years and here are some accomplishments.  

1. Assigned the title “Accident Investigative Reconstructionist” by the Groton Town Police in 1985.

2. Taught accident investigation at Three Rivers College.

3. Completed college and training courses that amount to over 2,000 hours (an average of 1 hour every day for 4 1/2 years and this does not include independent research).

4. Started "Accident Dynamics Research Center" in the summer of 1990. (We believe the name of the firm explains what we do.  We collect scientific research or conduct our own research to determine the causes of a motor vehicle collision, a dynamic event).  

5. Became a fully accredited traffic accident reconstructionist after he passed both the written and practical portions of the rigorous 8-hour exam offered by the Accreditation Commission for Traffic Accident Reconstruction [ACTAR].

6. Completed a Masters degree at the University of Hartford where his studies have focused on driver and pedestrian response.

7. He is has developed and validated mathematical equations from previous perception-response research that predict average driver response times under various conditions within 0.4 seconds when compared to the responses of real world crash (and near crash) victims (Published by the Society of Automotive Engineers Paper No. 2003-01-0885).

8. Inducted into Psi Chi National Honor Society (3.94 grade point average out of 4.0).

9. Author of over 20 research papers and articles in scientific journals.

10. Lectured to Insurance Companies, Government (and police) agencies, Colleges, accident reconstruction organizations and investigative organizations throughout the US and in England, Canada, Poland and New Zealand.

11. Lectured at the largest accident reconstruction exposition ever held (WREX 2000) at Texas A&M University in September 2000.  

12. Invited to the National Highway Traffic Safety Administration to present his research findings to the Sub-committee for the development of standards for high visibility clothing.  That committee developed standard ANSI-ISEA 107-1999. 

13. Recipient of the William S. & Dorothy G. Wallace Award for Outstanding Research.

14. Awarded Graduate Research Award 2001-2002 from the University of Hartford.

15. Developed DRIVE (Driver Response in Various Environments) algorithms that have been internationally recognized and allows the user to estimate the response times of drivers in various circumstances.

16. Author of the chapters in two books.

17. Awarded Research Assistantship in the Human Performance (Driving Simulator) Laboratory at the University of Massachusetts. Enrolled as a Ph.D. candidate in the Mechanical and Industrial Engineering Department.

With over 20 years, our accident reconstruction work has survived intense scrutiny during depositions, discussions and trials. Mr. Muttart has been recognized as an “Expert Witness” in Superior Courts in several states. This is primarily because Mr. Muttart believes (as does the U.S. Supreme Court in their recent rulings) that his opinions should be obtained using accepted scientific methods. To do this we conduct independent research and obtain additional training on a yearly basis. We do not “dabble” in the field. Our integrity does not stop with establishing a proper scientific methodology for our conclusions. We also believe in giving our clients an honest assessment of how a collision occurred, and a fair amount of work for their money.

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TRAFFIC ACCIDENT RECONSTRUCTION SERVICES

Since 1983, Mr. Muttart has reconstructed over 1,000 motor vehicle accidents for both plaintiff and defense counsel.  He has worked cases or lectured in more than 30 states and four countries. He has testified regarding issues in the following accident reconstruction related topics:

þ	Anthropometric traits of driver response in motor vehicle crashes.
þ	Visual attention.
þ	Visual conspicuity of hazards.
þ	Effects of driving under the influence on driver response.
þ	Factors influencing driver and pedestrian response.
þ	Contribution of highway signing and design in motor vehicle accidents.
þ	Highway design and traffic control systems (as it relates to a crash).
þ	Standards for roads, vehicles and parking lot (as it relates to a crash).
þ	Matching injuries to their cause.
þ	Occupant displacement relative to speed changes.
þ	Analysis of vehicle dynamics.
þ	Movements of occupants and pedestrian during an impact (kinetics/kinematics).
þ	Pedestrian accidents.
þ	Bicycle collisions.
þ	Demonstrative and visual aids, including animation.
þ	Analysis of seat belts restraint system usage and application.
þ	Vehicle damage analysis.
þ	Speed determination from skid marks; vaults, momentum and vehicle crush analysis.
þ	Motorcycle accidents.
þ	Bulb and lamp examinations.
þ	Time and distance (spatial relationship) calculations.
þ	Area of Impact Determinations.
þ	Vehicle avoidance issues.

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ADDRESS:

Accident Dynamics Research Center

P. O. Box 261

Uncasville, Connecticut 06382

(860) 848-8782

Fax (860) 848-2526

e-mail: jmuttart at accidentdynamics.com

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PATH INTRUSION RESPONSE TIMES 

Definition of Terms:

Do not use this chart until the object/vehicle/pedestrian/bike... was not easily identifiable as an immediate hazard.

Stimulus: A “stimulus” as defined in this research is something the driver was responding to.  Therefore, if there are 5 other cars, 2 birds, 4 pedestrians and one of them come into the driver’s path, then that would be a response analysis for a response to one stimulus.  A multiple stimulus event is if the driver was responding to one object and 0.1 to 1.0 second later, he or she was expected to respond to a second object.  The first object could be a car, dialing a cell phone, or anything else that required a response.

Straight versus Curve/Cue/Intersection: Straight means there were no changes in elevation in the immediate area.  You could have a straight upward grade, flat grade or downward grade (less likely).  Otherwise, select Curve/Cue/Intersection if responding (or expected to respond) after the knoll of a hill, entering or within a curve in the road or entering or within an intersection.

Day or Night: Select Day if before sunset, night if after sunset and if dusk, look at the range between column for "Day" and "Night".

Eccentricity: The number of degrees from straight ahead from the subject driver to the closest portion of the intruder or intruding vehicle when that intruder crossed the stop line or analogous location.

From a stop: If the Subject driver (responder?) never saw the intruder stopped, then use the lower portion of the chart.

Lanes: Number of lanes from which the intruder emerged from in a continuous motion.  For example, if a vehicle cut from the left lane all the way to the right lane on a highway with three lanes, enter "Multiple Lanes".  If that same vehicle moved first to the center lane, then swerved from the center lane into the right lane (in a stair-step movement), use "One Lane".

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This chart estimates the average response time for each scenario within 0.5 seconds.If a study reports a number significantly different than that listed above, compare the methodology of the study with that of your case (The methodology of the study is likely different).

 This chart offers average response times of drivers based upon the variables listed. DRIVE³ [Driver Response in Various Environments Estimated Empirically] is a computer program offered by several computer programmers that accounts for several more variables.

It is extremely important to understand that these are PERCEPTION-RESPONSE times. Therefore, apply these numbers only after a point when the object should be easily perceived as an immediate hazard. Not only do these times assume perception, they also include vehicle response. These are not “reaction” times; a reaction is the first movement in response to a stimulus (as with taking your foot off the throttle). These numbers represent a time period from perception until first VEHICLE response (the very first lateral movement in a steer or the start of a skid mark [or similar location] for a braking response).

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VEHICLE FOLLOWING RESPONSE TIMES 

To calculate the threshold for determining when a driver is likely able to recognize the rate that they are closing on a lead vehicle, use the following equation and apply a response time from that location (given no adequate context to judge closing speed [be prepared to explain why you believe there was not adequate context]).

 If you use a different "Perception" threshold (than that given by this equation), then you should also use a different PRT.

If within this distance simply apply response times below.

This chart will underestimate response times if the lead vehicle has no lights on at night. If a study reports a number significantly different than that listed above, compare the methodology of the study with that of your case (The methodology of the study is likely different).

Response times assume full braking of a passenger car. Make adjustments (up) for air brake systems and (down) if the driver reports that his foot was hovering over the brake pedal (or in some way the driver reduced the motor response time).

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Projects at the UMASS Human Performance Laboratory

The Drivers in Work Zones and with Cell Phone (Simulator and Road Research)

Sponsor: New England Coalition of DOTs

Search Behavior of Novice Drivers (Simulator and Road Research)

Sponsor: National Highway Traffic Safety Administration

Ice Sensing Technologies for the Tobin River Bridge

Sponsor: MassPort

Abilities of Parking Assist Technology as a Crash Avoidance Tool

Check out the other research at the Human Performance Lab

http://www.ecs.umass.edu/hpl/

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LEGAL DISCLAIMER

The Accident Dynamics Research Center [ADRC], Jeffrey Muttart and Webb Designs provide general information that is intended, but not guaranteed, to be correct and up-to-date. The information is not presented as a source of legal advice. You should not rely, for legal advice, on statements or representations made within the Web site or by any externally referenced Internet sites. If you need legal advice upon which you intend to rely in the course of your legal affairs, consult a competent, independent attorney (who will decide if a traffic crash reconstructionist is appropriate for your case).

Although great effort has been expended to ensure that only the most meaningful on-line legal resources are linked from these pages, ADRC, Jeffrey W. Muttart and Webb Designs of CT do not endorse, guarantee or warranty the accuracy, reliability or thoroughness of any referenced information, product or service. Any opinions, advice, statements, services, offers or other information or content expressed or made available by third parties are those of the respective author(s) or distributor(s) and do not necessarily reflect those of ADRC, Jeffrey W. Muttart and Webb Designs.

Links either to or from our Web pages do not constitute a referral. The existence of any particular link is simply intended to imply potential interest to the reader.

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Experienced driver negotiating a Curve to the right

Inexperienced driver negotiating a curve to the right