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Traffic & Transportation Engineering
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Road Design & Construction
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Traffic Control Devices
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We have testified on numerous issues involving permanent or work zone (maintenance / construction) traffic control. Having contributed to the two most important Traffic Engineering publications in the country, the Manual of Traffic Control Devices and the Traffic Control Devices Handbook, we have a unique posture in the field of Traffic Engineering. In addition, the Federal Highway Administration has a certification/testing program for design and application of work zone traffic control, which each of our Engineers has successfully completed. In addition, we are a member of the Transportation Research Board and have been a part of the "Traffic Control Devices" committee, and are currently part of the National Committee on Uniform Traffic Control Devices committee (which writes both Federal and State Standards for Traffic Control Devices, including the new Caltrans Traffic Manual.)
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Run Off Road Accidents
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The Federal Highway Administration (FHWA), the American Association of State Highway and Transportation Officials (AASHTO), and others have been active in recommending safe slopes for run off road vehicles for more than 60 years. Since the 1930's, a slope that is steeper than three to one (3 feet out and 1 foot up) up to a four to one slope has been considered TRAVERSABLE (a driver can safely traverse this slope traveling in a more or less straight line). To be RECOVERABLE (a driver can steer back to the road on the slope) the slope must be at least four to one. Both FHWA and AASHTO have sponsored "Embankment Traversal Tests" and computer simulation development based on much of that testing starting in the 1970's to scientifically and experimentally test this hypothesis.
Several test facilities throughout the country have participated in providing data with specially equipped vehicles such as that shown in the photos below, which is used to provide acceleration, braking and steering to vehicles in the embankment traversal tests.
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| Braking, Acceleration and Steering Equipment for Embankment Traversal Test Vehicles |
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The tests below have confirmed that the 3:1 to 4:1 slopes are traversable, but not recoverable. The photos below depict a 2,000 pound test vehicle that was steered to attempt a recovery on a 3 or 3½ to 1 slope.
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Since 1988, FHWA and AASHTO have used the "Roadside Design Guide" as a comprehensive guide on barriers, side slopes and clear zones.*** An instructional course was taught throughout the United States on the design of roadside or off the road facilities such as Guardrail, Barriers and Side Slopes, to eliminate and prevent accidents resulting from run off the road vehicles.
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***Generally - a clear zone is an area of clear recovery area not including any areas considered traversable (but not recoverable) to allow an errant vehicle to recover and return to the road.
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This "Vehicles on Slopes" video clip below was taken from the FHWA course on use of the "Roadside Design Guide."
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Guard Rail and Other Barriers
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Guard rail and other barriers, when installed and properly designed, are life saving safety features of many roads. When they are not installed correctly, or are installed in the wrong application they can act as obstructions and can be dangerous. The video below, as an example, shows a guard rail installation that is very common to California (although not currently used.) This is from a Federal Highway Administration tape on proper use of the "Roadside Design Guide," currently accepted as the one standard in all states for barriers and attenuators, as well as side-slopes of roadways.
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We have literally thousands of Test Reports and Videos from vehicle and barrier testing. Our secondary source is lodged in Washington, DC and contains vehicle or barrier tests from every recognized research organization made in the last 40 years.
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Wet Weather Accidents
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Our firm has been involved in wet road accident testing and analysis since 1997, when we became the only private organization to own a full size "skid" test trailer in Southern California. Again, we have provided services to attorneys representing both agencies and plaintiffs in several major wet weather accident suits. We also have a relationship with the ASTM E17.21 committee, which is responsible for pavement / tire interactions in wet or dry weather. As such we are able to determine if the wet roadway complies with State and National standards for wet friction coefficients. Also, we can provide an accurate friction constant for the all so important speed calculations in accident reconstruction. We have worked closely with several accident reconstructionist firms to provide coefficient of friction and perception reaction times. (The photo above shows our skid trailer equipment).
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Hydroplaning is a unique feature which can be influenced by the tire, the road and the amount of water. The road agency usually will design the road so that water will drain off the road in almost any storm. A proactive agency will prevent roads from becoming excessively slick. A good set of tires should then keep you from losing control in wet weather (rather than what happens in the film clip below). Most people blame themselves for skidding in wet weather. Unfortunately, in some cases, the road may be the reason, or someone may inappropriately point a finger at the road. Our testing and expertise can help defend your agency or help prove your claim in wet weather accidents.
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Portland Cement or "White" Concrete, when used as a road surface, is sometimes thought to last "forever," and is often "grooved" once it starts to wear in order to provide an adequate wet weather surface. The grooves shown here provided a nice sharp surface for wet weather when they were new, but these (from I-10 across downtown Los Angeles - known as the busiest freeway in the world) are obviously worn and "rounded." Grooving, unfortunately, can only be done once.
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Geotechnical / Environmental / Materials Engineering
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There are three primary Materials that make up all roadways, walkways and parking facilities. Our experience includes the control of materials on projects as lead materials engineers on numerous major transportation projects.
The most common of the three materials is the soil which makes up the "base" of every road, walkway or parking facility. Even those soils placed adjoining the asphalt or concrete on the side of the road must meet stringent hardness or compaction requirements. This can be a critical component in allowing an errant vehicle to safely return to the road.
This hardness is intended to last or be maintained throughout the life of the road. This can be critical to vehicle stability when an emergency movement forces a vehicle off the road.
Asphaltic Concrete is another common transportation material. This material is simply dried, properly screened and graded "soil" with an asphaltic cement added.
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Since soils are the foundation of the roadway, failure in the soil foundation often means ultimate failure of the finished road.
A "slippery" condition inside of a tunnel in northern California was the result of a combination of wet soil with an oily residue that was shown to exist in the tunnel's natural soil foundation from documents provided from the environmental studies prior to the tunnel construction.
We have testified on numerous Portland Cement Concrete, Asphaltic Cement Concrete and Soil Materials related matters. The surface of a facility can provide the answers to questions relating to many failures or inadequacies. But occasionally a more "in depth" analysis is necessary. We are at the forefront in both surface and subsurface investigations of transportation materials!
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Speed Surveys
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A reliable speed survey can be used to prove reasonableness, as well as to establish the speed that should be posted. The process is specific and provided for in most state's (including California) Vehicle Codes. We have testified in numerous matters dealing with appropriate speeds of vehicles (we testified in one trial ONLY to establish the speeds of loose and rolling rail cars near a rail / shipping facility on the docks in L.A.!)
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Deposition, Trial, and Discovery Consultation
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Our firm has a significant advantage in providing deposition, trial and discovery information to the attorney. All of our engineers have extensive experience in several state department of transportation's and have helped to defend them in numerous litigation matters.
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Robert Douglas has been active in deposition, trial and discovery preparation since 1987, when he was Arizona Department of Transportation Forensic Engineer. There he worked with the State Attorney General's office in laying out the defense for tort trials against the department.
After coming to California, he maintained an interface with Caltrans' legal counsel until leaving Caltrans in 1994 to pursue full time litigation support for plaintiff and defense. After participating in defense trials for several years, in 2002 he was asked to provide consultation for a plaintiff case, and played a lead role in discovery, deposition and trial preparation. He was present throughout this extensive defective road case, and took part in every part of the process including preparation of exhibits, witness lists, exhibit lists, motions in limine, opening statements, trial examination and cross examination and closing arguments. As such, he has a unique perspective of the process and can capably assist in many facets of the litigation process.
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Depositions are a unique part of the tort litigation process. After many years of depositions, we can not only assist in providing questions for your deponents, we feel comfortable in being prepared to answer questions while being deposed. Below are a few "out-takes" from a recently videotaped deposition.
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