Dallas Trucking Accident Lawyer

Call NOW for a free initial consultation with a lawyer / attorney in the
Dallas area on your injury / death case.

VERY IMPORTANT!!! Remember, drivers of commercial vehicles
depend on a clean driving record to continue driving and making a
living. They will lie about what happened in order to keep their job.
BE SURE to get witnesses, police reports, take pictures if possible,
and whatever else you can do to protect your rights.

What to do if you are involved in an automobile accident:

Steps to take when you have been involved in a motor vehicle
accident

At the accident scene:
1. Call the police
2. If anyone is or appears to be injured:
a. Call an ambulance or arrange other transportation to a hospital or
a doctor.
b. Tell the investigating police officer about the injuries.
c. Cooperate fully with the treating doctor and medical staff
3. Unless your vehicle is creating the potential for another accident,
do not move it or the accident debris until you are instructed to by
the investigating police officer.
4. Do not discuss the accident with anyone other than the
investigating officer, your doctors, your own insurance
representatives and your lawyer. Cooperate completely with the
police.
5. Make notes of any statement made by the driver or any occupants
of the other vehicle as to how the accident occurred.
6. Get the name, address, telephone number and automobile
insurance information from the driver of the other vehicle.
7. Get the names, addresses and telephone numbers of any witness
to the accident.
8. If you believe the other driver may be under the influence of drugs
or alcohol, tell this to the investigating police officer.

After leaving the accident scene:
9. Telephone a lawyer who is experienced in handling personal
injury cases. Most lawyers handle accidental injury cases on a
contingent fee basis - that means they are paid only if they win your
case and you collect.
10. Telephone your insurance agent.
11. Take photographs of the damage to your vehicle.
12. If your experience pain or other symptoms after the accident,
see your doctor
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INFORMATION:
Truck Accident Models
Truck accidents have become an important safety issue in recent
years in many parts of the United States. Between 1980 and 1989,
truck travel mileage in the United States increased by approximately
50 percent. In addition, the Surface Transportation Assistance Act
(STAA) of 1982 allowed longer and wider trucks to travel on the
designated national highway network. Major safety questions that
still exist include: (1) Are current highway designs adequate to
accommodate increased truck travel and larger trucks? and (2)
Which highway designs pose the most serious threats to truck
safety?

Using data from the FHWA’s Highway Safety Information System
(HSIS), two recent studies have attempted to address the safety
questions of larger trucks. A Federal Highway Administration
(FHWA) study at Oak Ridge National Laboratory developed
preliminary statistical models relating the truck accident
involvement rates for three roadway types and for various
geometric and traffic variables.(1) Research as part of a Grants for
Research Fellowships Program (GRF) study developed truck
accident models for Interstates and two-lane rural roads as a
function of relevant geometric features.(2) The following is a
discussion of the results of the two studies.

State Data Bases Used

Both studies relied upon data from the Highway Safety Information
System (HSIS) data base for developing relationships between truck
accidents and highway design variables. Because truck exposure
data in HSIS are not currently given by truck type, the Oak Ridge
study employed the Highway Performance Monitoring System
(HPMS) as a supplementary data source whenever exposure data
by truck type were needed.(1)

For the Oak Ridge study, HSIS data from Utah and Illinois were
selected for analysis. According to the authors, these States had the
most complete information on highway geometric design, especially
on horizontal curvature and vertical grade. For both States, accident-
related files (i.e., accident, vehicle, and occupant) were available
annually from 1985 to 1987. The Utah roadlog file containing
roadway cross-section data was available from the years 1985,
1986, and 1987, while the horizontal curvature and vertical grade
files were only available from 1987.

Since horizontal curvature and vertical grade usually change very
little over the years, the authors used the 1987 curvature and grade
data for all 3 years of road sections under the roadlog file. The
Illinois roadlog file for 1987 was used. Both Utah and Illinois have the
variables required for this study. The authors found the curvature
and gradient variables to be more complete for Utah, so the study
used only Utah data.

Analysis Methods

In the Oak Ridge study, the authors developed a Poisson regression
model to establish relationships between truck accidents and
geometric design variables. For a particular roadway type, the
number of trucks involved in accidents on each road section over a
period of time was assumed to be Poisson distributed.

The authors then presented a "negative binomial regression" model
to address the uncertainties associated with the Poisson
regression model. In the (GRF) study, a linear model and two non-
linear regression models were tested. A stepwise SAS procedure
was used to determine which variables were significant at the 0.05
level of confidence. The values obtained from the regression
coefficients were then used in a non-linear equation fitting
procedure.

Results

A. Oak Ridge Study
In the 3-year period encompassing the Oak Ridge study (1985
through 1987), there were 933 large trucks involved in accidents on
rural Interstates in Utah; 1,177 on urban Interstates and freeways;
and 685 on rural two-lane undivided arterials.(1) These values
translate into 0.88, 1.86, and 1.45 truck accident involvements per
million truck miles (0.55, 1.16, and 0.90 truck accident involvements
per million truck kilometers), respectively. For Illinois, the truck
accident involvement rates per million truck miles (and kilometers)
were 0.46 (0.29) on rural Interstates, 5.82 (9.37) on urban Interstates
and freeways, and 3.13 (5.04) on rural two-lane undivided arterials.

The number of trucks involved in accidents and the associated
involvement rates are shown in Table 1 by truck configuration and
by accident severity for Utah. For most categories specified in Table
1, combination trucks had higher accident involvement rates than
single-unit trucks. Under dark conditions, a higher proportion of
accidents involved combination trucks rather than single-unit trucks
(48.8 percent vs. 28.4 percent, respectively, on rural Interstates).

The authors derived a Poisson regression model for each of the
three roadway types. Overall, Average Annual Daily Traffic (AADT)
per lane and horizontal curvature were found to be significant for all
three roadway types at the 5-percent level of confidence. Vertical
grade was significant only for rural Interstates. Shoulder width was
significant for urban Interstates and rural two-lane undivided
arterials.

B. Graduate Research Fellowship Study
This study found that trucks are more involved than other vehicle
classes in property damage accidents and serious accidents, as
well as in four accident types (run-off-road, overturning, sideswipe,
and single vehicle).(2) Variables found to be significantly related to
truck crash involvement rates on Interstate routes included AADT,
truck volume, horizontal alignment, and vertical alignment. On rural,
two-lane roads, variables significantly related to truck crash rates
included AADT, truck volume, shoulder width, and horizontal
alignment. All variables in the models are significant at the 0.05 level.

Study Implications

Accurate estimates of truck accident rates for different truck
configurations under varying geometric conditions are needed to
understand the relationship between highway design and truck
safety. In these two studies, preliminary models were developed to
explain the relationship.

The two studies collectively revealed that a number of traffic and
roadway features can result in increased safety problems for large
trucks, as summarized as follows:

Rural Interstates

* AADT per lane
* truck ADT
* horizontal curvature
* vertical grade

Urban Interstates and Freeways

* AADT per lane
* truck ADT
* horizontal curvature
* vertical grade
* shoulder width

Rural, Two-Lane Undivided Arterials

* AADT per lane
* truck ADT
* horizontal curvature
* shoulder width

Note that truck average daily traffic (ADT), total traffic AADT, and
horizontal curvature were significant variables for all three types of
roadway classes. Vertical grade was also a factor for rural and
urban Interstates, while shoulder width was a factor on rural two-
lane roads and urban Interstates and freeways.

Based on this type of information, sites could be identified with
severe horizontal and vertical alignment, narrow shoulders, high
volumes of truck traffic, and/or other factors (as given above) as
candidates for high truck crash experience. Such information can
be used by highway designers and safety engineers to make
appropriate roadway improvements and thus reduce the potential
for truck accidents on selected roadway sections. These models
could be improved if more complete truck volume and truck
accident data (e.g., truck width, length of trailer, and overall truck
length) were to become available.

For More Information

To obtain more information on either study or on the HSIS, contact
Jeffrey F. Paniati, HSIS Program Manager, at (703) 285-2568.

References

1 Miaou, S.; Hu, P.; Wright, T.; Davis, S.; and Rathi, A. "Development of
the Relationship Between Truck Accidents and Geometric Design,"
Federal Highway Administration, August 1991.
2 Mohamedshah, Y.; Paniati, J.; and Hobeika, A. "Truck Accident
Models for Interstates and Two-Lane Rural Roads," Federal Highway
Administration, January 1992.