FEDERAL MOTOR CARRIER SAFETY ADMINISTRATION

FMCSA Contact: Joe DeLorenzo, MC-EFM-SV, (708) 283-3572

Hazardous Materials Risk

Assessment: Final Report

Introduction

As part of its efforts to promote the safe transportation of hazardous materials (HM), the

Federal Motor Carrier Safety Administration (FMCSA) sponsored a study to assess and

compare the risks posed by transporting hazardous materials and non-HM shipments in

order to assist in identifying high-risk motor carriers. The results of this research study

may be used in the development of a transportation risk assessment model, which will

enable FMCSA to identify programs that will result in the greatest improvement in safety.

Background

In Phase I of the three-phase project, researchers assessed the feasibility of conducting a

comprehensive risk study of HM and non-HM transportation. Specifically, researchers chose

one year, 1996, to look at the costs of transporting flammable/combustible liquids, which

represent more than 50 percent of all HM truck transport. The study results were

published in the Hazardous Materials Risk Assessment: Year Portrait of Hazardous Materials

Accidents/Incidents and Impacts. This process was then extended to three years of records,

1995-1997, for flammable gases (considered Class 2.1 HM) and corrosive materials

(considered Class 8 HM), which provided a preliminary estimate of the cost impact of

transporting HM shipments. 

In Phase II, which is the primary focus of this Tech Brief, researchers produced an actual

comparative risk assessment by calculating and comparing the costs and risks associated

with transporting HM and non-HM truck shipments. The third phase of the project focused

on how the HM risk information, collected during the first two phases, could be applied to

the SafeStat program to help identify potentially unsafe motor carriers.

This Tech Brief summarizes the project described in the final report, Comparative Risks of

Hazardous Materials and Non-Hazardous Materials Truck Shipment Accidents/Incidents,

2001, which is available on the FMCSA Web site at

http://www.fmcsa.dot.gov/Pdfs/HMRiskFinalReport.pdf.

Purpose

The purpose of the study was to assess and compare the calculated risks associated with

the transportation of HM and non-HM shipments. The results also will be used to assist

the FMCSA in identifying high-risk motor carriers.

Phase II Methodology

Researchers analyzed two types of HM events—accidents and incidents. An accident occurs

when a vehicle transporting hazardous goods is involved in a collision, regardless of

whether any material is spilled or released in the atmosphere. An incident occurs when a

vehicle transporting hazardous goods spills some of the cargo, but is not involved in a

collision. An incident resulting in the spill or release of hazardous materials during loading

or unloading is defined as a loading/unloading incident.

Researchers calculated the risks associated with each of the nine HM classes to obtain the

overall HM risk. The Federal Code of Regulations (FCR) lists nine classes of hazardous

materials as shown in Table 1. 

The goal of the Federal Motor

Carrier Safety Administration

(FMCSA) is to reduce commercial

vehicle related fatalities, as well as

the number of persons injured in

commercial vehicle related crashes,

by 50 percent by the year 2010. 

FMCSA's Research and Technology

programs encompass a range of

issues and disciplines, all related to

motor carrier and bus safety and

security. FMCSA defines a

"research program" as any

systematic study directed toward

fuller scientific discovery,

knowledge, or understanding that

will improve safety and security,

and reduce the number and

severity of commercial motor

vehicle crashes. Similarly, a

"technology program" includes

those that adopt, develop, test

and/or deploy innovative driver

and/or vehicle best practices, and

technologies that will improve

safety and security, and reduce the

number and severity of commercial

motor vehicle crashes. 

Currently, FMCSA's Office of

Research and Technology conducts

programs in the area of Driver

Safety Performance, Commercial

Vehicle Safety Performance, Carrier

Compliance and Safety, Safety

Systems and Technology, CrossCutting Safety Initiatives, and

Security. The study described in

the following Tech Brief was

designed and developed as part of

FMCSA's Research and Technology

Carrier Compliance and Safety

Program. The primary goal of this

program is to improve the safety

of all motor carriers—particularly

high-risk carriers—by ensuring

compliance with safety

performance regulations set forth

by the organization.

Office of Research and Technology

400 Seventh Street, SW

MC-RT, Room 3107

Washington, DC 20590

Tech Brief
2. Review several sources of information such as federal and state databases in order to establish reasonable

estimates of the economic impact of each consequence

3. Tally the cost impacts reported in Federal and state databases and other sources

4. Create models or cost impacts not readily available from sources, e.g., incident delay, which is not reported by

HMIS and other databases

5. Convert all cost impacts into dollar values to enable a financial and economical comparison among different

cost impacts to come up with a total impact value for one year

The Hazardous Materials Information System (HMIS), a database that tracks highway transportation events, was

an important source for estimating the cost impacts of accidents and incidents associated with product loss,

cleanup costs, and property damage. Injuries and fatalities were valued to be the amount the U.S. Department of

Transportation (DOT) would be willing to spend to avoid an injury or death. This averaged out to be $200,000 to

avoid an injury and $2,800,000 to avoid a fatality. Delays caused by traffic events were identified as the total

number of people delayed at an incident or accident multiplied by $15 per hour. Environmental damage was

identified as the size of an average spill plus the value of environmental contamination (determined by an

average of 30 legal settlements).

Results

Results from the study were reported in terms of Frequency, Hazardous Materials Impacts/Costs, Non-Hazardous

Materials Impacts/Costs, Comparative Risks, and Accident Rate and Cost per Mile, specifically:

Frequency

The average frequency of HM accidents for one year was estimated to be 2,484 accidents, with 768 resulting in

the release of hazardous materials. The average annual frequency of HM incidents was 1,455. The average

annual frequency for loading/unloading incidents was 10,746. 

Shipments of flammable and combustible liquids (considered Class 3 HM), as well as corrosive materials

(considered Class 8 HM) accounted for about 64 percent of total HM release accidents and 52 percent of nonrelease accidents. HM classes 3 and 8 also were involved in about 77 percent of the annual enroute incidents

where an HM release occurred, and 84 percent of all loading and unloading incidents.

Hazardous Materials Impacts/Costs

HM shipments make up between 4 and 8 percent of all transported shipments. The estimated total cost for HM

truck accidents and incidents for a period of one year is about $1.2 billion. HM accidents account for about 89

percent of the total cost impact, or $1 billion. 

Table 1

Classes of Hazardous Materials 

Class Hazardous Material

1 Explosives

• Potential for mass detonation likely

• Potential for mass detonation unlikely

2 Gases

• Flammable

• Non-Flammable

• Poisonous 

3 Liquids (flammable and combustible)

4 Flammable solids 

• Spontaneously combustible materials

• Dangerous when wet materials

5 Oxidizers and organic peroxides

6 Toxic materials and infectious substances

7 Radioactive materials

8 Corrosive materials

9 Miscellaneous dangerous goods

Completing Phase II of the project enabled the

comparison between the risks of transporting any HM

class to the risks of transporting other HM classes and

non-HM shipments. Researchers used data from a

variety of sources including federal and state

databases, local authorities and private companies. For

the final analysis, data from 1990 through the

beginning of 1999 were used to create an annual

estimate of HM impacts. To derive an estimate of the

annual economic impact of HM accidents and

incidents, a number of considerations were taken into

account including the following five-step process:

1. The following cost impacts were included in the

model:

• Injuries and deaths

• Cleanup

• Property damage

• Evacuation

• Product loss

• Traffic incident delay

• Environmental damage
Accidents that resulted in a release of hazardous materials cost $416 million and accounted for about 40 percent

of enroute accident cost impacts. While accidents that resulted in fire or explosion made up only about 12

percent of the total number of HM release accidents, they were estimated to cost $139 million, or about 34

percent of the total cost of HM release accidents. Non-release accidents made up about 60 percent of the total

annual accident cost impacts while enroute incidents with HM release and loading/unloading incidents

accounted for about 11 percent of the total cost impacts. 

Not surprisingly, the costs associated with injuries and fatalities from HM accidents accounted for about 80

percent of all impact costs for enroute accidents. For both release and non-release accidents combined, injuries

represented about 40 percent of the impact costs, and fatalities represented about 40 percent of all impact costs

for enroute accidents. Delays caused by traffic events for both release and non-release accidents added up to

about 9 percent of the total costs. Environmental damage, clean up, and evacuations accounted for the

remaining 3 percent of cost impact.

Non-Hazardous Materials Impacts/Costs

There were approximately 126,880 accidents for one year involving the transport of non-HM shipments and,

after compensating for under-reporting, approximately 109,779 injuries and 5,009 fatalities. Although primarily

due to a much larger volume of transport activity, the annual economic impact of non-HM accidents is over

$43 billion —considerably higher than for HM accidents. All but $7 billion of that cost resulted from injuries and

fatalities. 

Comparative Risks

All HM release and non-release accidents and incidents for transporting the various categories of HM shipments

averaged about $414,000 per event for one year. All non-HM accidents/incidents averaged about $340,000 per

event. Over a period of one year, the average cost per HM accident/incident with a release was about $536,000.

There is even greater contrast between the average cost impact of an HM release accident/incident resulting in

fire or explosion compared to the average cost of a non-HM accident/incident. 

The average cost of HM and non-HM motor carrier events are shown below in Table 2.

Accident Rate and Costs per Mile

The estimated number of annual accidents and incidents can be converted into rates by using annual vehicle

miles of HM operation. Based on estimated mileage from the 1997 Commodity Flow Survey (CFS), the accident

rate for transporting non-HM is 0.73 per million vehicle miles and is more than double the average HM accident

rate of 0.32 per million vehicle-miles. While the average cost for a single HM accident is higher than for a single

non-HM accident, the overall cost of non-HM accidents clearly dominates due to a large disparity in shipment

volume between HM and non-HM shipments. 

While mileage numbers provided a general measure of difference, more rigorous comparisons must await

further refinements in the accuracy of CFS mileage numbers.

Table 2

Average Costs of HM and Non-HM Motor Carrier Events

All HM Event $414,000 122% -----

HM Event with Fire $1.2 million 353% 8 hours

HM Event with Explosion $2.1 million 617% 12 hours

$340,000

TYPE OF EVENT AVERAGE

COST

PERCENTAGE

OF NON-HM

CRASH

AVERAGE

TRAFFIC

DELAY

Non-HM Event

HM Event w/ Spill Release $536,000

-----

158%

2 hours

5 hours
U.S. Department of Transportation

Researcher

This study was performed by

Battelle, 505 King Ave.

Columbus, OH 43201-2693.

Contract No. DTFH61-98-C-00060.

Distribution

This Tech Brief is being

distributed according to a

standard distribution. Direct

distribution is being made to the

Service Centers and Divisions. 

Availability

Phase one of the study’s final

report is available from the

National Technical Information

Service (PB99-150245).

Key Words

accident and incident delay,

hazardous materials, hazardous

materials classes, HM and nonHM accidents and incidents,

HMIS, impact costs, risk

assessment.

Notice

This Tech Brief is disseminated

under the sponsorship of the

Department of Transportation in

the interest of information

exchange. The Tech Brief

provides a synopsis of the

study's final publication. The

Tech Brief does not establish

policies or regulations, nor does

it imply USDOT endorsement of

the conclusions or

recommendations. The U.S.

Government assumes no liability

for its contents or their use.

Web Site

All FMCSA Tech and Analysis

Briefs may be accessed at:

http://www.fmcsa.dot.gov.

Technical Writer

Craig Steinberg

C2 Technologies, Inc.

July 2002

Publication No. FMCSA-RT-02-090

Conclusion and Findings

In conclusion, the findings of this study can be used to increase our understanding of the

key risk contributors of transporting HM and non-HM shipments. The results allow for risk

comparisons to be made between HM and non-HM shipments by establishing a general

dollar estimate of the financial impact, rather than a precise valuation. It is anticipated

that meaningful research and policy inferences can be derived for risk management

purposes. This report demonstrates the usefulness of a methodology for estimating the

number of accidents and incidents for a 1-year period.

Several findings were reported from the results of the study. The results suggest: 

• HM truck accidents and incidents cost society nearly $1.2 billion on an annual basis

• Injuries and fatalities make up the largest component of this cost

• Flammable and combustible liquids contribute the largest economic cost impact

associated with HM accidents and incidents

• Annual economic cost impacts of non-HM accidents is considerably higher than for HM

accidents due to the shear volume of their occurrences, even though the cost impact of

a single accident with an HM release is higher than a non-release HM accident

• Accidents with HM releases that result in explosions have the highest cost impact

followed by HM release accidents resulting in fires

Although public databases contain useful information for conducting risk assessments, they

are deficient in a number of areas that can be improved. The research study suggests that

better coordination efforts among the multiple agencies that collect transportation data

would correct data collection inconsistencies. Also, the collection of data should be done

in coordination with other datasets to enhance cross-referencing capabilities, which would

enable FMCSA to improve its safety performance monitoring abilities. The benefit of such

improvements would allow for the availability of information and a more economical way

of maintaining the databases—all of which can be used to help identify high-risk motor

carriers and improve the safety of transporting hazardous and non-hazardous materials.

Future Action

Applying the results of the risk assessment study to the SafeStat algorithm (an instrument

used to measure the safety fitness of motor carriers) is currently underway. Phase III of the

study analyzed the impact of HM on the carrier selection methodology and made

recommendations on the inclusion of hazardous materials risks, which are currently under

review by the FMCSA.

References

Comparative Risks of Hazardous Materials and Non-Hazardous Materials Truck Shipment

Accidents/Incidents, FMCSA, Washington, DC, March 2001. 

Hazardous Materials Risk Assessment: Phase I (Tech Brief), Federal Highway

Administration, Office of Motor Carrier Research and Standards,

Publication No. FHWA-MCRT-99-013, Washington, DC, June 1999.

Federal Motor Carrier Safety Administration