FEDERAL HIGHWAY ADMINISTRATION • OFFICE OF MOTOR CARRIER AND HIGHWAY SAFETY

FHWA Contacts: Joe DeLorenzo, HRC-MW, (708) 283-3572; Ken Rodgers, HMSA-10, (202) 366-4016 

Hazardous Materials Risk 

Assessment: Phase I

Introduction

The U.S. Department of Transportation (USDOT) strategic plan has recognized safety as

its most important strategic goal. The USDOT is committed to reducing the rate and

severity of transportation fatalities and injuries in hazardous materials (HM) transportation and to reducing the dollar loss from high-consequence transportation crashes.

This two-phase Hazardous Materials Risk Assessment project was designed to assist the

USDOT in achieving these strategic goals. The project will examine the total impact of

commercial vehicle transportation and determine what part of the total is a result of

HM transportation (by HM hazard class). The results will be used to evaluate the HM

program within the Federal Highway Administration, Office of Motor Carrier and

Highway Safety (OMCHS). It will also assist the agency with program development and

strategic planning. Included in this process will be an evaluation of the possibility of a

role for HM risk in the SafeStat algorithm, used as a selection tool for conducting 

compliance reviews. 

The completed Phase I characterized the shipment impacts for 1 year of Class 3 HM

shipments (flammable and combustible liquids). It also assessed the feasibility of conducting a comprehensive risk assessment of HM and non-HM shipments. Phase II will be

the actual comparative risk assessment between HM and non-HM truck shipments 

broken down by hazard class, as specified in the Code of Federal Regulations (49 CFR).

The Phase I portrait of HM crashes and incidents focused on estimating the impacts of 

1 year of HM transportation for Class 3 HM materials. Class 3 materials were selected

because of their relative importance among HM shipments in terms of shipment 

volume and their potential for causing injuries and damages during a crash; 52 percent

of HM shipments are Class 3 materials. This tech brief summarizes the 1-year portrait 

of HM crashes/incidents and their impacts. For this discussion, an incident is an event in

which HM is unintentionally released from a package (49 CFR171.16).

Purpose

The main purpose of Phase I of this project was to develop a methodology for predicting consequences of HM crashes, such as injuries and property damage. An initial step

in developing a risk assessment is to reliably estimate the number of crashes and 

incidents for a defined period of time. The report documented a process to evaluate

the full impact of HM crashes and incidents by sampling a single HM class for 1 year. 

Methodology

Estimating Crashes and Incidents

For this phase of the project, an estimate of crashes and incidents was developed for

Class 3 HM truck shipments in 1996. The estimate used the Hazardous Materials

Information System (HMIS), as the baseline database, and supplemented this 

Tech Brief

The mission of the Office of

Motor Carrier and Highway

Safety is to develop and 

promote, in coordination with

other Departmental modes,

data-driven, analysis-based,

and innovative programs to

achieve continuous safety

improvements in the Nation’s

highway system, intermodal

connections, and motor carrier

operations. The Office of

Motor Carrier Research and

Standards manages the safety

regulatory program and the

central research management

function for Motor Carrier and

Highway Safety.

There are eight major research

and technology focus areas:

regulatory evaluation and

reform; compliance and

enforcement; driver training

and performance management; driver alertness and

fatigue; driver physical 

qualifications; car-truck 

proximity; HAZMAT safety 

and cargo tank integrity; and

crash causation and profiling.

HAZMAT safety and cargo

tank integrity concentrates 

on assessments of HAZMAT 

safety issues, in particular 

the roll stability and crashworthiness of cargo tanks.

Office of Motor Carrier Research

and Standards

400 Seventh Street, SW

HMCS-30; Room 3107

Washington, DC 20590
information with several other sources of data to

adjust the incidents and crashes reported in the HMIS

to more realistically reflect their actual number in a 1-

year period. For the purposes of OMCHS’s risk assessment study, the HMIS represents the only national

database of HM highway transportation 

incidents with details of the material, packaging, and

consequences involved. 

To effectively supplement the HMIS data, researchers

selected a sample of eight States on which to focus

for a more intensive examination, which included six

PRISM (Performance and Registration Information

Systems Management) States: Colorado, Indiana,

Iowa, Minnesota, Pennsylvania, and Oregon. The

PRISM States were chosen because of their focus on

improved data quality. In addition, California and

Ohio were chosen because of state data sources that

were valuable to the study. The HMIS data for these

eight States were compared with respect to specific

crashes found in one or more of the additional 

databases, identifying a portion of under-reported

crashes. 

The search criteria used to identify the 1996 Class 3

HM truck shipments for each database included the

following:

• Year = 1996 

• Crash (or Incident)

• HM Class = 3

• Placarded Vehicle

• Enroute (traveling from origin to destination) 

The study includes both HM crashes (no-spill events)

and HM crashes with a release, in addition to 

incident-only scenarios (loading, unloading, and other

spill events with no associated crash). This will allow

OMCHS to consider whether even with no spill, HM

crashes result in higher consequences than non-HM

crashes. After analyzing the data in various databases,

the crash count for the eight case-study States was

used as a measure to calculate the number of crashes

for the nation. The process required four steps: 

1. The number of crashes for the eight States was

estimated by supplementing the HMIS data with

information from other databases. 

2. A proportion of the national crashes represented

by the eight States was calculated. Commodity

flow and truck registration data were used to 

estimate the portion of the total national HM 

traffic represented by the eight States. The total

commodity ton-miles of HM transport within the

eight States represents about 30 percent of the

total ton-miles for the United States. 

3. The crash estimates for each of the eight States

were totaled. 

4. The total estimated national crash number was 

calculated by assuming the additional 70 percent

of the national crashes occurred at the same rates

and types and then by adding the estimate for the

remaining 42 States to the 8-State estimate.

Researchers estimated incidents in a more direct 

manner. Because the HMIS is the best source for

enroute and loading/unloading incidents, HMIS 

data were used for all 50 States. 

Impact Methodology

In order to derive an estimate of annual economic

impact of crashes/incidents involving shipments of

Class 3 HM, a number of consequences must be taken

into consideration. Impact categories were selected

that could be compared among the crashes/incidents.

These consequences go beyond the traditional 

consequences studied when dealing with transportation-related crashes and incidents. This was done to

develop a more comprehensive picture of the impacts

and cost of HM transportation for society. 

• Injuries and deaths

• Cleanup costs

• Property damage

• Evacuation

• Product loss

• Traffic incident delay

• Environmental damage

Several sources of information were reviewed to

establish reasonable estimates of the economic

impact of each consequence. Researchers conducted a

comprehensive literature review to identify unit costs

that have been used in prior economic evaluation

studies related to transportation, environmental

health, and safety. 

Researchers then tallied the impacts reported in 

federal and state databases; these were supplemented with information about impacts derived 

from literature sources and through interviews with

knowledgeable sources. Impact numbers not readily

available from these sources were modeled in order

to develop impact estimates. All impacts were 

converted to dollar values to enable comparison

among the impacts and derive a total impact figure

for the sample year of 1996. 

Impact Figure Estimates

The HMIS was an important source of impact costs 

for product loss, cleanup costs, and property damage.

Injuries and deaths were valued at the amount the
USDOT would spend to avoid the injury or fatality.

These monies can be equated with the costs associated with enhanced safety measures (e.g.,regulatory

safety programs, design standards, vehicle occupant

crash protection) designed to prevent transportationrelated fatalities. This averaged $200,000 for crash

injuries and $2,000,000 for a fatality. Some portions

of the USDOT already use this estimate to assess the

cost of avoiding a serious injury or fatality. 

Traffic incident delay was established as the total

number of people delayed at an incident or crash

multiplied by $15 per hour, which takes into account

the value of a driver’s time and fuel consumption

costs. In earlier studies (Grenzeback L.R., et al., 1990),

average unit vehicle cost was calculated from a unit

cost per vehicle hour of $10.92 (1990 dollars) from the

Highway Economic Requirements System. The figure

was then adjusted to 1998 dollars. Environmental

damage was estimated based on the size of an 

average spill and the value placed on environmental

contamination as determined by an average of 30 

settlements. Table 1 provides an example of a specific

impact case for a Class 3 HM accident.

Findings

For 1996, the impact in terms of dollars for the estimated Class 3 crashes and incidents was approximately $482,000,000. Injuries and fatalities accounted for

about 69 percent of the total cost. Carrier damage

and incident delay costs together accounted for

about 25 percent of the total estimated cost. 

The cost related to HM crashes is considerably higher

than that for incidents. Table 2 shows a breakdown of

the costs of HM crashes indicated by Phase 1 of this

study as compared to those indicated by HMIS. This

study has developed a more comprehensive assessment of the costs associated with HM crashes and

incidents. 

No-spill crashes account for 58 percent of the 

estimated costs; this is primarily because there are

almost twice as many no-spill crashes as spill crashes.

There are no cleanup costs included in the product or

environmental damage costs; however, no-spill 

crashes led to considerably more injuries and slightly

more fatalities than spill crashes. 

Table 1. 

Impact Case Example.

October 29, 1996, 4:50 a.m., near Kirkersville, OH. A tanker truck, traveling eastbound on I-70, went 

into the median and rolled onto its side. The cargo tank was carrying 6,800 gallons of acetone. Less than 

100 gallons of the hazardous cargo were released through the tank’s pressure relief valve. The driver was

taken to the hospital with injuries. Both the eastbound and westbound lanes of I-70 were closed at 5 a.m.,

and were expected to open by 2 p.m. An environmental contractor was called to clean up the spill.

Field Value

HM Information Commodity Acetone

Class 3; Flammable - Combustible Liquid

Quantity Spilled Less than 100 gallons

Accident Information Location I-70 eastbound, near Kirkersville, OH 

(Rural community)

Fatalities 0

Injuries 1 person, $400,000

Evacuation 0

Damages Product Loss $500

Carrier Damage $2,000

Public/Private property damage $0

Decontamination/cleanup $1,500

Incident Delay $83,025

Environmental Damage $88

Total Estimated Cost $487,113
Researcher

This study was performed by

Battelle, 505 King Avenue,

Columbus, Ohio 43201.

Contract No. DTFH61-98-C00060.

Distribution

This Tech Brief is being 

distributed according to a 

standard distribution. Direct 

distribution is being made to

the Resource Centers and

Divisions.

Availability

The study final report will be

available from the National

Technical Information Service,

Telephone: (703) 605-6000.

Key Words

hazardous materials, risk 

assessment, incident, hazardous

materials incident, Hazardous

Materials Information System.

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

FHWA endorsement of the conclusions or recommendations.

The U.S. Government assumes

no liability for its contents or

their use.

Impact estimates related to the fact that the cargo is HM are important for both the

current analysis and any future risk assessments or modeling. An analysis of the crash

and incident impacts determined which impacts were the result of the HM cargo being

shipped. About $122,800,000 of the $459,000,000 in impact costs from HM crashes can

be directly related to the hazardous nature of the cargo. This represents about 30 

percent of the impact costs for the major Class 3 crashes and incidents estimated for

1996. 

Conclusions and Future Research

This study demonstrated a process to evaluate the full impacts of HM crashes/incidents

by sampling a single HM class for one year. By characterizing the shipment impacts for

1 year of Class 3 HM shipments the study demonstrates a process that can be applied to

determining the impacts of other HM classes as well as for non-HM shipments. 

Specifically, the study has demonstrated the feasibility of obtaining data and conducting analysis in the following areas: 

• Estimation of the number of crashes and incidents for 1 year. 

• Estimation of the type and magnitude of impacts from crashes and incidents.

• Identification of data needed for the full risk assessment.

The report provides a solid beginning for the comparative risk assessment scheduled

for the second phase of this study which is scheduled for completion in fiscal year 2000. 

Reference

Grenzeback, Lance R., et al., “Urban Freeway Gridlock Study: Decreasing the Effects of

Large Trucks on Peak-Period Urban Freeway Congestion,” Transportation Research

Record, No. 1256, 1990.

June 1999

Publication No. FHWA-MCRT-99-013

Table 2. 

Comparison of 1996 HMIS Transportation Crash Impact Estimates and

Phase I Comprehensive Crash Impact Estimates, Class 3 HM Shipments.

Impact HMIS Phase I Comprehensive

Cleanup $6,552,972 $16,660,000

Product Loss $547,789 $1,862,000

Carrier Damage $6,155,936 $51,948,000

Property Damage $1,572,115 $8,513,700

Environmental Damage N/A $882,000

Injury $3,000,000 $190,600,000

Fatality $6,000,000 $134,000,000

Evacuation $647,000 $1,950,000

Incident Delay N/A $52,874,357

Total Costs $24,475,812 $459,290,057