NEW HAMPSHIRE DEPARTMENT OF 

TRANSPORTATION SAFETY DATA 

SYSTEMS AND PROCESSES 

CASE STUDY

FHWA-SA-15-058

Prepared for

Federal Highway Administration

Office of Safety

November 23, 2015
NEW HAMPSHIRE DOT CASE STUDY

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NEW HAMPSHIRE DOT CASE STUDY

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Notice

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NEW HAMPSHIRE DOT CASE STUDY

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ACKNOWLEDGEMENTS 

The FHWA Office of Safety Data Management Systems and Processes Project team would like 

to thank the following individuals who graciously provided information needed to develop this 

case study.

Name Title Department Email/Phone#

Timothy (Tim) 

Harmon 

Assistant Highway 

Safety Engineer 

New Hampshire 

Department of 

Transportation 

tharmon@dot.state.nh.us 

(603) 271-2171 

Glenn Davison GIS Project Manager 

in Planning

New Hampshire 

Department of 

Transportation 

gdavison@dot.state.nh.us 

(603) 271-7145 

James (Jim) 

Marshall 

Administrator, 

Highway Design

New Hampshire 

Department of 

Transportation 

jamarshall@dot.state.nh.us 

(603) 271-2171 

William (Bill) 

Oldenburg 

Assistant Director of 

Project Development

New Hampshire 

Department of 

Transportation 

woldenburg@dot.state.nh.us 

(603) 271-2171 

Michelle 

Marshall 

Highway Safety 

Engineer 

New Hampshire 

Department of 

Transportation 

MEMarshall@dot.state.nh.us 

(603) 271 - 2171 

Nicholas (Nick) 

Alexander 

Asset Management, 

Performance, and 

Strategy (AMPS)

Manager 

New Hampshire 

Department of 

Transportation 

nalexander@dot.state.nh.us 

(603) 271 - 8457 

Martin (Marty) 

Calawa

Safety Engineer FHWA New 

Hampshire Division Martin.calawa@dot.gov 

(603) 410-4864 
NEW HAMPSHIRE DOT CASE STUDY

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ACRONYMS

Acronym Description

AASHTO American Association of State Highway and Transportation Officials 

DOT Department of Transportation

FHWA Federal Highway Administration

GIS Geographic Information System

HSM Highway Safety Manual

IT Information Technology

LRS Linear Referencing System

MIRE Model Inventory of Roadway Elements

NCHRP National Cooperative Highway Research Program

NHDOS New Hampshire Department of Safety

NHDOT New Hampshire Department of Transportation 
NEW HAMPSHIRE DOT CASE STUDY

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TABLE OF CONTENTS

ACKNOWLEDGEMENTS ...........................................................................II

ACRONYMS................................................................................................. III

TABLE OF CONTENTS............................................................................ IV

INTRODUCTION......................................................................................... 1

NHDOT TECHNOLOGY AND SAFETY DATA MANAGEMENT ....... 3

Analytical Tools .......................................................................................................... 3

Integration Tools ........................................................................................................ 3

Data Sharing Tools ..................................................................................................... 4

NHDOT TECHNOLOGY AND DATA GOVERNANCE ........................ 6

APPLICABILITY TO OTHER STATES..................................................... 8

RESOURCES ............................................................................................... 10

REFERENCES .............................................................................................. 11
NEW HAMPSHIRE DOT CASE STUDY

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LIST OF FIGURES

Figure 1. New Hampshire DOT Interactive Map........................................................... 5
NEW HAMPSHIRE DOT CASE STUDY

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INTRODUCTION

The purpose of this case study is to highlight noteworthy practices of the New Hampshire 

Department of Transportation (NHDOT) in leveraging technology to enhance safety data 

management—in particular, NHDOT’s use of an integrated Linear Referencing System (LRS)

and use of information technology (IT) tools to analyze safety data (e.g., AASHTOWare Safety

AnalystTM, American Association of State and Highway Officials (AASHTO) Highway Safety 

Manual (HSM), and Graphical Information Systems (GIS) tools). New Hampshire’s use of 

technology improves management of safety data systems by providing mechanisms for: 

• Electronic data collection, thereby reducing data errors at the point of collection; 

• Integration of data from different systems, using GIS and a consolidated LRS; 

• Access to multiple types of safety data through a single portal that extracts and displays 

crash, traffic, and road inventory data; and

• Analysis of data for identification of high crash “hot spots,” or locations with potential 

for safety improvement, using safety performance functions to estimate expected crash 

frequency of all sites across the road network. 

NHDOT uses an integrated LRS which provides a common link between safety data sets, 

including crash, traffic, and road inventory data. Their use of GIS applications helps to improve 

overall data quality by providing a method for visualization of data on maps and identification of 

data errors for correction, prior to their potential use with analytical tools. NHDOT’s use of 

analytical tools, such as AASHTOWare Safety AnalystTM and the AASHTO HSM, promotes data 

quality by requiring data formatted in a certain way, according to specific data standards, and 

within defined levels of accuracy in order for the analytical tools to work properly. Many 

States, including New Hampshire, are also working to improve the quality of the data 

recommended within the Model Inventory of Roadway Elements (MIRE). For NHDOT, 

improving the quality of data following MIRE recommendations is important, and they plan their

data collection scope and methods accordingly. They prioritize their efforts toward meeting

recommended minimum conditions by concentrating on the intended use of data and the way it 

supports analysis tools. 

One of the prominent research projects recently completed pertaining to the topic of 

enhancing data management and data governance practices is NCHRP 666: Target-Setting 

Methods and Data Management to Support Performance-Based Resource Allocation by Transportation 

Agencies (2010). NCHRP 666 provides systematic guidance for establishing data management 
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(and data governance) programs within an organization. The following six steps from NCHRP 

666 have been adapted for safety data programs:

1

1. Establishing a need for safety data management and governance

2. Establishing goals for safety data management

3. Assessing the current state of safety data program systems

4. Establishing safety data governance programs

5. Leverage technology for safety data management

6. Linking safety data to planning, performance measures, and target processes

One of the key steps (outlined below) is the necessity to leverage technology to support data 

management practices, which is the primary focus of this case study.

This case study focuses on how New Hampshire has leveraged technology for safety data 

management through analytical, integration, and data sharing tools as well as through standards 

set forth as part of their data governance efforts. 

 

1 NCHRP Report 666: Target-Setting Methods and Data Management to Support Performance-Based Resource 

Allocation by Transportation Agencies (2010), http://onlinepubs.trb.org/onlinepubs/nchrp/nchrp_rpt_666.pdf. 
NEW HAMPSHIRE DOT CASE STUDY

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NHDOT TECHNOLOGY AND SAFETY DATA MANAGEMENT

NHDOT’s use of technology for safety data management focuses on their use of an integrated 

LRS and the use of analytical tools, including the HSM and AASHTOWare Safety AnalystTM. 

Each analytical tool requires data defined and formatted in a particular way. The Department 

has invested resources in the collection of ramp and intersections data elements to provide 

more analytical capabilities for their safety program. NHDOT made the decision to focus on 

improving the quality of their data prior to establishing formal data management policies, 

standards, and procedures within a data business plan framework. Ultimately, improving data 

quality will improve decision-making, especially with the use of analytical tools to support their

safety program. 

Analytical Tools

NHDOT’s experience includes the use of safety analytical tools (including the HSM and 

AASHTOWare Safety AnalystTM) to support their safety programs. NHDOT uses their safety 

datasets to calibrate Safety Performance Functions (SPF) in AASHTOWare Safety AnalystTM to 

local conditions. At NHDOT, the use ofsoftware-based analytical tools such as Safety 

AnalystTM, the Interactive Highway Safety Design Model, safety analysis spreadsheets, and 

internally developed software necessitates a thorough review of data elements, requires the 

safety group collaboration with IT, and helps demonstrate a need for institutionalizing methods

outlined in the HSM. 

Integration Tools

NHDOT’s data integration efforts began around 2005 and they are now able to provide access

to multiple data sets using a single platform through their LRS. Offices at NHDOT collaborated

with the New Hampshire Department of Information Technology to demonstrate the benefits 

of using a common GIS and LRS platform (e.g., access to multiple data sets through use of an 

integrated LRS platform), which resulted in strong support for continued maintenance of the 

system. 

Part of development and management of the LRS at NHDOT is ensuring it includes all public 

roads and associated data needed for safety analysis and decision-making. Using GIS tools and a 

common LRS, NHDOT works directly with local communities each year to keep all available 

road network data complete, accurate, and current in one official state road network. In 

addition, NHDOT uses the LRS to link crash data to the official road network by verifying and 

relating crash locations derived from records maintained by the New Hampshire Department 
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of Safety (NHDOS), the official repository of all crash records. The NHDOT works closely 

with the NHDOS to verify locations to relate crash data to the road network. The result of 

this cross-department collaboration is accurate and reliable crash data integrated with other 

data linked to the official road network such as traffic volumes and roadway elements. This 

integration benefits a number of tools and applications used to support safety analysis and 

decision-making. 

At NHDOT, the Transportation Systems Management group in the Bureau of Planning and 

Community Assistance are the data stewards for the LRS. They continue to work to integrate 

data sets from multiple business areas, while demonstrating how the LRS can provide access to 

the multiple types of data that support business area needs, especially those related to the 

safety program. The LRS supports the safety program by providing consistent location data for 

integrating essential datasets for safety analysis purposes. Use of the LRS requires following 

specific business rules, data standards, and procedures for management of the data. 

Participation is also required from many offices that have responsibility for maintaining the 

different data layers such as bridge, traffic, crash, and pavement data. The LRS encourages 

multiple users to contribute to the maintenance of their data layer by rewarding them with 

access to other data layers in the integrated system for use in their business areas. 

NHDOT’s use of the LRS extends to data visualization on interactive web maps (Figure 1). 

This ability helps to improve data quality by providing a means for safety analysts to investigate

areas where there is missing data or where data values appear to be out of anticipated ranges. 

For instance, greater than expected traffic volumes may appear as heavier lines or as a different 

color compared to lower traffic volumes or missing traffic data might appear as gaps in line 

segments on the map. 

Data Sharing Tools

NHDOT uses data sharing technology to provide data to a wider audience. Sharing data 

maximizes the potential to locate and correct errors reported by the data reviewers, which 

ultimately leads to improved data quality. Since NHDOT’s safety programs rely on the ability 

to access crash data collected by the NHDOS, investments in data sharing technology are

critical for sustaining and enhancing NHDOT’s safety program. The current method to transfer 

crash data from the NHDOS to NHDOT is through text files. However, plans are underway 

to update this method to allow access to the data within a relational database environment. 

NHDOT also shares data using a variety of methods to meet different user needs. These 

methods include providing quarterly snapshots of GIS data to regional planning agencies, 

providing GIS data to an online statewide GIS warehouse called GRANIT (which stands for 
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Geographically Referenced Analysis and Information Transfer System), and providing GIS web 

maps maintained by NHDOT that are publicly available online (Figure 1). 

Figure 1. New Hampshire DOT Interactive Map

Source: NHDOT GIS Data Catalog
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NHDOT TECHNOLOGY AND DATA GOVERNANCE

NHDOT is focusing on improving the quality of their safety data and other key data sets as part 

of the current data management strategy. The safety program data managers utilize all available

sources of data definitions and data structures, like those defined for MIRE and Model Minimum 

Uniform Crash Criteria Guideline, to improve the quality of data sets used with AASHTOWare 

Safety AnalystTM and the Highway Safety Manual. 

NHDOT’s current focus on improving data quality and their use of information technology 

tools provides the building blocks of data governance for the safety program. Establishing a 

successful data governance program for safety begins with defining goals for the program. 

NHDOT’s 2012-2016 Strategic Highway Safety Plan identifies three goals specified for safety 

data improvement: 

1) Improve collection and submission of crash reports by implementing electronic 

reporting 

2) Improve road inventory data by adopting MIRE 

3) Evaluate the current state system and needs for improvement 

These goals drive the initiatives at NHDOT for improving access to and use of safety-related 

data sets to support the Strategic Highway Safety Plan, as well as the Highway Safety 

Improvement Program and other program areas that support safety initiatives. 

Although NHDOT does not have a formal safety data business plan in place, because of their 

success in effectively managing data and implementing safety analysis tools, they are in an ideal 

position to take the next steps by defining a mission statement and identifying roles and 

responsibilities for the management of their safety data sets. Getting to the stage they are in 

now has taken coordination and collaboration between business areas and IT professionals, and 

wouldn’t be functional without some informal data governance structure. 

At NHDOT, safety project identification and prioritization processes use performance-based 

criteria through one or more methods, including: 

• Network screening - ranks sites by Potential for Safety Improvement (PSI), either in all 

crashes or a specific type of crash. 

• Road Safety Audits - typically locally or politically requested safety audits at sites with noted 

safety concerns. 
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• Systemic approach - wide implementation of low unit-cost countermeasures at sites with 

high potential for improvement or demonstrated risk factors.

• Systematic improvement projects - wide implementation of research proven safety 

countermeasures.. These projects typically include certain processes, infrastructure design 

techniques, and highway features. 

Based on the importance of performance-based criteria for prioritization of safety projects, 

NHDOT could tie the process to data business planning by developing and adopting mission 

statement(s) and a list of responsibilities for the safety program similar to that adopted for the

pavement management program. 

While NHDOT does not currently have a safety data business plan implemented, the 

commitment to the use of information technology tools for safety data analysis and continued 

emphasis on improving data quality of safety-related data sets, combined with the spirit of 

cooperation among different business areas at the Department, provides the perfect foundation 

for future expansion of data governance and data business planning to support the Safety 

Program at NHDOT.
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APPLICABILITY TO OTHER STATES

New Hampshire DOT’s experience demonstrates the importance of leveraging IT to support 

safety programs at State DOTs. All business areas rely heavily on an IT infrastructure to store, 

process and manage large data sets within multiple platforms. The challenges associated with 

this dependency (business needs and IT hardware/software) can sometimes be overwhelming. 

However, new technologies are available to assist in this effort and they are useful in improving 

data quality and improving data sharing to support the safety program. 

Many of NHDOT’s experiences in the use of information technology are readily transferable to 

other State DOTs. These experiences can serve as a checklist and reminder to States of what 

works well (e.g., benefits derived) with regard to utilizing technology. The benefits include the 

ability to demonstrate how continued improvements in information technology provide a

return on investment for funding of IT initiatives. Listed below is a summary of some of 

NHDOT’s experiences in using technology to improve safety data. These experiences are 

similarly applicable at other State DOTs. 

• State DOT business areas, including safety program managers, should reach out to their 

partners in the IT offices to remain informed on the technology that is available (or 

recommended) to support various business operations. This approach provides an 

incentive for safety managers to solicit support from the IT office in designing application 

systems or procuring hardware and software products that best suit the needs of the Safety 

Program. 

• It is beneficial to have people in the Safety office who understand technology or, at a 

minimum, have working relationships with people who do, for the purposes of obtaining 

advice on how IT products can improve access to, integration of, and sharing of data sets 

used for the Safety Program. 

• Safety program managers should stay informed on what others are doing in the department 

regarding data collection and management of data sets that currently or potentially could be 

useful for the Safety Program. In addition, it is important to prioritize data collection efforts 

to focus on required data elements over optional ones. 

• Collect data that works with the technology used. This requires an understanding of the 

capabilities offered by vendor data analysis products and an understanding (that can be
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provided by IT staff) of how the products may be integrated for use to support the safety 

program. 

• Think long-term about how technology fits into an overall safety data management/safety 

data governance strategy. The safety program area primarily consumes data from other 

business areas, so technology that provides integration and sharing of data across business 

areas is critical for meeting the needs of the safety program and for supporting safety data 

governance. 

• Determine what data is required for the type of analysis performed for the Safety Program, 

and focus on data and analytical tools needed to support that analysis.

• Start with the LRS as the foundation and integrate safety-related data sets that can be 

associated with the LRS, and then improve the data over time.

• Coordinate data collection efforts with other agencies (including local agencies) to expand

the pool of data available for the safety program. 
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RESOURCES

The source of funding for the various safety data management and information technology 

initiatives at NHDOT depends upon the initiative.

State Planning and Research (SPR) funds are used to maintain the GIS and LRS data; Highway 

Safety Improvement Program funds are used to support safety data collection, to procure 

licenses for AASHTOWare Safety AnalystTM, and for other analytical tools; and the National 

Highway Transportation Safety Administration 405 grants are used to develop the electronic 

crash reporting system and to collect and maintain the crash records database. 
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REFERENCES 

The following sources aided in developing this case study.

• Phone interviews and email conversations with: 

− Martin (Marty) Calawa, Safety Engineer, FHWA New Hampshire Division

− Glenn Davison, Planning, GIS Manager, NHDOT

− William (Bill) Oldenburg, Assistant Director of Project Development, NHDOT

− Michelle Marshall, Highway Safety Engineer, NHDOT

− Timothy (Tim) Harmon, Assistant Highway Safety Engineer, NHDOT

− Nicholas (Nick) Alexander, Asset Management, Performance, and Strategy (AMPS) 

Manager, NHDOT

• NCHRP Report 666: Target-Setting Methods and Data Management to Support 

Performance-Based Resource Allocation by Transportation Agencies (2010), 

http://onlinepubs.trb.org/onlinepubs/nchrp/nchrp_rpt_666.pdf. 

• Calibration of the Highway Safety Manual for Missouri, (Final Report Date: December, 

2013), http://library.modot.mo.gov/rdt/reports/tr201302/cmr14-007_reduced.pdf. 
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Anita Vandervalk, Dena Snyder, Kim Hajek, Talena Adams, and Lisa Smith from Cambridge 

Systematics, Inc. contributed to this project.

FHWA, Office of Safety 

Stuart Thompson, P.E. 

Federal Highway Administration 

202-366-8090 

Stuart.Thompson@dot.gov

http://safety.fhwa.dot.gov/rsdp/