“...a good plan addresses specific actions and assigns timeframes. It need not be overly 

detailed, but should be sufficient to communicate what needs to be done, in what order, 

and what issues will need addressing in completing each task. A good plan will 

recognize and respect the make-up of the organization and other known priorities. It 

will be ambitious but not overly so. Implementation plans should consider basic areas 

such as training, organizational issues, agency policies, data management, and 

information technology.”

- FHWA’s HSM Implementation Guide for Managers

Highway Safety Manual Case Study 5: 

HSM Implementation Plans – New Hampshire DOT 

Experience

HSM Reference

The American Association of State Highway and Transportation Officials’ (AASHTO) Highway 

Safety Manual (HSM), published in 2010, provides access to the latest science-based knowledge 

on the proven relationship between crashes and the roadway environment, thus enabling the 

safety effects of actions or treatments involving the highway and street environment to be 

quantified.

The HSM provides roadway agencies with access to meaningful quantitative safety measures 

that can inform project decisions and therefore improve the understanding of tradeoffs 

involving other aspects, such as environmental concerns, rights-of-way, and stakeholder issues. 

The application of these quantitative measures can demonstrate and prove over time the direct 

and meaningful return for investments in safety to the stakeholders and improve confidence 

that safety funds are being applied most effectively.

The HSM is organized in four parts: Part A – Introduction Human Factors, and Fundamentals 

of Safety; Part B – Roadway Safety Management Process; Part C – Predictive Methods; and Part 

D – Crash Modification Factors (CMF). The HSM is a potentially transformative resource for 

departments of transportation (DOT) and other agencies responsible for planning, design, 

construction, and operation of highway systems.

Description

The HSM represents a change in the formalized decision-making process for a DOT. Therefore, 

it is important that states develop and follow effective implementation plans before attempting 

to adopt the HSM. An HSM implementation plan should reflect the specific attributes, culture, 

and capabilities of the user organization. Furthermore, an understanding of the agency’s 

organization and identification of influential decision-makers, potential champions within each 

office, and what is reasonably achievable over time given the agency’s other priorities can all

influence the makeup of an implementation plan.

Vision. An effective implementation plan should lay out a roadmap that clearly defines the 

vision for how the HSM, over time, can influence the way in which safety is considered in all 

decisions and is incorporated into the agency’s overall project development process. The 

roadmap should include a timeline that focuses on where early successes are most likely to be 
HSM Implementation Plans Case Study: NHDOT Experience

2

achieved so that benefits are demonstrated and confidence is gained.

The New Hampshire DOT (NHDOT) developed a roadmap of the State’s current HSM 

integration status and implementation strategy for a regionwide implementation. The roadmap 

highlights the activities initiated before the release of the HSM, current efforts, and upcoming 

activities. NHDOT also developed an implementation plan that was approved by executive 

leadership. To effectively pursue the implementation plan, they formed an implementation 

team, comprising representatives from traffic, highway design, planning, and safety bureaus, 

cities, and Regional Planning Commissions that have partnered with FHWA and the Maine and 

Vermont DOTs.

Dissemination of Training. Implementation plans should address how the agencies will 

disseminate the HSM and conduct training across their agency and partners. Agencies are

encouraged to identify and establish a method for integration of the HSM, including the HSM 

supporting software if needed. Training needs to be planned strategically; for example, not 

everyone needs to be trained at once or have the same in-depth knowledge. Customizing 

different training sessions for key personnel within the agency should be considered, as well as 

encouraging senior leadership to participate.

The NHDOT HSM implementation included training 

initiatives both before and after release of the HSM. The first 

two training phases, prior to the release of the HSM, targeted 

audiences included executive leadership, bureau 

administrators, and traffic operations, planning, and highway 

design managers. Such efforts helped build the path and 

prepare personnel by providing them with fundamentals of 

highway safety. For the third training phase, after the release 

of the manual, the target audience ranged from executive 

leadership to safety analysts. This phase also included training 

on IHSDM and SafetyAnalyst, as they have adopted AASHTOWare SafetyAnalyst software for 

Network Analysis, and have been using IHSDM on a select number of projects. Results from 

these tools are being used in the economic decision-making process. The implementation plan 

includes future training for locals, consultants, and Regional Planning Councils in the New 

Hampshire, Vermont, and Maine areas. Additionally, employees of the DOT have been taking 

advantage of the HSM recorded sessions from the HSM web site.

Skills Assessment. Agencies also will need to assess the availability and quality of skills within 

their agency to conduct the more-sophisticated analyses provided in the HSM. To obtain the 

full benefit of the HSM, skills relating to statistical modeling and experimental design are 

important. Such skills are needed to calibrate the HSM predictive models and/or develop 

agency-specific Safety Performance Functions (SPF) and perform project evaluations.

While NHDOT Safety staff has a background in Generalized Linear Models (GLM) they have 

not developed state specific SPFs or CMFs. They are working to improve the overall quality of 

the state data set before investing time and effort in their development. In the interim the State 

is using calibrated SPFs and published CMFs. 

Policies. Revisions to agency policies will require coordination across internal offices to ensure 

HSM is integrated into the project development process. An implementation plan should 

NHDOT Implementation 

Plan Components:

- Marketing/Outreach

- Implementation Team

- Training

- Support Materials

- Policy and Guidance

- Support
HSM Implementation Plans Case Study: NHDOT Experience

3

include an evaluation of project development and design manuals containing safety 

information or processes. Careful consideration must be given to the agency’s decisions and 

investments in SPF development and/or calibration factors development and Highway Safety 

Improvement Program (HSIP) activities, including current data and analysis tools.

As part of the HSM implementation, NHDOT is targeting their Strategic Highway Safety Plan, 

transparency report, corridor studies, and project evaluations, among others, as focus areas for 

incremental implementation of HSM methods.

Data. It is also essential to have a good understanding of the data quality needed to support 

HSM analyses. The implementation plan should include a data assessment and identify

additional data collection efforts to address existing data gaps. These may include missing

traffic volume data or roadway inventory data, for example.

With the objective of addressing data gaps and improving its data systems, NHDOT is currently 

participating in FHWA’s Model Inventory of Roadway Elements Management Information 

System (MIRE MIS) Lead Agency Program, as well as a CMF Study. After the MIRE MIS 

program is completed, NHDOT is expecting to have a more robust data system, thereby 

allowing the agency to develop its own SPFs. In addition, NHDOT has projects and initiatives 

targeting improvements in safety data, including crashes, horizontal curves, traffic, 

intersections, ramps, and other roadway elements. They have a video log database of the state 

system that is updated every two years. This information along with aerial mapping and GIS 

data is used for data collection.

Benefits

By developing an implementation plan to guide initial HSM efforts agencies can make better 

assessments of the needs and resources required to advance safety analysis in all project 

development processes. An HSM implementation plan can also identify the full potential that

HSM can provide to the entire organization. 

An HSM implementation plan allows for strategic planning and management of an integration 

and implementation effort. In addition to planning obvious tasks such as training or database

development and management; implementation plans guide agencies as they examine their 

internal program and project development policies and risk management procedures. Agencies 

can better anticipate the internal engagement needs of their project delivery staff to achieve the 

greatest benefits for the agency and its customers.

Contact

Stuart Thompson

State Highway Safety Engineer

New Hampshire Department of 

Transportation

(603) 247-3549

GThompson@dot.state.nh.us

“Our leadership continues to support and 

encourage the develop and implementation of 

the HSM as a tool to help meet our

commitment of providing the safest roads 

possible” – Stuart Thompson, NHDOT