THE HIGHWAY SAFETY IMPROVEMENT PROGRAM (HSIP) 2021

1 FHWA, “Data-Driven Safety Analysis (DDSA),” Roadway Safety Data Program, https://safety.fhwa.dot.gov/rsdp/ddsa.aspx.

HSIP in 2021

Data collection projects had an 

AVERAGE COST OF 

$700,000.

Data analysis projects had an 

AVERAGE COST OF 

$200,000.

7%OF DATA-RELATED 

PROJECTS WERE 

ROAD SAFETY AUDITS.

140 

DATA-RELATED 

PROJECTS.

HSIP 

funded

WHAT TYPES OF DATA 

DID PROJECTS USE?

1%

19% Fatal Crashes Only Other Data Types

28%

Fatal and Serious 

Injury Crashes Only

52%

All Crashes

This information comes from 2021 State HSIP reports. To view individual reports, visit https://safety.fhwa.dot.gov/hsip/reports/.

WHAT PROGRAM METHODOLOGIES 

DID PROJECTS USE?

9%

Relative Severity Index

8%

Specific Crash Type Probability

8%

Specific Crash Types Overrepresented

28%

Crash Frequency

15% 

Other Data

Using Data to Drive HSIP Investments

In 2021

States obligated 

$48 million in HSIP 

funds to data-related 

projects.

A Safe System Starts with Quality Data

The first step to a safer roadway system is good data. The traditional approach to 

addressing traffic safety identifies safety issues after crashes occur. Using quality 

data to identify and mitigate contributing circumstances can reduce crash severity 

and help prevent future crashes. Quality data provides transportation professionals 

a means to make better decisions, select more strategic investments, and 

improve overall network safety. Two types of data-driven safety analysis help 

transportation agencies quantify safety impacts and identify high-risk roadways:

1. Predictive Analysis—Practitioners and the public make decisions 

based on a roadway’s projected safety performance using 

crash, roadway feature, and traffic volume data.

2. Systemic Analysis—Practitioners use crash and roadway data 

to identify and target improvements at locations throughout a 

network that share risk characteristics for serious crashes.1

The HSIP can help fund projects that improve the 

ways agencies collect and analyze data.
To find out how HSIP can help 

save lives in your community, 

contact your State DOT:

https://www.fhwa.dot.gov/

about/webstate.cfm

Have an HSIP success story? Share your projects on Facebook, 

Twitter, and Instagram with #HSIPSavesLives.

FHWA-SA-22-072 

The HSIP requires States to use crash, roadway, or traffic data in a data-driven safety management process to identify 

and prioritize highway safety improvement projects. This data should be collected using the practices outlined by the 

Federal Highway Administration’s (FHWA’s) Model Inventory of Roadway Elements (MIRE). 

MIRE provides an organizational framework that State, local, and Tribal agencies can use to create more uniform, 

comprehensive, and interconnected databases of roadway characteristics and traffic inventory elements.2 MIRE helps 

agencies with limited resources use advanced tools to improve roadway safety, design, and operation.

MIRE 2.0 introduced MIRE fundamental data elements (FDE).3 This subset was established in Federal regulation with 

subsequent guidance at https://highways.dot.gov/safety/hsip/guidance-state-safety-data-systems. By September 30, 

2026, States must have access to the complete collection of MIRE FDE elements for all public roads.

MIRE FDE guidance helps agencies to improve their roadway inventories and analysis capabilities in several key ways:

2 FHWA, Model Inventory of Road Elements: MIRE 1.0 (October 2010), https://safety.fhwa.dot.gov/tools/data_tools/mirereport/mirereport.pdf.

3 FHWA, Model Inventory of Roadway Elements: MIRE 2.0 (July 2017), https://safety.fhwa.dot.gov/rsdp/downloads/fhwasa17048.pdf.

For more on MIRE, visit https://safety.fhwa.dot.gov/rsdp/mire.aspx.

Meet FDE 

requirements.

Improve overall roadway data 

inventory for all public roads, enabling 

more robust safety analysis.

Improve single elements 

of roadway data.

Create Comprehensive Databases with MIRE FDE

HSIP in Action

Systemic Benefits for Cost-Effective Improvements

PENNSYLVANIA DEPARTMENT OF TRANSPORTATION (PENNDOT)

Over nearly two decades, HSIP-funded PennDOT projects have made safety improvements at 4,300 locations. Since 

2020, PennDOT has used HSIP funds to perform a simple before/after evaluation of observed crashes at each past 

project site to determine the benefit/cost ratio. These reviews revealed which improvement types had the greatest 

benefits, and PennDOT now uses this data to help identify and select subsequent safety improvement projects. 

One key finding was that systemic projects tended to have higher benefit/cost ratios (BCRs) than spot improvement 

projects. The most effective improvement types included rumble strips on both the centerline and edge line (73.8 

BCR), curve-related signing and pavement markings (64.1 BCR), and high friction surface treatment (37.1 BCR). 

Reviews also revealed improvement types that have not been effective at reducing crashes —such as adaptive traffic 

signal control—and these are no longer PennDOT-eligible for HSIP funds. PennDOT is subsequently conducting an 

evaluation of select improvement types using empirical Bayes methods to create high-quality, Pennsylvania-specific 

crash modification factors.

Numerous 

Crashes

PROBLEM

Systemic Safety 

Improvements

SOLUTION RESULT

State-Specific 

Effectiveness 

Evaluation