http://safety.fhwa.dot.gov

Local and Rural Road Safety Briefing Sheets

Local and Rural Road Safety Data

Introduction

The process of identifying, analyzing, and treating roadway safety problems on local and rural roads relies heavily on 

the availability of road safety data. Crash reports completed by law enforcement officers are combined with roadway 

characteristic and traffic volume data gathered by traffic engineering or public works staff to identify crash history, 

analyze risk factors, establish needs, and evaluate treatments. Law enforcement and engineering agencies need to work 

together closely to understand the requirements for safety data and the importance of this information in developing 

plans and programs to treat road safety issues. This document highlights the types of information required, the 

application of this information, and additional resources that can be consulted by local and rural road owners to improve 

safety data for their agency. 

How are Safety Data Used?

Funding programs administered by the State Departments of Transportation, such as the Highway Safety Improvement 

Program (HSIP), rely upon a data‐driven safety planning process. Applying for local or rural road safety project funding 

oftentimes requires the applicant to use safety data as part of the safety planning process to justify the need for the 

project. Therefore, local agencies that collect, store, and process safety data are better positioned to compete for 

funding under these programs. 

The safety planning process consists of four steps:1

Step 1: Collect Crash, Roadway and Traffic Data2

Law enforcement investigated crash reports are the principal sources of information for crash data. State and local law 

enforcement officers complete a standard form3

 that generally captures the following data:4

In addition to crash data, roadway characteristic and traffic data typically collected by engineering or public works 

agencies are useful to help identify risks and to choose appropriate countermeasures. These data include:

• Date & time of crash

• Crash severity

(e.g., fatal injury, property damage only)

• Crash type (e.g., angle, rear-end, head-o

run-off-the-ro

• Location 

• Site Conditions (e.g., weather, surface conditions, 

lighting)

• Number and types of vehicles involved

• Driver information (e.g., name, age, gender)

• Passenger data

• Contributing circumstances

• Step 1: Collect Crash, Roadway, and Traffic Data 

• Step 2: Record Information for Safety Analysis

• Step 3: Analyze Data

• Step 4: Select and Prioritize Countermeasures

• Roadway surface type

• Number of Lanes and width(s)

• Shoulder type and width

• Median type and width

• Roadway miles

• Roadway alignment (horizontal and vertical)

• ntersection configuration

• Traffic control devices

• Number and locations of driveways

• Traffic volume

• Intersection type
Step 2: Record Information for Analysis

Crash data are compiled and recorded by the State or local (e.g. city, county, and township) law enforcement officers 

at the reportable crash scene. Later, their crash data are entered into a database for storage and processing. Roadway 

characteristics and traffic data are collected by State and local transportation agencies to populate roadway inventory 

databases. Agencies with data processing capability and expertise will use electronic data processing, whereas those 

with limited funds and no electronic data processing capabilities may rely on a paper-based record of crashes and

manual processing. 

Step 3: Analyze Data

Crash, roadway, and traffic data are combined to analyze crash patterns for the purpose of identifying high-crash

locations, crash trends, and potential improvement strategies. There are a number of methods that can be used 

to characterize crash patterns, including crash frequencies, rates, severity of crashes, location of crashes, over

representation of certain types of crashes in the data set, and driver actions such as speeding, failure to yield the right

of-way, and impairment. The results of the data analysis are examined to determine patterns in crash types, locations,

and potential causes.

Step 4: Select Countermeasures

Improvement strategies or safety countermeasures are selected to treat identified safety problems. There are many 

potential strategies available to treat problems depending on the contributing factors. Safety professionals generally 

classify these into four categories: engineering, enforcement, education, and emergency response (4E’s).5

 Crash 

patterns and characteristics provide a basis to understand the type of actions needed to treat a particular safety 

problem. For example, analysis of crash data at an intersection may suggest the need to modify the geometric design 

or traffic control to reduce a high frequency of right-angle crashes. A high frequency of crashes related to speeding

may indicate a need to increase enforcement. A comprehensive approach is generally the best option.

Alternative Methods for Processing Safety Information

Storing, retrieving, and processing crash data can be time consuming and costly. Electronic data processing systems 

can reduce the burden. However, local and rural agencies often times do not have the financial or staff resources 

required to develop or maintain a system. In such cases, compiling and storing crash reports can be accomplished by 

combining manual and electronic data processing. For example, one county government reported using high school 

interns to enter crash data into an Excel spreadsheet for processing. University students may be available to assist in 

developing and designing a system in exchange for college credit.6

 This can reduce development costs for local and 

rural road agencies while providing a level of electronic data processing capability. 

As an alternative to formal crash databases and crash reports, agencies, police officers, and maintenance staff may be 

consulted to identify high-risk locations. Physical evidence such as skid marks at a crash site and maintenance records

indicative of crash-related damage could be used to identify existing safety problems and sites for potential safety

treatment. Local residents may report problem locations to the local engineer and public officials, who can identify 

locations based on citizen complaints. Road Safety Audits7

 can also be used to identify and make recommendations to 

mitigate the safety issues identified. 
While it may take more effort to collect data from the aforementioned sources, methods exist to address lack of 

complete crash data. For example, roadway features that are generally related to particular crash types might be 

identified as candidates for systemic, low-cost treatments in the absence of crash data. Identifying higher risk locations

based on the presence of roadway features with known risk can be useful in identifying the need for safety treatments 

on a system-wide basis

Example

The table below summarizes lane departure crash data that Thurston County, WA assembled for the 2006 – 2010 time 

period from the Washington State Department of Transportation (WSDOT) crash database. The table compares this 

local data against statewide averages during the same period.8

 Between 2006 and 2010, 177 fatal and serious injury 

crashes occurred in Thurston County. The data shows that the horizontal curve crashes are overrepresented in the 

County. In addition, the proportion of roadway departure crashes in horizontal curves is greater in Thurston County 

than for either the combined County roadway system in Washington or the statewide roadway system. As a result, 

Thurston County selected lane departure crashes on horizontal curves as their focus crash type.

Crash Data for Lane Departure Crashes Thurston County, WA, 2006-2010 (Percentage

2006 – 2010 Collision History

Fatal & Serious 

Crashes – Thurston 

County (%)

Fatal & Serious 

Crashes – 

Statewide (%)

Difference 

(%)

Overall Numbers Total number of collisions 3 2 1

By Collision Type Hit fixed object 48 27 21

Overturn 10 11 (1)

Angle (left turn) 9 16 (7)

Head on 7 5 2

By Light Condition Daylight 52 58 (6)

Dark – no street lights 33 16 17

By Junction Relationship Intersection-related 19 33 (14

Driveway-related 5 7 (2

Non-Intersection 77 60 1

Hit Fixed Object Crashes Only – 

By Fixed Object Hit

Tree/stump (stationary) 14 5 9

Roadway ditch 7 3 4

Utility pole 7 3 4

By Roadway Curvature Straight and level 42 54 (12)

Horizontal curve (all) 45 26 19

By Speed Limit

(Number of Drivers)

35 mph 28 35 (7)

50 mph 69 16 53

By Contributing Circumstance 

(Number of Drivers)

Exceeding safe/stated speed 48 31 17

Under influence of alcohol/ drugs 42 25 17

Over centerline 16 10 6

Inattention/distraction 11 13 (2)

By Driver Age Group Ages 16-20 26 20 

Ages 41-50 28 26 

By Seat Belt/Car Seat Use 

(Number of Occupants) No restraint 33 25 8
An inspection of the data contained in this table suggests that during this period lane departure crashes in Thurston 

County, when compared against the statewide average, were more likely to involve: striking a fixed object, during dark, 

at non-intersection locations, on horizontal curves, on roads with a 50 mph speed limit, and while exceeding safe/posted

speed, under the influence of alcohol/drugs. Based on these data, Thurston County pursued a program to focus on 

treating lane departure crashes at horizontal curves.

Resources

There is a wide range of resources available that can assist local and rural road users in improving safety data collection, 

processing, and application.

AASHTO, Highway Safety Manual: Volume 3 – Crash Modification Factors (Washington, DC: 2010).

Federal Highway Administration, Roadway Safety Information Analysis: A Manual for Local Rural Road 

Owners, FHWA-SA-11-1.  (Washington, DC: January 201

T. MacDonald, Iowa’s Traffic Safety Analysis Manual (Ames, IA: Iowa State University, December 2011).

T Strauss and L. Geadelmann, Evaluation Framework for the Creation and Analysis of Integrated 

Spatially-Referenced Driver-Crash Database (Ames, IA: Midwest Transportation Consortium, April 2009).

Transportation Research Board, NCHRP Synthesis 321: Roadway Safety Tools for Local Agencies: A Synthesis 

of Highway Practice, National Cooperative Highway Research Program (Washington, DC: TRB, 2004).

Transportation Research Board, NCHRP Report 500: Guidance for Implementation of the AASHTO 

Strategic Highway Safety Plan, Volume 19: A Guide for Collecting and Analyzing Safety Highway Safety 

Data Volume. (Washington, DC: TRB, 2005).

Transportation Research Board, NCHRP Report 500: Guidance for Implementation of the AASHTO 

Strategic Highway Safety Plan, Volume 21: Safety Data and Analysis in Developing Emphasis Area Plans

(Washington, DC: TRB, 2005).

1

 Federal Highway Administration, Roadway Safety Information Analysis: A Manual for Local Rural Road Owners (Washington, DC: 

January 2011), p. 10.

2

 Moving Ahead for Progress in the 21st Century Act (MAP-21) (P.L. 112-141) requires State Departments of Transportation (DOTs) t

develop safety data systems to support safety analysis. 

3

 These forms can vary by jurisdiction so it is important that local and rural road operators recognize the need to provide a 

consistent form reflecting the needs of their information system. 

4

 Sometimes the crash diagram and narrative on the crash report have the most information about how the crash occurred and 

input from the drivers and witnesses.

5

 For examples of countermeasures see the Federal Highway Administration’s Crash Modification Factors (CMF) Clearinghouse, 

available online at: www.cmfclearinghouse.org

6

 Steps to ensure privacy is maintained should be put in place.

7

 Road Safety Audit (RSA) is the formal safety performance examination of an existing or future road or intersection by an 

independent, multidisciplinary team.

8 Federal Highway Administration, Systemic Safety Project Selection Tool, FHWA-SA-13-019 (Washington, DC: July 201

Available at: http://safety.fhwa.dot.gov/systemic/fhwasa13019/

FHWA-SA-14-