USA Banner
  U.S. flag
              An official website of the United States government Here's how you knowOfficial US Government Icon
              **Official websites use .gov**A **.gov** website belongs to an official government organization in the United States.
            Secure Site Icon
              **Secure .gov websites use HTTPS**
                  A **lock** ( A locked padlock ) or **https://** means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites. 
 U.S. Department of Transportation Icon United States Department of Transportation
 Search DOT
            Search
                    About FHWAFHWA Organization
                Headquarters Offices
                Field Offices
                Strategic Plan
                Business Opportunities
                Staff Directories
                Careers
                Highway History
                Contact UsProgramsAcquisition Management
                Civil Rights
                Federal Lands Highway
                Infrastructure
                Innovative Program Delivery
                Operations
                Planning, Environment, and Realty
                Policy
                Research, Development, and Technology
                Safety
                Browse by TopicsResourcesCore Highway Topics
                Federal Aid Essentials
                Automation
                Complete Streets
                Laws and Regulations
                Policy & Guidance Center
                Section 508
                Publications and Statistics
                Professional Development
                National Highway Institute
                Resource Center
                Accessibility Resource Library
                FHWA Research LibraryNewsroomPress Releases
                Speeches & Testimony
                Photos
                Videos
                Media ContactsMenu FHWA Highway Safety Programs Home
                        Urbanized and Nonurbanized Safety Target Setting: Final Report


            
            In This Section
        Highway Safety Improvement Program (HSIP)
                                Overview
                About
                Planning
                Implementing
                Evaluating
                Reporting
                Noteworthy Practices
                Legislation and Guidance
                Resources
                HSIP Special Rules
                Strategic Highway Safety Plan (SHSP)
                                Overview
                About
                Develop
                Implement
                Evaluate
                Promote
                Legislation and Guidance
                Resources
                Noteworthy Practices
                Safety Performance Measure
                                Overview
                State Safety Performance Targets
                Policy & Guidance
                Fact Sheets & Informational Webinars
                Target-Setting Resources
                Safety Data Resources
                State Safety Reports
                Safety Contacts
                Technical Assistance & Training
                Railway Highway Crossing Program
                                Overview
                Policy and Guidance
                Resources
                
                4.0 State of the Practice
In this section, because States do not currently track safety data by urbanized and nonurbanized area geographies, the terms urban and rural are used. Review of the most recent SHSPs, HSPs (FY 2014) and HSIP Annual Reports (FY 2013) in all 50 States revealed only one State (Georgia) sets urban or rural targets in its SHSP( Figure 4.1, left). A number of States include urban and rural fatality, serious injury, or crash *data* in their SHSPs to track overall trends (Figure 4.1, right). Of those, some track the extent to which crashes within an SHSP emphasis area are urban or rural.

**4.1 Existence of Urban and Rural Targets and Crash Data Analysis in Strategic Highway Safety Plans**

Figure 4.1	Existence of Urban and Rural Targets and Crash Data Analysis in Strategic Highway Safety Plans


States more commonly include safety targets for urban and rural areas in HSPs than in other State safety documents. This can be attributed to the 2008 *Traffic Safety Performance Measures for States and Federal Agencies* document which notes, “States should report both rural and urban fatalities/VMT as well as total fatalities/VMT.” More than half of HSPs include urban fatality targets (Figure 4.2 left), but only one includes an urban serious injury target. Nearly all HSPs track rates and/or numbers of urban and rural fatalities, but only a few States include urban and rural serious injury data (Figure 4.2, right).

**Figure 4.2 Existence of Urban and Rural Targets and Crash Data Analysis in Highway Safety Plans**

Figure 4.2	Existence of Urban and Rural Targets and Crash Data Analysis in Highway Safety Plans


As there is no current requirement, no States report urban or rural safety targets in HSIP Annual Reports. Some HSIP reports include data on urban and rural crashes, as shown in Figure 4.3. Moving forward, it is expected States will begin to report safety targets in these documents, as proposed in the Safety PM NPRM.

**Figure 4.3 Existence of Urban and Rural Crash Data Analysis in Highway Safety Improvement Program Annual Reports**

Figure 4.3	Existence of Urban and Rural Crash Data Analysis in Highway Safety Improvement Program Annual Reports


The research team analyzed FARS data using GIS to calculate the proportion of fatalities in urbanized and nonurbanized areas according to the FHWA adjusted urbanized area geography using the most recent boundary data available for all States (2000). Table 4.1 summarizes the annual average number and percent of statewide fatalities located in urbanized and nonurbanized areas over a five-year period (2007-2011). In those cases where the sum of urbanized and nonurbanized area fatalities is less than the total, some fatalities were not able to be geolocated (e.g., location data were incorrect or missing). As noted previously, the FHWA *adjusted urbanized*13 area boundary includes only areas with population over 50,000. There is wide variation across States in the percentage of fatalities that occur in urbanized areas, ranging from six percent for North Dakota to 84 percent in Massachusetts, which is a reflection of the extent to which the land area is urbanized in a State. On a national level, 41 percent of fatalities occur in urbanized areas and 58 percent in nonurbanized areas.

**Table 4.1 Annual Average Fatalities in Urbanized and Nonurbanized Areas *2007-2011***

State
			Total Annual Average Fatalities
			Annual Average Nonlocatable Fatalities
			FHWA 2000 Urbanized Area Fatalities
			Percent Urbanized Area Fatalities
			FHWA 2000 Nonurbanized Area Fatalities
			Percent Nonurbanized FatalitiesAlabama
			936
			1
			292
			31%
			643
			69%Alaska
			67
			0
			20
			29%
			47
			70%Arizona
			870
			35
			382
			44%
			453
			56%Arkansas
			593
			1
			107
			18%
			485
			82%California
			3,206
			2
			1,929
			60%
			1,275
			40%Colorado
			493
			0
			196
			40%
			297
			60%Connecticut
			272
			4
			203
			74%
			65
			25%Delaware
			111
			0
			45
			40%
			66
			60%Florida
			2,719
			76
			1,724
			64%
			919
			37%Georgia
			1,355
			59
			501
			37%
			795
			63%Hawaii
			113
			4
			40
			36%
			69
			64%Idaho
			217
			0
			28
			13%
			190
			87%Illinois
			1,009
			0
			517
			51%
			493
			49%Indiana
			779
			11
			244
			31%
			524
			69%Iowa
			396
			1
			70
			18%
			325
			82%Kansas
			401
			1
			81
			20%
			319
			80%Kentucky
			792
			1
			139
			18%
			652
			82%Louisiana
			826
			2
			268
			32%
			556
			68%Maine
			159
			1
			20
			13%
			138
			87%Maryland
			546
			5
			330
			60%
			211
			40%Massachusetts
			364
			9
			307
			84%
			48
			16%Michigan
			954
			0
			435
			46%
			519
			54%Minnesota
			433
			0
			111
			26%
			322
			74%Mississippi
			727
			0
			96
			13%
			631
			87%Missouri
			887
			1
			262
			30%
			624
			70%Montana
			225
			0
			19
			9%
			206
			91%Nebraska
			212
			0
			31
			15%
			181
			85%Nevada
			289
			1
			160
			55%
			128
			44%New Hampshire
			119
			0
			34
			28%
			85
			72%New Jersey
			616
			7
			453
			74%
			156
			26%New Mexico
			368
			0
			77
			21%
			292
			79%New York
			1,199
			110
			727
			61%
			362
			39%North Carolina
			1,381
			75
			394
			29%
			912
			71%North Dakota
			122
			1
			7
			6%
			114
			94%Ohio
			1,113
			1
			465
			42%
			647
			58%Oklahoma
			723
			14
			155
			21%
			554
			79%Oregon
			379
			1
			86
			23%
			292
			77%Pennsylvania
			1,365
			3
			552
			41%
			810
			60%Rhode Island
			70
			0
			55
			79%
			15
			21%South Carolina
			906
			1
			240
			27%
			665
			73%South Dakota
			130
			0
			9
			7%
			121
			93%Tennessee
			1,044
			1
			364
			35%
			679
			65%Texas
			3,215
			46
			1,378
			43%
			1791
			57%Utah
			262
			0
			115
			44%
			147
			56%Vermont
			68
			1
			6
			10%
			61
			91%Virginia
			823
			46
			304
			37%
			473
			63%Washington
			499
			3
			206
			41%
			290
			59%West Virginia
			364
			1
			54
			15%
			309
			85%Wisconsin
			615
			0
			150
			24%
			466
			76%Wyoming
			146
			1
			12
			9%
			133
			91%**TOTAL**
			**35,476**
			**2**
			**14,402**
			**41%**
			**21,074**
			**59%**Source: Cambridge Systematics, Inc.

To calculate fatality rates for adjusted urbanized areas, it was necessary to obtain VMT data from FHWA. Currently, VMT data are provided for urbanized areas on the FHWA Highway Statistics website, but data are provided in the aggregate for urbanized areas spanning multiple States. Therefore, FHWA provided calculations for urbanized area VMT by State for use in this report. Each State must calculate VMT for its annual submission to the Highway Performance Monitoring System (HPMS) maintained by FHWA and should be in possession of its urbanized area VMT.

Table 4.2 shows average annual fatality rates using 2007-2011 FARS data and 2009-2011 VMT data. Ideally, a five-year average of VMT data would be used with five-year average fatalities, but for this study only select years of urbanized area VMT data by State were available. In every State, the nonurbanized fatality rate was higher than the urbanized fatality rate and statewide fatality rate. However, based on the research cited in Section 1, a large proportion of rural crashes are expected to be within five to 10 miles of the urban area boundary. Statewide fatality rates range from 0.70 in Massachusetts to 2.03 in Montana. Urbanized area fatality rates are between 0.42 for Minnesota and 1.49 in Nevada, and nonurbanized fatality rates range from 1.08 in Minnesota to 2.95 in Nevada.

**Table 4.2 FHWA 2000 Adjusted Urbanized Area Fatality Rates**

State
			Statewide Fatality Rate
			Urbanized Area Fatality Rate
			Nonurbanized Area Fatality RateAlabama
			1.48
			1.15
			1.69Alaska
			1.46
			1.22
			1.59Arizona
			1.45
			1.00
			2.27Arkansas
			1.79
			0.98
			2.18California
			1.01
			0.78
			1.83Colorado
			1.06
			0.70
			1.61Connecticut
			0.89
			0.79
			1.41Delaware
			1.28
			0.90
			1.79Florida
			1.40
			1.14
			2.31Georgia
			1.30
			0.83
			1.93Hawaii
			1.20
			0.80
			1.65Idaho
			1.41
			0.54
			1.84Illinois
			0.99
			0.74
			1.56Indiana
			1.08
			0.65
			1.54Iowa
			1.29
			0.77
			1.51Kansas
			1.34
			0.67
			1.80Kentucky
			1.68
			0.93
			2.04Louisiana
			1.83
			1.25
			2.35Maine
			1.12
			0.69
			1.23Maryland
			1.00
			0.84
			1.37Massachusetts
			0.70
			0.65
			1.12Michigan
			1.01
			0.76
			1.42Minnesota
			0.77
			0.42
			1.08Mississippi
			1.88
			0.98
			2.19Missouri
			1.33
			0.81
			1.81Montana
			2.03
			1.30
			2.14Nebraska
			1.12
			0.49
			1.43Nevada
			1.91
			1.49
			2.95New Hampshire
			0.92
			0.61
			1.16New Jersey
			0.88
			0.73
			2.17New Mexico
			1.47
			1.01
			1.67New York
			0.95
			0.83
			1.24North Carolina
			1.34
			0.76
			1.92North Dakota
			1.45
			0.47
			1.68Ohio
			1.00
			0.69
			1.46Oklahoma
			1.53
			0.79
			2.05Oregon
			1.15
			0.58
			1.61Pennsylvania
			1.39
			0.99
			1.89Rhode Island
			0.87
			0.79
			1.39South Carolina
			1.87
			1.18
			2.38South Dakota
			1.46
			0.53
			1.67Tennessee
			1.53
			1.07
			1.99Texas
			1.41
			0.94
			2.27Utah
			1.05
			0.72
			1.62Vermont
			1.26
			0.82
			1.34Virginia
			1.03
			0.64
			1.60Washington
			0.90
			0.56
			1.54West Virginia
			1.91
			1.00
			2.27Wisconsin
			1.06
			0.63
			1.37Wyoming
			1.58
			1.19
			1.63**TOTAL**
			**1.23**
			**0.84**
			**1.80**Source: Fatality Rate based on annual average 2007-2011 FARS and 2009-2011 VMT provided by FHWA.

When comparing two States using fatality rates, one State may appear to be safer than another based on a comparison of their statewide fatality rates; however, the other State could look safer based on a comparison of urbanized and nonurbanized fatality rates. This phenomenon is known as Simpson’s Paradox. Simpson’s Paradox represents the statistical phenomenon of stratifying aggregate data into two or more groups, and finding that analysis of the smaller groups results in opposing conclusions. It illustrates how the safety profile of a State is affected by the proportion of urbanized and nonurbanized VMT in the calculation.

Table 4.3 shows California has a lower statewide fatality rate than South Dakota; therefore, California roads appear safer. However, the fatality rates for urbanized and nonurbanized areas are both lower in South Dakota than in California. This phenomenon is referred to as Simpson’s Paradox.

**Table 4.3 Simpson's Paradox Illustration**

State
			Percent Urbanized Area VMT
			Percent Nonurbanized Area VMT
			Statewide Fatality Rate
			Urbanized Area Fatality Rate
			Nonurbanized Area Fatality RateCalifornia
			78%
			22%
			1.01
			0.78
			1.83South Dakota
			19%
			81%
			1.46
			0.53
			1.67Source: Fatality Rate based on annual average 2007-2011 FARS and 2009 VMT provided by FHWA.

A national dataset does not exist with comprehensive, high quality injury crash data like the FARS database for fatal crashes. To conduct GIS analysis of crash locations and determine the proportion of urbanized and nonurbanized serious injury crashes, locations of all serious injury crashes on all public roads are needed for at least one if not multiple three- to five-year periods. To analyze the proportion of urbanized versus nonurbanized serious injuries, the study team contacted crash records managers in all 50 States to request data on serious injuries maintained in State crash records systems.

Through discussions with States and review of the data provided, the study team obtained usable data by 20 States, which is presented in Table 4.4. For each State five years of data were used, but not all time periods were consistent, as noted in the columns to the right. The percentage of serious injuries in urbanized areas is higher than for fatalities. Crashes in urbanized areas are different from those in nonurbanized areas (e.g., there are more bicycle, pedestrian, and intersection crashes in urbanized areas). Generally speeds tend to be slower in urbanized areas so crashes are likely to be less severe, resulting in a higher proportion of serious injuries in urbanized areas compared to fatalities. In addition, crashes in urbanized areas are generally closer to trauma centers, and prompt treatment is known to reduce overall injury severity.

**Table 4.4 Serious Injury Numbers for Select States**

State
			Percent Urbanized
			Percent Nonurbanized
			Number of Serious Injuries
			Number of Urbanized Serious Injuries
			Number of Nonurbanized Serious Injuries
			Start Year
			End YearAlaska
			51.6%
			48.4%
			435
			225
			211
			2006
			2010Arizona
			67.1%
			32.9%
			5,020
			3,367
			1,652
			2008
			2012Colorado
			49.2%
			50.8%
			4,128
			2,033
			2,096
			2008
			2012Iowa
			30.7%
			69.3%
			1,694
			520
			1,175
			2008
			2012Illinois
			66.5%
			33.5%
			9,704
			6,456
			3,248
			2008
			2012Louisiana
			43.2%
			56.8%
			1,424
			616
			808
			2008
			2012Maine
			27.7%
			72.3%
			636
			176
			460
			2008
			2012Michigan
			50.6%
			49.4%
			6,116
			3,093
			3,022
			2008
			2012Minnesota
			22.3%
			77.7%
			1,268
			283
			984
			2008
			2012Missouri
			39.3%
			60.7%
			6,143
			2,416
			3,727
			2008
			2012Montana
			13.4%
			86.6%
			1,094
			147
			947
			2008
			2012Nebraska
			33.8%
			66.2%
			1,721
			582
			1,139
			2007
			2011New Jersey
			64.1%
			35.9%
			1,532
			982
			550
			2008
			2012New York
			68.9%
			31.1%
			12,932
			8,912
			4,019
			2008
			2012Ohio
			52.1%
			47.9%
			9,720
			5,061
			4,659
			2008
			2012Oklahoma
			39.4%
			60.6%
			3,663
			1,445
			2,218
			2008
			2012Oregon
			43.3%
			56.7%
			1,537
			666
			871
			2008
			2012Pennsylvania
			46.5%
			53.5%
			2,871
			1,335
			1,537
			2008
			2012South Dakota
			21.7%
			78.3%
			837
			182
			655
			2008
			2012Texas
			50.7%
			49.3%
			15,459
			7,839
			7,621
			2009
			2013Source: Cambridge Systematics and State crash databases.

Table 4.5 presents serious injury rates, which are significantly higher than fatality rates given the numbers of serious injury crashes are higher than fatal crashes. The table presents annual average data for a five-year period, but not all time periods are consistent as noted by the columns indicating the years included in the analysis.

**Table 4.5 Serious Injury Rates for Selected States**

State
			Annual Average Number of Serious Injuries
			Statewide Serious Injury Rate
			Urbanized Area Serious Injury Rate
			Nonurbanized Serious Injury Rate
			Start Year
			End YearAlaska
			435
			9.4
			13.7
			7.1
			2006
			2010Arizona
			5,020
			8.4
			8.8
			7.7
			2008
			2012Colorado
			4,128
			8.9
			7.2
			11.4
			2008
			2012Iowa
			1,694
			5.5
			5.7
			5.5
			2008
			2012Illinois
			9,704
			9.5
			9.2
			10.3
			2008
			2012Louisiana
			1,424
			3.2
			2.9
			3.4
			2008
			2012Maine
			636
			4.5
			6.1
			4.1
			2008
			2012Michigan
			6,116
			6.5
			5.4
			8.3
			2008
			2012Minnesota
			1,268
			2.3
			1.1
			3.3
			2008
			2012Missouri
			6,143
			9.2
			7.4
			10.8
			2008
			2012Montana
			1,094
			9.9
			10.0
			9.8
			2008
			2012Nebraska
			1,721
			9.1
			9.2
			9.0
			2007
			2011New Jersey
			1,532
			2.2
			1.6
			7.3
			2008
			2012New York
			12,932
			10.3
			10.1
			10.6
			2008
			2012Ohio
			9,720
			8.7
			7.5
			10.5
			2008
			2012Oklahoma
			3,663
			7.7
			7.3
			8.0
			2008
			2012Oregon
			1,537
			4.7
			4.5
			4.8
			2008
			2012Pennsylvania
			2,871
			2.9
			2.4
			3.6
			2008
			2012South Dakota
			837
			9.4
			10.8
			9.1
			2008
			2012Texas
			15,459
			6.8
			5.3
			9.4
			2009
			2013Source: Cambridge Systematics, State crash databases, VMT data for 2009-2011 provided by FHWA.

13When the term FHWA adjusted *urban* boundary is used in other contexts, this includes areas with population above 5,000.
      
  Book traversal links for 4.0 State of the Practice
      ‹ 3.0 Geography Definition
                    Up
                    5.0 Safety Target Setting Framework ›
                
                Book:Urbanized and Nonurbanized Safety Target Setting: Final Report
              1.0 Introduction
                2.0 Background
                3.0 Geography Definition
                4.0 State of the Practice
                5.0 Safety Target Setting Framework
                6.0 Data and Methods for Evidence-Based Urbanized and Nonurbanized Targets
                7.0 Technical Methods for Target Setting
                8.0 Conclusion U.S. DEPARTMENT OF TRANSPORTATION

**Federal Highway Administration**

1200 NEW JERSEY AVENUE, SE

WASHINGTON, DC 20590

202-366-4000Subscribe to email updates
                    About
  

        
              About FHWA
                Careers
                Org Chart
                Staff Directories
                Work with UsPrograms
  

        
              Acquisition Management
                Civil Rights
                Federal Lands Highway
                Infrastructure
                Innovative Program Delivery
                Operations
                Planning, Environment, and Realty
                Policy
                Research, Development, and Technology
                SafetyPolicies, Rights, Legal
  

        
              About DOT
                Accessibility
                Budget and Performance
                Civil Rights
                FOIA
                Information Quality
                No FEAR Act
                Office of Inspector General
                Privacy Policy
                USA.gov
                Web Policies and Notices
                Web StandardsNews & Events
  

        
              Newsroom
                Press Releases
                Speeches & Testimony
                Media Contacts
                Connect with Us