20231108 08085900 1.0 TRUE This dataset contained lane departure crash data grouped by one mile roadway segments on State maintained roadways in North Carolina. This date range for the analysis is June 1, 2018 through May 31, 2023.Lane departure crashes are defined as the following crash types on the crash report form: Lane Departure (right, left, and straight), overturn/rollover, fixed object, parked motor vehicle, head on, and sideswipe opposite direction).This data should be viewed as planning level data only. If detailed crash data is needed for a specific location for decision making purposes, it should be requested from the NCDOT Traffic Safety Unit.The shapefile for this data can be downloaded <a href='https://ncdot.maps.arcgis.com/home/item.html?id=5944e5e56081415f986af37ad263533b' target='_blank' rel='nofollow ugc noopener noreferrer'>HERE</a> Column Definitions:<ul><li>COUNTY – County Number</li><li>ROUTE – 8 digit route code</li><li>BEGIN MP – Beginning milepost of section</li><li>END MP – End milepost of section</li><li>CRASH DENSITY RATIO (CDR) – See “Section Scoring” section below</li><li>SEVERITY INDEX (SI) – Average of the EPDO (equivalent property damage only) of the crashes on the section. Property damage only (PDO) crashes are given a value of a 1, ‘B’ (moderate) and ‘C’ (minor) injury crashes are given a value of 8.4, and ‘A’ (severe) and ‘K’ (fatal) crashes are given a value of 76.8.</li><li>CRASH RATE RATIO (CRR) – See “Section Scoring” section below</li><li>DENSITY SCORE – Score based on Crash Density Ratio (CDR). </li><li>SEVERITY SCORE – Score based on severity index</li><li>CRASH RATE SCORE – Score based on crash rate ratio</li><li>COMBINED SCORE – Average of the 3 scores (density, severity, and crash rate)</li><li>COMBINED RANGE – Scores were broken into 3 ranges, 0 to 33, 33 to 66, or 66 to 100.</li><li>FATAL AND SEVERE INJURY CRASH COUNT – Count of the ‘K’ and ‘A’ injury lane departure crashes on the section</li><li>MODERATE AND MINOR INJURY CRASH COUNT – Count of ‘B’ and ‘C’ lane departure crashes on the section</li><li>PROPERTY DAMAGE ONLY CRASH COUNT – Count of PDO lane departure crashes on the section</li><li>TOTAL CRASH COUNT – Total lane departure crash count on the section</li></ul> Section Safety Scoring Section Scoring: Points for highway section projects are scored based on three components (USING LANE DEPARTURE CRASHES ONLY): 1) Class Density Ratio – The crash density of the study area versus the average crash density of similar facilities; 2) Severity Index; and 3) Critical Crash Rate Ratio – The actual crash rate for the study area versus the critical crash rate. The point breakdown for each component is shown in the table below. The points from the three safety score components are added, and then the sum is divided by three. The project areas with the higher scores are considered to have the poorer highway safety performance. <table border='0' cellpadding='0' cellspacing='0' style='margin-bottom:1.5rem; width:323.4pt; border-collapse:collapse; border-spacing:0px; border:1px solid rgb(204, 204, 204); font-size:0.875rem; font-family:"Avenir Next W01", "Avenir Next W00", "Avenir Next", Avenir, "Helvetica Neue", sans-serif; margin-left:54.75pt;' width='431'><tbody><tr style='border-bottom:1px solid rgb(204, 204, 204); height:12.75pt;'><td style='border-left:1px solid rgb(204, 204, 204); border-right:1px solid rgb(204, 204, 204); padding:0in 5.4pt; width:51pt; height:12.75pt;' valign='bottom' width='68'> </td><td colspan='2' style='border-left:1px solid rgb(204, 204, 204); border-right:1px solid rgb(204, 204, 204); padding:0in 5.4pt; width:97.8pt; height:12.75pt;' valign='bottom' width='130'>Class Density Ratio</td><td colspan='2' style='border-left:1px solid rgb(204, 204, 204); border-right:1px solid rgb(204, 204, 204); padding:0in 5.4pt; width:87.8pt; height:12.75pt;' valign='bottom' width='117'>Severity Index1</td><td colspan='2' style='border-left:1px solid rgb(204, 204, 204); border-right:1px solid rgb(204, 204, 204); padding:0in 5.4pt; width:86.8pt; height:12.75pt;' valign='bottom' width='116'>Critical Crash Rate Ratio2</td></tr><tr style='border-bottom:1px solid rgb(204, 204, 204); height:12.75pt;'><td style='border-left:1px solid rgb(204, 204, 204); border-right:1px solid rgb(204, 204, 204); padding:0in 5.4pt; width:51pt; height:12.75pt;' valign='bottom' width='68'>Points</td><td colspan='2' style='border-left:none; border-right:none; padding:0in 5.4pt; width:97.8pt; border-top:none; border-image:initial; border-bottom:1pt solid windowtext; height:12.75pt;' valign='bottom' width='130'>range</td><td colspan='2' style='border-left:none; border-right:none; padding:0in 5.4pt; width:87.8pt; border-top:none; border-image:initial; border-bottom:1pt solid windowtext; height:12.75pt;' valign='bottom' width='117'>range</td><td colspan='2' style='border-left:none; border-right:none; padding:0in 5.4pt; width:86.8pt; border-top:none; border-image:initial; border-bottom:1pt solid windowtext; height:12.75pt;' valign='bottom' width='116'>range</td></tr><tr style='border-bottom:1px solid rgb(204, 204, 204); height:12.75pt;'><td style='border-left:1px solid rgb(204, 204, 204); border-right:1px solid rgb(204, 204, 204); padding:0in 5.4pt; width:51pt; height:12.75pt;' valign='bottom' width='68'>100</td><td style='border-left:1pt solid windowtext; border-right:none; padding:0in 5.4pt; width:48.9pt; border-top:none; border-bottom:none; border-image:initial; height:12.75pt;' valign='bottom' width='65'>1.4</td><td style='border-left:1px solid rgb(204, 204, 204); border-right:1px solid rgb(204, 204, 204); padding:0in 5.4pt; width:48.9pt; height:12.75pt;' valign='bottom' width='65'>---</td><td style='border-left:1pt solid windowtext; border-right:none; padding:0in 5.4pt; width:49.3pt; border-top:none; border-bottom:none; border-image:initial; height:12.75pt;' valign='bottom' width='66'>5.94</td><td style='border-left:1px solid rgb(204, 204, 204); border-right:1px solid rgb(204, 204, 204); padding:0in 5.4pt; width:38.5pt; height:12.75pt;' valign='bottom' width='51'>---</td><td style='border-left:1pt solid windowtext; border-right:none; padding:0in 5.4pt; width:43.4pt; border-top:none; border-bottom:none; border-image:initial; height:12.75pt;' valign='bottom' width='58'>0.78</td><td style='border-left:none; border-right:1pt solid windowtext; padding:0in 5.4pt; width:43.4pt; border-top:none; border-bottom:none; border-image:initial; height:12.75pt;' valign='bottom' width='58'>---</td></tr><tr style='border-bottom:1px solid rgb(204, 204, 204); height:12.75pt;'><td style='border-left:1px solid rgb(204, 204, 204); border-right:1px solid rgb(204, 204, 204); padding:0in 5.4pt; width:51pt; height:12.75pt;' valign='bottom' width='68'>66.7</td><td style='border-left:1pt solid windowtext; border-right:none; padding:0in 5.4pt; width:48.9pt; border-top:none; border-bottom:none; border-image:initial; height:12.75pt;' valign='bottom' width='65'>0.68</td><td style='border-left:1px solid rgb(204, 204, 204); border-right:1px solid rgb(204, 204, 204); padding:0in 5.4pt; width:48.9pt; height:12.75pt;' valign='bottom' width='65'>1.4</td><td style='border-left:1pt solid windowtext; border-right:none; padding:0in 5.4pt; width:49.3pt; border-top:none; border-bottom:none; border-image:initial; height:12.75pt;' valign='bottom' width='66'>1.94</td><td style='border-left:1px solid rgb(204, 204, 204); border-right:1px solid rgb(204, 204, 204); padding:0in 5.4pt; width:38.5pt; height:12.75pt;' valign='bottom' width='51'>5.93</td><td style='border-left:1pt solid windowtext; border-right:none; padding:0in 5.4pt; width:43.4pt; border-top:none; border-bottom:none; border-image:initial; height:12.75pt;' valign='bottom' width='58'>0.41</td><td style='border-left:none; border-right:1pt solid windowtext; padding:0in 5.4pt; width:43.4pt; border-top:none; border-bottom:none; border-image:initial; height:12.75pt;' valign='bottom' width='58'>0.77</td></tr><tr style='border-bottom:1px solid rgb(204, 204, 204); height:12.75pt;'><td style='border-left:1px solid rgb(204, 204, 204); border-right:1px solid rgb(204, 204, 204); padding:0in 5.4pt; width:51pt; height:12.75pt;' valign='bottom' width='68'>33.3</td><td style='border-left:1pt solid windowtext; border-right:none; padding:0in 5.4pt; width:48.9pt; border-top:none; border-bottom:none; border-image:initial; height:12.75pt;' valign='bottom' width='65'>0.24</td><td style='border-left:1px solid rgb(204, 204, 204); border-right:1px solid rgb(204, 204, 204); padding:0in 5.4pt; width:48.9pt; height:12.75pt;' valign='bottom' width='65'>0.67</td><td style='border-left:1pt solid windowtext; border-right:none; padding:0in 5.4pt; width:49.3pt; border-top:none; border-bottom:none; border-image:initial; height:12.75pt;' valign='bottom' width='66'>1</td><td style='border-left:1px solid rgb(204, 204, 204); border-right:1px solid rgb(204, 204, 204); padding:0in 5.4pt; width:38.5pt; height:12.75pt;' valign='bottom' width='51'>1.93</td><td style='border-left:1pt solid windowtext; border-right:none; padding:0in 5.4pt; width:43.4pt; border-top:none; border-bottom:none; border-image:initial; height:12.75pt;' valign='bottom' width='58'>0.2</td><td style='border-left:none; border-right:1pt solid windowtext; padding:0in 5.4pt; width:43.4pt; border-top:none; border-bottom:none; border-image:initial; height:12.75pt;' valign='bottom' width='58'>0.4</td></tr><tr style='border-bottom:none; height:12.75pt;'><td style='border-left:1px solid rgb(204, 204, 204); border-right:1px solid rgb(204, 204, 204); padding:0in 5.4pt; width:51pt; height:12.75pt;' valign='bottom' width='68'>0</td><td style='border-left:1pt solid windowtext; border-right:none; padding:0in 5.4pt; width:48.9pt; border-top:none; border-bottom:1pt solid windowtext; height:12.75pt;' valign='bottom' width='65'>0</td><td style='border-left:none; border-right:none; padding:0in 5.4pt; width:48.9pt; border-top:none; border-image:initial; border-bottom:1pt solid windowtext; height:12.75pt;' valign='bottom' width='65'>.23</td><td style='border-left:1pt solid windowtext; border-right:none; padding:0in 5.4pt; width:49.3pt; border-top:none; border-bottom:1pt solid windowtext; height:12.75pt;' valign='bottom' width='66'>0</td><td style='border-left:none; border-right:none; padding:0in 5.4pt; width:38.5pt; border-top:none; border-image:initial; border-bottom:1pt solid windowtext; height:12.75pt;' valign='bottom' width='51'>1.00</td><td style='border-left:1pt solid windowtext; border-right:none; padding:0in 5.4pt; width:43.4pt; border-top:none; border-bottom:1pt solid windowtext; height:12.75pt;' valign='bottom' width='58'>0.00</td><td style='border-left:none; border-right:1pt solid windowtext; padding:0in 5.4pt; width:43.4pt; border-top:none; border-bottom:1pt solid windowtext; height:12.75pt;' valign='bottom' width='58'>0.1</td></tr></tbody></table>The Severity Index score for a section with no crashes will be 0For highway sections with recorded AADT count information. Traffic volume counts are not available for all sections of the state-maintained system. A large percentage of the secondary route system functionally classified as Local is not part of NCDOT’s count program. This accounts for almost 30,000 miles of the state system. For highway sections without traffic volume counts the following alternative scoring system will be used for the Critical Crash Rate Ratio Score: 1) a section with no crashes will receive a crash rate score of 0; 2) a section with at least one crash will receive a crash rate score of 33.7. The overall safety score is based on the weighted average of the crash density score, the severity index score, and the critical crash rate score. Segments à (Crash Density x 33%) + (Severity Index x 33%) + (Critical Crash Rate x 33%) Other notes:Routes having a mileposted crash percentage of 60% or lower were not scored. However, they are still represented on the map as a black line and have values of “NA” for the crash counts and scores. These are provided as an fyi so that the end user will know which sections were not scored due to crash mileposting issues. Sections of routes that have atypical cross sections (e.g. 3 through lanes with a continuous center turn lane) are not given a score because statewide average crash rates are not available for these cross sections.Crash Data DefinitionsCRASH DATA DEFINITIONS:Crash Density: Number of reported crashes per mile.Crash Severity: Crash severity is reported based on the “KABCO” scale. The crash injury status is the most severe injury to a person involved in the crash.K-Fatal. A death results from injuries within 12 months after the crash.A-Disabling. Prevents the person from performing normal activities for at least 24 hours.B- Evident. Obvious injury.C- Possible. No visible injury, may have momentary loss of consciousness.O- Property Damage Only (PDO).Critical Crash Rate: A statistically derived number, which is often used a screening tool to identify locations where crash rates are higher than should be expected for a given facility type and where further engineering investigations may be considered. To compute the critical crash rate for a site, use the following equation:Where:Fc= the critical crash rateFa= statewide average crash rate of roadway classK = a probability constant, as standard practice NCDOT uses K = 1.645 for a 95% confidence level.M = vehicle exposure (in 100 million vehicle-miles travelled or 100mvmt)Crash Rate: For a section of highway, the number of crashes per 100 million vehicle miles travelled.Crash Frequency: The number of reported crashes during a given timeframe.Severity Index: Locations with a high severity index have higher than average injury rates and/or more severe injuries. This index uses the reported “Crash Severity” (see definition above). The Transportation Mobility & Safety Division has established “Equivalent Property Damage Only” (EPDO) coefficients which are used to compare crash severity types among each other. One “B-injury” crash or “C-injury” crash is equivalent to 8.4 “PDO” crashes. One “K-injury” crash or “A-injury” crash is equivalent to 76.8 “PDO” crashes. The severity index of a location is equal to the total EPDO divided by the number of crashes.The North Carolina Department of Transportation shall not be held liable for any errors in this data. This includes errors of omission, commission, errors concerning the content of the data, and relative and positional accuracy of the data. This data cannot be construed to be a legal document. Primary sources from which this data was compiled must be consulted for verification of information contained in this data.<o:p></o:p>Brad Robinson, NCDOT Traffic Safety UnitSection safety scoring for lane departure crashes.Traffic SafetyNCNCDOTNorth CarolinaSection Scores