TFHRC Home > Safety > Safety Publications > FHWA-HRT-07-046 > Appendix B
| Generic Variable Description | Definition | MMIRE Priority12 | Ease of Data Collection 13 | |||||
|---|---|---|---|---|---|---|---|---|
| I. ROADWAY SEGMENT DESCRIPTORS | ||||||||
| I.a. Segment Location/Linkage Variables | ||||||||
| 1. County18 | County location of segment | 1 | E | M | B | |||
| 2. City/Local Jurisdiction | City/local jurisdiction location of segment if applicable | 1 | E | U | O | M | ||
| 3. Route Number | Route number | 1 | E | U | Y | M | M | |
| 4. Street Name | Street Name | 1 | E | |||||
| 5. Section End-Points Descriptors | Location information defining the location on a route of each endpoint of the section | 1 | E | U | Y | M | E | |
| 6. Section Identifier | Unique segment identifier, derived from other variables (e.g., combination of route number, county location and beginning and ending mileposts | 1 | E | U | M | E | ||
| 7. Section Length | Section Length | 1 | E | U | Y | M | ||
| 8. Highway District | Highway District | 1 | E | O | ||||
| 9. Governmental Ownership | Governmental owner of segment (including FIPS code) | 1 | E | U | ||||
| 10. Type of Governmental Ownership | Type of governmental ownership | 1 | ||||||
| 11. Route Signing | Type of route signing on the segment | 1 | E | U | M | M | ||
| 12. Route Signing Qualifier | Whether the route is "business" or other qualifier | 1 | E | U | ||||
| 13. Coinciding Route Indicator | Whether the route segment is a "primary" coinciding route (i.e., the route that crashes are referenced to) or a "minor" coinciding route | 1 | E | |||||
| 14. Coinciding-Route Primary Route Number | If a minor coinciding route segment, the route number for the major (primary) route | 1 | E | |||||
| 15. Direction of Inventory | Direction of Inventory | 1 | E | |||||
| I.b. Segment Roadway Classification | ||||||||
| 16. Functional Class | Functional class | 1 | E | U | M | M | YES | |
| 17. Rural/Urban Designation | Rural/Urban Designation | 1 | E | U | Y | M | B | |
| 18. Federal Aid/ Route Type | Federal Aid/ Route Type | 1 | E | U | E | |||
| 19. Access Control | Access Control | 1 | E | S | O | M | YES | |
| 20. Operational Class | Operational class of segment, if different from official functional class | 2 | D | |||||
| I.c. Segment Cross Section | ||||||||
| I.c.1. Surface Descriptors | ||||||||
| 21. Surface Type | Surface type (paved, unpaved or types of pavement) | 1 | E | S | Y | |||
| 22. Surface Friction | Surface friction indicator | 1 | D | |||||
| 23. Surface Friction Date | Date surface friction measured | 1 | ||||||
| 24. Total Surface Width | Total paved surface width (could be derived if all other lane widths are captured) | 2 | M | B | ||||
| 25. Pavement Roughness | Pavement roughness (roughness number) | 2 | D | U | E | |||
| 26. Pavement Roughness Date | Date pavement roughness number assigned | 2 | ||||||
| 27. Pavement Condition | Pavement condition (descriptive scale) | 2 | D | S | M | |||
| 28. Pavement Condition Date | Date pavement condition assigned | 2 | ||||||
| I.c.2. Lane Descriptors | ||||||||
| 29. No. of Thru Lanes | Number of thru lanes, including HOV and reversible lanes | 1 | E | U | Y | M | M | YES |
| 30. Average Thru Lane Width | Average lane width used by traffic (i.e., not including wide curb lanes, parking area, bicycle lanes, etc.) | 1 | M | S | Y | M | O | YES |
| 31. Exclusive Left Turn Lane Presence | Exclusive left turn lane type | 1 | E | |||||
| 32. Exclusive Left Turn Lane Length | Exclusive left turn lane length | 1 | E | |||||
| 33. Exclusive Right Turn Lane Presence | Exclusive right turn lane type | 1 | E | |||||
| 34. Exclusive Right Turn Lane Length | Exclusive right turn lane length | 1 | E | |||||
| 35. Auxiliary Lane Presence/Type | Presence or type of auxiliary lane | 1 | E | |||||
| 36. Auxiliary Lane Length | Length of auxiliary lane | 1 | E | |||||
| 37. HOV Lanes | Presence of HOV lanes in segment | 1 | M | U | M/O | |||
| 38. HOV Lane Types | HOV lane types | 2 | E | |||||
| 39. Reversible Lanes | Number of reversible lanes present on segment | 1 | ||||||
| 40. Presence/Type of Bicycle Facility | Presence or type of bicycle facility on segment | 1 | D | B | YES | |||
| 41. Width of Marked Bicycle Lane or Bike Path | Width of marked bicycle lane or bike path | 1 | D | |||||
| 42. Width of Wide Curb Lane | Width of wide curb lane used by both vehicles and bicycles | 1 | M | |||||
| 43. Number of Peak Hour Lanes | Number of through lanes used in peak period in the peak direction | 2 | M | U | ||||
| I.c.3. Shoulder Descriptors | ||||||||
| 44. Right Shoulder Type | Shoulder type on right side of road in direction of inventory | 1 | E | S | Y | M | M | |
| 45. Right Shoulder Total Width | Total width of right shoulder, including paved and unpaved parts | 1 | M | Y | O | B | YES | |
| 46. Right Paved Shoulder Width | Width of paved portion of right shoulder | 1 | E | S | Y | O | B | YES |
| 47. Left Shoulder Type | Shoulder type on left side of roadway in direction of inventory. For undivided roads and divided roads with one direction of inventory, this will be the outside shoulder on the opposing side. NOTE that information on paved width of the inner (left) shoulder on divided roads is captured in the Median descriptors. | 1 | E | S | Y | M | M | |
| 48. Left Shoulder Total Width | Width of left (outside) shoulder, including paved and unpaved parts | 1 | M | Y | O | B | YES | |
| 49. Left Paved Shoulder Width | Width of paved portion of left shoulder | 1 | E | S | Y | O | B | YES |
| 50. Shoulder Rumble Strip Presence | Presence of shoulder rumble strip | 1 | M | S | ||||
| 51. Rumble Strip Type | Rumble strip type if present | 2 | M | |||||
| 52. Sidewalk Presence | Presence of sidewalk in direction of inventory | 1 | D* | B | ||||
| 53. Curb Presence | Presence of curb | 1 | M | B | ||||
| 54. Curb Type | Curb type | 2 | D | |||||
| I.c.4. Median Descriptors | ||||||||
| 55. Median Type | Median type (including two-way left turn lane) | 1 | E | S | M | M | ||
| 56. Median Width | Median width, including inside shoulders | 1 | E | S | O | M | YES | |
| 57. Median Barrier Type | Median barrier type | 1 | E | M | ||||
| 58. Median (Inner) Paved Shoulder Width | Median (inner) paved shoulder width | 1 | E | |||||
| 59. Median Shoulder Rumble Strip Presence | Width of left (outside) shoulder, including paved and unpaved parts | 1 | M | |||||
| 60. Median Rumble Strip Type | Rumble strip type if present | 2 | M | |||||
| 61. Median Left Turn Lane Type | Type of left turn lane in median. | 1 | E | |||||
| 62. Median Left Turn Lane Width | Width of median left turn lane | 1 | E | |||||
| I.d. Segment Roadside Descriptors | ||||||||
| 63. Roadside Clearzone Width | Roadside clearzone width | 1 | D* | |||||
| 64. Sideslope | Sideslope | 1 | D* | |||||
| 65. Roadside Rating | A rating of the safety of the roadside from Appendix D, Publication No. FHWA-RD-99- 207, Prediction of the Expected Safety Performance of Rural Two-Lane Highways. Only collect if clearzone width and sideslope are not collected. | 1(only if clearzone and sideslope variables are not collected) | D | Y | ||||
| 66. Driveway Information | Driveway count by type | 1 | D* | Y | ||||
| 67. Roadside Hardware Descriptors | Roadside hardware descriptors (including type, location, size, distance from lane edge). Examples include barrier (type and terminal type), signs (size, breakaway?), culverts, etc. | 2 (Linkage to Asset Management ?) | D* | |||||
| I.e. Other Segment Descriptors | ||||||||
| 68. Terrain Type (e.g., Mountainous, Level) | Basic terrain type around segment. This is a (poor) surrogate for detailed data on curvature and grade, and would be collected only in the absence of those variables. See “Alignment” variables below. | 1 | M | S | O | B | ||
| 69. Bridge Descriptors for Bridges in Segment | Bridge descriptors for bridges in segment | Linkage to Bridge File | E | |||||
| 70. RR Grade Crossing Descriptors for Crossings in Segment | RR grade crossing descriptors for crossings in segment | Linkage to RR File | E | |||||
| 71. Number of Signalized Intersections in Section | Number of signalized intersections in section | 1 (only if no intersection file) | M* | S | ||||
| 72. Number of Stop-Controlled Intersections in Section | Number of stop-controlled intersections in section | 1 (only if no intersection file) | M* | S | ||||
| 73. Number of Uncontrolled/Other Intersections | Number of uncontrolled/other intersections | 1 (only if no intersection file) | M* | S | ||||
| 1.f. Segment Traffic Flow Data | ||||||||
| 74. Average Daily Traffic Volume | Average Annual Daily Traffic | 1 | E | U | Y | M | M | YES |
| 75. AADT Year | Year of AADT | 2 (if annual file) | E | Y | M | YES | ||
| 76. AADT Annual Escalation Percentage | AADT annual escalation percentage | 2 (if annual file) | M | O | O | B | ||
| 77. Percentage Truck or Truck AADT | Percentage truck or truck AADT (includes tractor-semis and trucks with 6+ wheels) | 1 | M | S | O | E | ||
| 78. Total Daily Two-Way Pedestrian Count/Exposure | Total daily pedestrian flow in both directions (unless directional segment). This is a (poor) surrogate for crossing pedestrian counts. | 2 (Collect only if crossing counts are unavailable for intersection/ junction approaches. see below) | D | |||||
| 79. Bicycle Count/Exposure | Total daily bicycle flow in both directions (unless directional segment) | 1 | D | S | ||||
| 80. Motorcycle Count or Percentage | Motorcycle daily count or percentage of AADT | 1 | D | |||||
| 81. Hourly Traffic Volumes (or Peak and Off-Peak AADT) | Hourly traffic volumes (or peak and off-peak AADT) |
2 | D | O | ||||
| 82. K-Factor | The K-factor is the 30th highest hourly volume (i.e., the design hour volume) for a year, as a percentage of the annual average daily traffic | 2 | D | S | B | |||
| 83. Future AADT | Forecasted AADT | 2 | D | U | O | B | ||
| 84. Future AADT Year | Year of forecasted AADT | 2 | D | U | O | B | ||
| 85. Directional Factor | Proportion of peak hour traffic in the predominate direction of flow | 2 | D | S | O | |||
| 86. Percent Combination Trucks - Daily Average | Percent combination trucks—daily average | 2 | M | S | E | |||
| 87. Percent Single Unit Trucks - Daily Average | Percent single unit trucks—daily average | 2 | M | S | E | |||
| 1.f. Segment Traffic Flow Data | ||||||||
| 88. One/Two-Way Operations | Whether the segment operates as a one- or two-way roadway | 1 | E | U | M | |||
| 89. Speed Limit | Speed Limit | 1 | E | U | O | M | ||
| 90. School Zone Indicator | Whether segment contains a school zone | 1 | M | |||||
| 91. On-Street Parking Presence | Time-based parking restrictions | 1 | D | S | M | |||
| 92. On-Street Parking Type | On-street parking type | 1 | D | S | ||||
| 93. Roadway Lighting | Type of roadway lighting | 1 | M | S | B | YES | ||
| 94. Truck Route Designation | Truck route designation | 1 | E | U | ||||
| 95. Toll Facility? | Toll facility indicator | 1 | E | U | ||||
| 96. Edgeline Presence/Type | Edgeline presence/type | 1 | D* | |||||
| 97. Centerline Presence/Type | Centerline presence/type | 1 | D* | |||||
| 98. No Passing Zone Code / Passing Permissibility | No passing zone code/passing permissibility | 2 | D* | S | ||||
| 99. 85th % Speed | Traffic speed exceeded by 15 percent of the vehicles in the flow | 2 | D | S | ||||
| II. Roadway Alignment Descriptors | ||||||||
| II.a. Horizontal Curve Data (NOTE: Each data record will define an angle point or a single curve, even if the curve is a component of a compound or reverse curve. Spirals or other transitions are part of the curve.) | ||||||||
| 100. Curve Identifiers and Linkage Variables | All variables needed to define location of each curve record and all variables necessary to link with other safety files | 1 | D* | Y | ||||
| 101. Curve Feature Type | Type of horizontal alignment feature being described in the data record | 1 | D* | |||||
| 102. Horizontal Curve Degree or Radius | Degree or radius of curve | 1 | D* | S | Y | S | YES | |
| 103. Horizontal Curve Length (Including Spiral) | Length of curve | 1 | D* | S | Y | S | E | YES |
| 104. Curve Superelevation or Superelevation Adequacy | Either measured superelevation rate or percent or adequacy of superelevation when compared to AASHTO design standards | 2 | D* | Y | YES | |||
| 105. Horizontal Transition/Spiral Curve Presence | Presence/type of transition from tangent to curve | 1 | D | Y | ||||
| 106. Horizontal Curve Intersection/Deflection Angle | The angle between the two intersecting tangents in the direction of inventory (sometimes called the "deflection angle") | 2 | D | |||||
| 107. Horizontal Curve Direction | Direction of curve in direction of inventory | 1 | M* | Y | S | |||
| II.b. Vertical Grade Data (NOTE: Each data record will define an individual grade or the angle point or vertical curve linking two grades.) | ||||||||
| 108. Grade Identifiers and Linkage Variables | All variables needed to define location of each vertical feature and all variables necessary to link with other safety files | 1 | E | |||||
| 109. Vertical Alignment Feature Type | Type of vertical alignment feature being described in the data record | 1 | E | |||||
| 110. Percent of Gradient | Percent of Gradient | 1 | D* | Y | S | E | YES | |
| 111. Grade Length | Grade Length | 1 | D* | S | Y | |||
| 112. Vertical Curve Length | Vertical Curve Length | 1 | D | |||||
| III. Roadway Junction Descriptors | ||||||||
| III.a. At-Grade Intersection/Junctions (NOTE: These junctions can include both normal "intersections" and also junctions of roadways with independent pedestrian crossings, bike trails, railroad grade crossings, etc. Thus, the category includes what has been considered "mid-block" crossings.) | ||||||||
| III.a.1. General Descriptors | ||||||||
| 113. Unique Intersection Identifier | A numeric unique identifier for each intersection/junction | 1 | E | |||||
| 114. Type of Intersection/Junction | Type of junction being described in the data record | 1 | E | |||||
| 115. Location Identifier for Road 1 Crossing Point | Location on the first intersecting route (e.g., route-milepost) | 1 | M | Y | B | |||
| 116. Location Identifier for Road 2 Crossing Point | Location on the second intersecting route (e.g., route-milepost) | 1 | D (unless spatial data system) | |||||
| 117. Location Identifier for Road 3, 4, etc., Crossing Point (e.g., Route-Milepost), etc. | Location on the third and subsequent intersecting route (e.g., route-milepost) | 1 | D (unless spatial data system) | Y | ||||
| 118. Intersection/Junction No. of Legs | Intersection/junction no. of legs | 1 | M | Y | M | |||
| 119. Intersection/Junction Geometry | Intersection/junction geometry | 1 | E | Y | M | |||
| 120. School Zone Indicator | Whether the intersection/junction is in a school zone | 1 | E | |||||
| 121. Railroad Crossing Number if a RR Grade Crossing | Railroad crossing number if a RR grade crossing (for linkage to National Highway-Rail Crossing Inventory) | 1 | M | |||||
| 122. Intersection Skew Angle | Angle from perpendicular of intersection of the roads | 1 | D | Y | S | |||
| 123. Intersection/Junction Offset | Whether crossroad approach centerlines are directly opposed or offset by some distance | 1 | D | O | E | |||
| 124. Intersection/Junction Offset Distance | Distance that approach centerlines are offset | 1 | D | O | M | |||
| 125. Intersection/Junction Traffic Control | Traffic control present at intersection/junction | 1 | M | Y | M | YES | ||
| 126. Signalization Type (e.g., Actuated, Fixed, System) | Type of signalization at intersection/junction | 2 | M | S | ||||
| 127. Number of Intersection/Junction Quadrants With Limited Sight Distance | Number of intersection/junction quadrants with limited sight distance | 1 | D | Y | B | |||
| 128. Intersection/Junction Lighting | Type of lighting at intersection/junction | 1 | M | |||||
| 129. Roundabout - No. of Circulatory Lanes | No. of circulatory lanes in roundabout | 1 | E | |||||
| 130. Roundabout - Circulatory Width | Width of the roadway between the central island and outer edge of the circulatory lane | 1 | E | |||||
| 131. Roundabout—Inscribed Diameter | Distance between the outer edges of the circulatory roadway | 1 | M | |||||
| 132. Roundabout—Bicycle Facility | Type of bicycle facility at roundabout | 1 | E | |||||
| III.a.2. At Grade Intersection/Junction Descriptors—Each Approach | ||||||||
| 133. Approach AADT | AADT on approach described | 1 | E (if system road), M (if nonsystem crossroad) | YES | ||||
| 134. Approach Use Type | Usage of approach | 1 | E | |||||
| 135. Approach Is Two-Way, One- Way | One-way or two-way flow on approach | 1 | E | M | ||||
| 136. No. of Thru Lanes | Total number of thru lanes on approach, both directions | 1 | E | |||||
| 137. No. of Exclusive Left Turn Lanes | Number of exclusive left turn lanes on approach | 1 | M | Y | M | M | ||
| 138. No. of Exclusive Right Turn Lanes | Number of exclusive right turn lanes on approach | 1 | M | Y | M | |||
| 139. Length of Exclusive Left Turn Lanes | Length of exclusive left turn lanes | 2 | M | |||||
| 140. Length of Exclusive Right Turn Lanes | Length of exclusive right turn lanes | 2 | M | |||||
| 141. Median Type at Intersection | Median type at intersection on approach | 1 | M | M | ||||
| 142. Approach Traffic Control | Traffic control present on approach | 1 | M | |||||
| 143. Left Turn Protection | Presence and time of left turn protection | 1 | D | O | ||||
| 144. Signal Progression | Signal progression on approach | 1 | D | S | E | |||
| 145. Crosswalk Presence/Type | Type of crosswalk | 1 | D | |||||
| 146. Pedestrian Signalization Type | Type of pedestrian signalization on approach | 1 | M | B | ||||
| 147. Pedestrian Signal Special Features | Special features for either pushbutton or recall pedestrian signals | 2 | M | |||||
| 148. Crossing Pedestrian Count/Exposure | Count or estimate of average daily pedestrian flow crossing this approach (Note: only applicable to approaches with vehicular traffic.) | 1 | D | S | ||||
| 149. Left/Right Turn Prohibitions | Left or right turn prohibitions on this approach | 1 | D | O | ||||
| 150. Left Turn Counts/Percent | Count or estimate of average daily left turns, or percent of total approach traffic turning left (Note: This could also be captured for peak-periods only or by hour of day.) | 2 | D | O | ||||
| 151. Right Turn Counts/Percent | Count or estimate of average daily right turns, or percent of total approach traffic turning right (Note: This could also be captured for peak-periods only or by hour of day.) | 2 | D | O | ||||
| 152. Transverse Rumble Strip Presence | Presence of transverse rumble strip on approach | 2 | D | |||||
| 153. Roundabout—Entry Width | Full width of entry where it meets the inscribed circle. Note that total width of the approach can be derived from totaling entry width, exit width and splitter island width. | 1 | E | |||||
| 154. Roundabout—Number of Entry Lanes | Number of entry lanes into roundabout on this approach | 1 | E | |||||
| 155. Roundabout—Entry Radius | Minimum radius of curvature of the curb on the right side of the entry | 2 | D | |||||
| 156. Roundabout—Exit Width | Full width of exit where it meets the inscribed circle. Note that total width of the approach can be derived from totaling entry width, exit width and splitter island width. | 1 | E | |||||
| 157. Roundabout—Number of Exit Lanes | Number of exit lanes from roundabout on this approach leg | 1 | E | |||||
| 158. Roundabout—Exit Radius | Minimum radius of curvature of the curb on the right side of the exit | 2 | D | |||||
| 159. Roundabout—Pedestrian Facility | Type of pedestrian crossing facility on this approach to roundabout | 1 | E | |||||
| 160. Roundabout—Crosswalk Location (Distance From Yield Line) | Location of marked pedestrian crosswalk relative to yield line | 1 | E | |||||
| 161. Roundabout—Splitter Island Width | Width of the splitter island separating entry and exit legs (measured at the inscribed circle) | 1 | E | |||||
| III.b. Interchange and Ramp Descriptors | ||||||||
| III.b.1. General Interchange Descriptors | ||||||||
| 162. Unique Interchange Identifier | A numeric unique identifier for each interchange | 1 | E | |||||
| 163. Location Identifier for Road 1 Crossing Point | Location on the first intersecting route (e.g., route-milepost) | 1 | M | |||||
| 164. Location Identifier for Road 2 Crossing Point | Location on the second intersecting route (e.g., route-milepost) | 1 | D (unless spatial data system) | |||||
| 165. Location Identifier for Road 3, 4, etc., Crossing Point, etc. | Location on the third and subsequent intersecting route (e.g., route-milepost) | 1 | D (unless spatial data system) | |||||
| 166. Interchange Type | Type of interchange | 1 | M | M | ||||
| 167. Interchange Lighting | Type of interchange lighting | 1 | M | |||||
| III.b.1. General Interchange Descriptors | ||||||||
| 168. Unique Ramp Identifier | An identifier for each ramp that is part of a given interchange | 1 | E | |||||
| 169. Ramp Length | Length of ramp | 1 | M | O | M | |||
| 170. Ramp No. of Lanes | Number of lanes on ramp | 1 | M | O | E | |||
| 171. Ramp AADT | AADT on ramp | 1 | M | |||||
| 172. Ramp Posted Speed Limit | The posted (not advisory) speed limit on the ramp | |||||||
| 173. Feature at Beginning Ramp Terminal | A ramp is described by a beginning and ending ramp terminal in the direction of inventory. This variable describes the type of feature intersecting with the ramp at the beginning terminal. | 1 | E | |||||
| 174. Ramp Descriptor at Beginning Ramp Terminal | Description of the beginning terminal of the ramp | 1 | M | M | ||||
| 175. Location Identifier For Roadway at Beginning Ramp Terminal | Location on the roadway at the beginning ramp terminal (e.g., route-milepost for that roadway) if the ramp connects with a roadway at that point. | 1 | E (if begin point is on a system roadway) | |||||
| 176. Roadway Traffic Flow Direction at Beginning Ramp Terminal | Ramps can intersect a roadway on either of two sides. This defines the side of the road intersected by the ramp. | 1 | E | |||||
| 177. Feature at Ending Ramp Terminal | A ramp is described by a beginning and ending ramp terminal in the direction of inventory. This variable describes the type of feature intersecting with the ramp at the ending terminal. | 1 | E | |||||
| 178. Ramp Descriptor at Ending Ramp Terminal | Description of the ending terminal of the ramp | 1 | M | M | ||||
| 179. Location Identifier for Roadway at Ending Ramp Terminal | Location on the roadway at the ending ramp terminal (e.g., route-milepost for that roadway) if the ramp connects with a roadway at that point | 1 | E (if end point is on a system roadway) | |||||
| 180. Roadway Traffic Flow Direction at Ending Ramp Terminal | Ramps can intersect a roadway on either of two sides. This defines the side of the road intersected by the ramp. | 1 | E | |||||
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FHWA-HRT-07-046