Roadside Database Coding Manual (2023)

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Roadside Database Coding Manual Copyright National Academy of Sciences. All rights reserved. 17 ROADSIDE TABLE

Roadside Database Coding Manual Copyright National Academy of Sciences. All rights reserved. 18 ROADSIDE FORM ROAD CROSSING TYPE Screen Name: Type of Road Crossing Data Table: Roadside Variable: CrossType Element Attributes: 1 Departure 2 Re-entry 3 Partial Departure Source: NASS/CDS or CISS technician report Remarks: The type of crossing of the vehicle should be recorded for each departure. 1. A departure occurs when the CG of the vehicle crosses the edge of the traveled way onto the roadside. If a vehicle departs the traveled way and enters the median from a divided roadway, this will be considered a point of departure if one of the conditions is satisfied: • The vehicle strikes an object in the median. • The vehicle’s final resting position is in the median. 2. A re-entry occurs when the CG of the vehicle crosses over the edge of the traveled way from the roadside. 3. A partial departure occurs when some plane of the vehicle crosses over the edge of the traveled way, but the CG does not. A Roadside Table needs to be made for each individual departure. If the vehicle departs on the same roadside multiple times, then multiple departures should be recorded.

Roadside Database Coding Manual Copyright National Academy of Sciences. All rights reserved. 19 ROADSIDE FORM NUMBER OF DEPARTURES Screen Name: Number of departures or re-entries that have occurred Data Table: Roadside Variable: NumDepart Element Attributes: 0–99 Integer number for how many departures have occurred Source: NASS/CDS or CISS technician report Remarks: When multiple departures occur, the count should be tallied here. Only integer numbers should be entered in this field. If a partial departure occurs, this should still be included in the count.

Roadside Database Coding Manual Copyright National Academy of Sciences. All rights reserved. 20 ROADSIDE FORM DEPARTURE LOCATION Screen Name: Departure or Re-entry Lateral Location Data Table: Roadside Variable: DepReLat Element Attributes: -99.9–99.9 Lateral distance from reference point to point of departure or re-entry Source: NASS/CDS or CISS technician report Remarks: The reference point is defined as the first point at which the CG crosses over the edge of the traveled way. The sign convention of right of the reference point as positive and left of the reference point as negative should always be followed. If a partial departure occurs and it is the only road departure event throughout the course of the crash, the departure location is defined as the location of the CG at the point of impact. The departure location should be used as the (0,0) reference point when taking measurements for the case reconstruction. If the first departure is a partial departure, but at a later time in the event, the CG crosses over the traveled way, the point of full departure should be used at the reference point. If only a partial departure occurs (i.e., the CG of the vehicle never crosses the edge of the traveled way, but one or more off road events occur), the reference point is defined as the first point of impact. A Roadside Table row needs to be made for each individual departure. If the vehicle departs on the same roadside multiple times, then make a table for that same roadside multiple times. Figure 6. Lateral departure or re-entry location.

Roadside Database Coding Manual Copyright National Academy of Sciences. All rights reserved. 21 ROADSIDE FORM DEPARTURE LOCATION Screen Name: Departure or Re-entry Longitudinal Location Data Table: Roadside Variable: DepReLong Element Attributes: -99.9–99.9 Longitudinal distance from reference point to point of departure or re- entry Source: NASS/CDS or CISS technician report Remarks: The longitudinal distance should be measured parallel to the edge of the traveled way from the reference point to the CG of the vehicle at the point of departure or re-entry. The reference point is defined as the first point at which the CG crosses over the edge of the traveled way. The sign convention of ahead of the reference point as positive and behind the reference point as negative should always be followed. If a partial departure occurs, the departure location is defined as the location of the CG at the point of impact. If the first departure is a partial departure, but at a later time in the event, the CG crosses over the traveled way, the point of full departure should be used as the reference point. If only a partial departures occur (i.e., the CG of the vehicle never crosses the edge of the traveled way, but one or more off road events occur), the reference point is defined as the first point of impact. A Roadside Table row needs to be made for each individual departure. If the vehicle departs on the same roadside multiple times then make a table for that same roadside multiple times. Figure 7. Longitudinal departure or re-entry location.

Roadside Database Coding Manual Copyright National Academy of Sciences. All rights reserved. 22 ROADSIDE FORM SIDE Screen Name: Select Side Data Table: Roadside Variable: Side Element Attributes: 1 Left 2 Right Source: NASS/CDS or CISS technician report Remarks: For roads divided by median, the Left Roadside is the side of the road adjacent to the median in the direction of travel of the vehicle. A Roadside Table row needs to be made for each individual departure. If the vehicle departs on the same roadside multiple times, then make a table row for that same roadside multiple times.

Roadside Database Coding Manual Copyright National Academy of Sciences. All rights reserved. 23 ROADSIDE FORM ROAD EDGE DESCRIPTORS ROADSIDE CROSS SECTION Screen Name: Roadside Cross Section Data Table: Roadside Variable: SideCrossSection Element Attributes: 1 Level 2 Uniform Downslope 3 Multiple Downslopes 4 V-Shaped 5 V-Shaped with Toe Region 6 V-Shaped with Single Leading Downslope 7 V-Shaped with Multiple Leading Downslopes 8 Wall/Mountainside 9 Multiple Upslopes 10 Curb 88 Other -999 Unknown Source: Researcher determined – primary source is the NASS/CDS or CISS technician report and scene photos. Remarks: See Table 3 on the next page for variable description diagrams. When assessing the roadside cross section, concrete barriers and curbs are included are counted as part of the roadway, but guardrails are not.

Roadside Database Coding Manual Copyright National Academy of Sciences. All rights reserved. 24 Table 3. Diagrams of roadside cross-section codes.

Roadside Database Coding Manual Copyright National Academy of Sciences. All rights reserved. 25 ROADSIDE FORM ROAD EDGE DESCRIPTORS RUMBLE STRIP Screen Name: Rumble Strip Present Data Table: Roadside Variable: Rumble Element Attributes: 0 No Rumble Strip 1 Rumble Strip -999 Unknown Source: Researcher determined – primary source is the NASS/CDS or CISS technician report and scene photos. Remarks: Records whether or not there is a rumble strip on the specified roadside where the departure or re- entry occurs. If the presence of a rumble strip cannot be determined due to snow coverage or an obscured view of the road, enter “-999.”

Roadside Database Coding Manual Copyright National Academy of Sciences. All rights reserved. 26 ROADSIDE FORM ROAD EDGE DESCRIPTORS SHOULDER SURFACE Screen Name: Shoulder Type Data Table: Roadside Variable: ShoulderType Element Attributes: 0 None 1 Asphalt (AC) 2 Concrete (Portland Cement Concrete Surface) 3 Stabilized (Gravel or other granular material) 4 Combination (2+ surface types exist) 5 Earth (Dirt or grassy) -999 Unknown Source: Researcher determined – primary source is the NASS/CDS or CISS technician report and scene photos. Remarks: This gives the shoulder surface type. Variable definitions are adapted from MIRE.

Roadside Database Coding Manual Copyright National Academy of Sciences. All rights reserved. 27 ROADSIDE FORM ROAD EDGE DESCRIPTORS SHOULDER WIDTH Screen Name: Shoulder Width Data Table: Roadside Variable: ShoulderWidth Element Attributes: 00.0–99.9 Width of shoulder in meters -999 Unknown Source: NASS/CDS or CISS Scene Diagram Remarks: The shoulder should be measured at the point of departure. For roads divided with a median, the left shoulder width is the distance between the end of the left-most lane in the direction of travel and the median. If no shoulder is present, enter “0.” If the width cannot be determined, enter “-999.”

Roadside Database Coding Manual Copyright National Academy of Sciences. All rights reserved. 28 ROAD FORM ROAD PROFILE DEPARTURE SPEED Screen Name: Departure Speed Data Table: Roadside Variable: DepSpeed Element Attributes: 00.0–900.0 Estimated speed at start of event (km/h) -999 Unknown Source: Crash reconstruction Remarks: The recorded speed should be in units of kilometers per hour.

Roadside Database Coding Manual Copyright National Academy of Sciences. All rights reserved. 29 ROAD FORM ROAD PROFILE DEPARTURE SPEED USING EDR Screen Name: Departure Speed using EDR Data Table: Roadside Variable: DepSpeedEDR Element Attributes: 00.0–900.0 Estimated speed at start of event (km/h) -999 Unknown Source: Crash reconstruction Remarks: The recorded speed should be in units of kilometers per hour.

Roadside Database Coding Manual Copyright National Academy of Sciences. All rights reserved. 30 ROADSIDE FORM DEPARTURE DESCRIPTORS DEPARTURE ANGLE Screen Name: Departure Angle Data Table: Road Variable: DepAngle Element Attributes: 00.0–359.9 Angle of vehicle CG travel at the point of departure with respect to tangent of roadway at point of departure Source: Crash Reconstruction Remarks: Departure angles between 0 and 180o indicate that the vehicle is departing on the right side of the roadway. Departure angles between 180.1o and 359.9o indicate that the vehicle is departing the road on the left side. NOTE: if a vehicle departs the traveled way and enters the median on a divided roadway, this will be considered a point of departure if one of the conditions is satisfied: 1. The vehicle strikes an object in the median. 2. The vehicle’s final resting position is in the median. Figure 8. Departure angle.

Roadside Database Coding Manual Copyright National Academy of Sciences. All rights reserved. 31 ROADSIDE FORM DEPARTURE DESCRIPTORS DEPARTURE HEADING Screen Name: Departure Heading Data Table: Roadside Variable: DepHeading Element Attributes: 00.0–359.9 Angle of vehicle heading at point of departure with respect to tangent of roadway at point of departure in degrees Source: Crash reconstruction Remarks: Heading angles between 0 and 180° indicate the vehicle is angled right with respect to the center line of the vehicle. Heading angles between 180.1° and 359.9° indicate the vehicle is angled left with respect to the center line of the vehicle. See diagram below. NOTE: if a vehicle departs the traveled way and enters the median on a divided roadway, this will be considered a point of departure if one of the conditions is satisfied: 1. The vehicle strikes an object in the median. 2. The vehicle’s final resting position is in the median. Figure 9. Departure heading. (+) 0°

Roadside Database Coding Manual Copyright National Academy of Sciences. All rights reserved. 32 ROADSIDE FORM ROAD EDGE DESCRIPTORS WIDTH OF UNOBSTRUCTED CLEAR AREA Screen Name: Clear Area Width Data Table: Road Variable: ClearWidth Element Attributes: 0–99.9 Clear area width in meters Source: NASS/CDS or CISS Scene Diagram Remarks: This is the distance from the edge of the traveled way to the nearest roadside object through the longitudinal distance the vehicle traveled. If a vehicle departs from multiple sides of the road, clear width must be measured for each side. This is illustrated in Figure 10. This variable is adapted from MIRE. Figure 10. Clear area width measurement.

Roadside Database Coding Manual Copyright National Academy of Sciences. All rights reserved. 33 ROADSIDE FORM ROAD EDGE DESCRIPTORS CURB TYPE Screen Name: Curb Type Data Table: Roadside Variable: CurbType Element Attributes: 0 None 1 Sloping (Mountable) 2 Vertical (Barrier) -999 Cannot be determined Source: Researcher determined – primary source is the NASS/CDS or CISS technician report and scene photos. Remarks: A sloping curb has a height of less than 4” when the slope leading to the curb is greater than 1:1 or has a height of less than 6” when the slope leading to the curb is less than this ratio. Vertical curbs have heights greater than those that define a sloping curb. These definitions were adapted from MIRE.

Roadside Database Coding Manual Copyright National Academy of Sciences. All rights reserved. 34 ROADSIDE FORM ROAD EDGE DESCRIPTORS CURB HEIGHT Screen Name: Curb Height Data Table: Roadside Variable: CurbHeight Element Attributes: 00.0–99.9 Height of curb in centimeters -999 Unknown Source: NASS/CDS or CISS Scene Diagram Remarks: The curb height should be measured from the road surface. If no curb is present, enter “0.” If the height cannot be determined, enter “-999.”

Roadside Database Coding Manual Copyright National Academy of Sciences. All rights reserved. 35 ROADSIDE FORM ROAD EDGE DESCRIPTORS PAVEMENT DROP-OFF TYPE Screen Name: Drop-off Type Data Table: Roadside Variable: PavementDropoffType Element Attributes: 0 No Drop-off 1 Primarily Vertical 2 Safety Shape -999 Cannot be determined Source: NASS/CDS or CISS Scene Diagram Remarks: This variable is used to determine if the pavement is elevated from the surrounding shoulder or ground. For example, this could occur due to multiple iterations of repaving or from implementation of a safety shape.

Roadside Database Coding Manual Copyright National Academy of Sciences. All rights reserved. 36 ROADSIDE FORM ROAD EDGE DESCRIPTORS PAVEMENT DROP-OFF HEIGHT Screen Name: Drop-off Height Data Table: Roadside Variable: PavementDropoffHeight Element Attributes: 00.0–99.9 Height of pavement drop-off in centimeters -999 None/unknown Source: NASS/CDS or CISS technician measurements Remarks: This variable gives the distance from the road surface to the surrounding surface if a drop-off is present. If there is no drop-off, enter 0. If the drop-off height is unknown, enter -999”

Roadside Database Coding Manual Copyright National Academy of Sciences. All rights reserved. 37 ROADSIDE FORM ROADSIDE SLOPE SOIL CONDITION Screen Name: Soil Condition Data Table: Roadside Variable: SoilCond Element Attributes: 1 Normal 2 Muddy/Waterlogged 3 Frozen -999 Unknown Source: NASS/CDS or CISS technician report Remarks: This variable describes the condition of the slopes in the cross section. Only conditions that the vehicle was exposed to should be recorded. For example, if the bottom of the V-shaped cross section is muddy, but the vehicle did not traverse that area, the soil condition should be recorded as normal.

Roadside Database Coding Manual Copyright National Academy of Sciences. All rights reserved. 38 ROADSIDE FORM ROAD EDGE DESCRIPTORS POINT OF DEPARTURE MARKINGS Screen Name: Point of Departure Markings Data Table: Roadside Variable: MarkingPOD Element Attributes: 0 No Marking 1 Single Solid White 2 Single Solid Yellow 3 Double Solid White 4 Double Solid Yellow 5 Single Dashed White 6 Single Dashed Yellow 7 Solid-Dashed Yellow, Dashed on Side of Travel 8 Solid-Dashed Yellow, Solid on Side of travel 9 Bott’s Dots 88 Other -999 Unknown Source: Researcher determined – primary source is the NASS/CDS or CISS technician report and scene photos. Remarks: This is the lane marking style at the point of departure. If there is no marking, this variable should be 0.

Roadside Database Coding Manual Copyright National Academy of Sciences. All rights reserved. 39 ROADSIDE FORM ROAD EDGE DESCRIPTORS PARKING LANE Screen Name: Parking Lane Data Table: Roadside Variable: ParkingLane Element Attributes: 0 None 1 Parking Lane Remarks: This variable should be 1 only when there is a physical parking lane or when there are multiple vehicles parked on the side. Parking on the side of residential roads should not be consider as a parking lane.

Roadside Database Coding Manual Copyright National Academy of Sciences. All rights reserved. 40 ROADSIDE FORM ROADSIDE SLOPE NUMBER OF SLOPES Screen Name: Number of Slopes Data Table: Roadside Variable: NumSlopes Element Attributes: 1–8 Number of slopes Source: NASS/CDS or CISS technician report and measurements Remarks: This is the number of slopes on the roadside for which measurements were taken. The number of slopes reported here should equal the number of slopes for which data are available. Level areas on the side of the road are also regarded as slopes and should be included in this count of slopes. This information is unavailable in the NCHRP 17-43 database for most cases.

Roadside Database Coding Manual Copyright National Academy of Sciences. All rights reserved. 41 ROADSIDE FORM ROADSIDE SLOPE SLOPE OFFSET (1–8) Screen Name: Slope [1–8]: Slope Offset Data Table: Roadside Variable: SlopeOffset[1–8] Element Attributes: 00.0–999.9 Slope offset from edge of traveled way in meters Source: NASS/CDS or CISS technician measurements Remarks: For each slope identified, record the horizontal distance from the edge of the traveled way to the beginning of the slope. All measurements should be made from the same point on the edge of the traveled way. This information is unavailable in the NCHRP 17-43 database for most cases.

Roadside Database Coding Manual Copyright National Academy of Sciences. All rights reserved. 42 ROADSIDE FORM ROADSIDE SLOPE SLOPE RATE (1–8) Screen Name: Slope [1–8]: Slope Rate Data Table: Roadside Variable: SlopeRate[1–8] Element Attributes: -999.9–999.9 Rate of slope Source: NASS/CDS or CISS technician measurements Remarks: The rate of the slope is positive if it is rising above the plane of the road and negative if it is falling below the plane of the road. This is a unitless element giving the ratio of the rise of the slope to the run of the slope. Slope rate is unavailable for most cases in the NCHRP 17-43 database since it is typically not measured in NASS/CDS and CISS.

Roadside Database Coding Manual Copyright National Academy of Sciences. All rights reserved. 43 ROADSIDE FORM ROADSIDE SLOPE SLOPE WIDTH (1–8) Screen Name: Slope [1–8]: Slope Width Data Table: Roadside Variable: SlopeWidth[1–8] Element Attributes: 00.0–999.9 Horizontal width of slope in meters Source: NASS/CDS or CISS technician measurements Remarks: This element records the horizontal width of the slope, not the length of the slope. Measurement should be made from the end of the previous slope to the beginning of the next slope or end of immediate roadside environment. This element is unavailable for most cases in the NCHRP 17-43 database since it is typically not measured in NASS/CDS and CISS. Figure 11. Slope width measurement.