J.3 NHTSA Veh Measurement Technique Guide.pdf

C6 C5 C4 C3 C2 C1

NHTSA

Field Crash Investigations

3/2023 Edition

Vehicle Measurement Techniques

U.S. Department of Transportation National Highway Traffic Safety Administration National Center for Statistics and Analysis Washington, DC 20590

NHTSA Field Crash Investigations

For NHTSA Field Crash Investigation use only – distribution not authorized.

1.0 INTRODUCTION

2.0 POINT-TO-POINT MEASURING TECHNIQUE

FIGURE 1: FREESPACE

FIGURE 2: BUMPER LEAD and TAPER, and SIDE BODY CURVATURE

FIGURE 3: LOCATING BUMPER CORNER

3.0 INPUT FOR THE RECONSTRUCTION PROGRAMS: L, C, and D DIMENSIONS ... 5

3.1 The Damage Length L Dimensions (Smash L)

FIGURE 4: L DIMENSIONS

3.2 The C Dimensions

FIGURE 5: FRONT C DIMENSIONS

FIGURE 6: SIDE C DIMENSIONS

3.3 The D Dimension

FIGURE 7: D DIMENSIONS

4.0 DOCUMENTATION OF END PLANE IMPACTS

4.1 Placement of Total Station

FIGURE 8: TOTAL STATION

4.2 Documentation of End Plane Crush Profile

FIGURE 9: DAMAGE PROFILE WITHIN OVERALL LENGTH

FIGURE 10: DAMAGE PROFILE BEYOND OVERALL LENGTH

4.3 End Plane Impacts: Exceptions to Standard Measurement Protocol

4.3.1 Crush Averaging for Underride Impacts

4.3.2 Corner Impact Protocol

4.3.3 EAD

4.3.4 Vertical Bumper Rotation

FIGURE 11: BUMPER ROTATION

4.3.5 Fiberglass or Nonsteel Bodied Vehicles

4.3.6 Missing Components

FIGURE 12: MEASUREMENT LOCATION - BUMPER FASCIA PARTIALLY OFF

FIGURE 13: FREESPACE - BUMPER FASCIA OFF

5.0 DOCUMENTATION OF VEHICLE SIDE IMPACTS

5.1.1 Identify the Field L

United States Department of Transportation National Highway Traffic Safety Administration National Center for Statistics and Analysis Washington, DC 20590

FIGURE 14: DEFLECTION POINTS

FIGURE 15: DEFLECTION POINT TO CENTER

FIGURE 16: DEFLECTION POINT TO CORNER

5.1.2 Documenting the Side Damage Profile

FIGURE 17: SIDE CRUSH PROFILE DOCUMENTATION

FIGURE 18: SIDE CRUSH PROFILE DOCUMENTATION WITH BOWING

5.3 Side Plane Impacts: Exceptions to Standard Measurement Protocol

5.3.1 Crush Averaging for Underride Damage

5.3.2 Fiberglass or Nonsteel Bodied Vehicles

5.3.3 Side Impact Resulting in Pocketing Damage

FIGURE 19: POCKETING DAMAGE

5.3.4 Side Impact Missing Component

5.4 Documentation of Side Impact Measurements

5.4.1 Direct Damage to Pillars

FIGURE 20: DIRECT DAMAGE TO PILLARS

5.4.2 Vertical Height of Sill

FIGURE 21: HEIGHT OF SILL

5.4.3 Door Sill Differential

FIGURE 22: DOOR SILL DIFFERENTIAL

5.4.4 Height of Maximum Crush

FIGURE 23: HEIGHT OF MAXIMUM CRUSH

6.0 Documentation of Vehicle Rollover or Non-Horizontal Damage

6.1 Side Plane

6.1.1 Side Plane Zones

FIGURE 24: SIDE PLANE ZONES

6.1.2 Side Plane Rollover Measurement

FIGURE 25: ROLLOVER SIDE MEASUREMENTS

6.2 Top Plane

6.2.1 Top Plane Zones

FIGURE 26: TOP PLANE ZONES

6.2.2 Top Plane Rollover Measurement

FIGURE 27: ROLLOVER TOP MEASUREMENTS

APPENDIX A SEVERE UNDERRIDE DAMAGE

APPENDIX B DOCUMENTING SHIFT/BOWING FOR CDC

APPENDIX C REQUIRED VEHICLE SKETCH MEASUREMENTS

VEHICLE MEASUREMENT TECHNIQUES

1.0 INTRODUCTION

This document was developed to provide a guideline for the collection of vehicle damage data coded in NHTSA Data Systems. This manual includes techniques for field vehicle damage data collection and instructions regarding the use of these measurements in the crash reconstruction program WinSMASH. The damage data described in this manual is used as an input to the damage algorithm of the WinSMASH program.

It is important that Technicians understand that they must provide data for the computer program in a format that will generate the most accurate results. Because there are a variety of crash types and configurations, the logic of the program must be considered when preparing the data for input.

The stiffness coefficients of the damage-based algorithm of WinSMASH are derived from staged collision data. The algorithm assumes homogeneous stiffness across the front, side and rear structure of the vehicle; therefore, determining whether the collision damage occurred at a structurally strong or weak area of the vehicle is beyond the capability of the program. In WinSMASH, the derived stiffness coefficients for the front and rear end planes are representative of the stiffness of the most rigid structures of the vehicle, i.e., the bumper level.

Therefore, in the end impacts the bumper level must be given the primary emphasis when obtaining the measurement.

The WinSMASH side plane stiffness coefficients are derived from US Federal Motor Vehicle Safety Standard (FMVSS) 214 side crash tests. In the side impact testing, the moving deformable barrier (MDB) directly engages the side sill (rocker panel) while impacting the passenger compartment door area at the door beam level. The side stiffness coefficients are derived from the measurements taken at the door beam level. As a result, for side plane impacts the best representation of the derived stiffness coefficients is roughly the mid door level, therefore, it must be given the primary emphasis when obtaining the measurement.

If the structure of the vehicle no longer reflects the stiffness coefficients due to significant deterioration or modification, the vehicle is not applicable to the program. When the most rigid structure (e.g., bumper/frame or side door beam) of the vehicle is not involved, such as in an extreme underride (see Appendix A), the stiffness coefficients are no longer valid, and the reconstruction programs should not be utilized. Since only one vehicle damage data set can be entered for each impact, emphasis is placed on the damage level at which the stiffness coefficients were determined (i.e., frame or bumper level on end plane damage and door beam level on side plane damage). Using these procedures as the rule, certain other types of impacts, which violate the basic WinSMASH assumptions, have been accepted by making adjustments to the damage measurement values.

The basis for field data collection is the point-to-point vehicle measurement technique. The measurements are obtained by measuring the residual crush and subtracting the bumper/body taper to obtain the resultant crush profile.

In NHTSAs investigation-based programs vehicle crush profiles/measurements are used in conjunction with Collision Deformation Classification (CDC), vehicle specifications, and stiffness ratings to provide inputs for the WinSMASH reconstruction program. WinSMASH generates Delta-V, or change in velocity, which is a good indicator of crash severity.

CDCs are assigned for every impact to a CISS-applicable vehicle involved in the crash and crush measurements are required for the most severe impact for each towed vehicle. Crush measurements are NOT required in some situations:

Impacts that are NOT the most severe impact to this vehicle in the crash o If unsure of most severe impact, multiple impacts may need to be measured

If there is NO deformation to the frame rail in sideswipe or corner impacts (S or E in CDC column 6).

If the vehicle rolls over during the crash sequence, vertical and lateral rollover measurements should be obtained. Only measure the crush for initial impact PRIOR to roll if it’s a significant impact and damage NOT masked by rollover damage.

For example, intersection crash where the passenger car impacts an SUV in driver’s door and the SUV tips one quarter turn and slides to rest.

When crush measurements are NOT required, damage information will be limited to: Direct Damage Width, Direct Damage Location, and approximate Max Crush Location/Extent.

Unknown should be entered for crush plane Category, Field L Location, Field L, Field L-D, Smash L, and Direct D.

2.0 POINT-TO-POINT MEASURING TECHNIQUE

Point-to-point measurement is defined as the actual distance a specific component moved within its damaged plane. Freespace is the area between the original (undamaged) surface of the vehicle and the reference line created by the maximum length and width of the vehicles body and/or bumper taper (See Figure 1). This freespace must be subtracted from the C measurements when measuring from the reference line to the damaged area. For side impacts, when measuring at the mid-door level within the “P” area, there is generally no freespace to deduct. If the area of maximum deformation is lower on the door (near the sill), then freespace would be deducted, due to the contour of the door. Similarly, (for front impacts) when measuring above the bumper to points on the vehicle's front end (grille or front edge of the hood or fenders), the above bumper freespace must be subtracted to obtain actual crush (See Figure 2). Freespace may be obtained from this vehicle, an exemplar vehicle, or a FARO model.

Above Bumper Freespace

FIGURE 1:

FREESPACE

FIGURE 2: BUMPER LEAD and TAPER, ABOVE BUMPER FREESPACE

Reference Line

Reference Line

Body Taper Freespace

Bumper Taper Freespace

Bumper Taper Freespace

Bumper Lead Freespace

Reference Line

Measured Crush

2.1 Defining Bumper Corner (Apex)

A bumper corner, sometimes referred to as an apex, is the location where vehicle end planes and side planes meet; it defines the front, back, left and right planes of the vehicle. The distance from one end plane bumper corner to the other is referred to as the Undeformed End Width (UEW). The contoured design of vehicles makes it necessary to project the geometrical corner to the surface of the vehicle.

It is important to determine bumper corner locations in an accurate and practical way during field inspections. The contoured design of some vehicles allows bumper corners to simply be identified visually. For vehicles where the corner is not apparent, use the following process to locate the bumper corner:

1. Extend the front and side planes in straight lines as illustrated by the dashed lines in Figure 3. To extend vehicle planes, create straight lines by using pocket rods, tape measures, or a combination.

2. At the point where the extended lines intersect, project a 45° line to the bumper surface as illustrated by the solid line.

3. The point at which the 45° projection meets the bumper surface is the location of the bumper corner.

4. If the bumper cover is off, the outermost point of the bumper support is the location of the bumper corner.

FIGURE 3: Locating Bumper Corner

RF

Bumper Corner LF

Bumper Corner

3.0 INPUT FOR THE RECONSTRUCTION PROGRAM: L, C, and D DIMENSIONS

In order to describe the vehicle damage profile to the reconstruction program, the length (L), depth (Cs), and the location (D) of the damage must be documented. These dimensions are defined in the following paragraphs.

3.1 The Damage Length L Dimensions (Smash L)

The Damage Length is required as an input to WinSMASH program. It could be Field L or the Undeformed End Width (UEW). The Field L is the length of the direct and induced damage (restricted to the initial plane of contact, end, or side) measured parallel to the lateral axis for end and longitudinal axis for side damage. The UEW is the distance on an undamaged end plane measured corner to corner. It is important to follow the same damage length measurement protocol that is used in the stiffness coefficient calculations for WinSMASH.

On end plane impacts, the Field L is defined as the entire width of the end plane (i.e., corner to corner), use the UEW for the damage length in WinSMASH

On side plane impacts, enter the Field L for the Damage Length in WinSMASH. The length should include the entire direct and induced damage pattern, minus remote buckling

UEW = SMASH L

FIGURE 4:

L DIMENSIONS

3.2 The C Dimensions

The C dimensions are crush depth measurements taken at specific points along the Field L to report the damage depth of the crush profile. The crush measurements are defined every 10 cm along the Field L and must include the maximum crush. Once the crush measurements have been captured with the total station and downloaded into WinSMASH, the software takes all the measured crush points and converts them into six C measures for use in the WinSMASH program. See Figures 5 and 6.

Only one set of Cs can be entered into the program, although measurements at additional planes may be required for averaging. The crush profile entered must be the best representation of the structural damage to the vehicle. For additional information on obtaining C measurements, refer to the end and side plane damage documentation procedures discussed in Section 4.

3.3 The Damage Offset (D) Dimension

There are two “D” dimensions used in WinSMASH. They can be either positive or negative values. The Direct Damage D dimension (Direct +/- D) is the distance from the center of the direct damage width to the vehicle's damaged end plane center or the damaged wheelbase center. The center is represented by the CG symbol in Figure 7a, b, c. The Direct Damage length is measured along the general slope of the damaged plane (do not bend the tape measure).

The Field L D dimension (Field L +/- D) is the distance from the center of the Field L (direct and induced damage) to the vehicle’s damaged end plane center or the damaged wheelbase center, measured parallel to the damaged plane. On end impacts, it is calculated using the vehicle’s damaged centerline (i.e., damaged or shifted center point on the end plane).

For side impacts, use the midpoint of the damaged wheelbase. The Direct +/- D is illustrated in Figure 7a, b, and c. The Field L +/- D is illustrated in figure 7a and is smaller than the Direct +/- D since the Field L extends further forward than the direct damage. In Figure 7b and c the Field L +/- D is zero, since the Field L extends across the entire front end, while the Direct +/- D is as illustrated. Field L-D will always be zero on end plane impacts.

The Direct Damage D and Field L D values are automatically calculated in CISSWEB using the damage lengths, damage locations, and damage direction descriptions.

Direct +/- D

FIGURE 7:

D DIMENSIONS

FLd

Center Damaged

Wheelbase

Field L +/- D

Field L center

Direct center a b c

Field L

4.0 DOCUMENTATION OF VEHICLE END PLANE IMPACTS (FRONT OR REAR)

4.1 Placement of Total Station

The total station is assembled, and a new job is created using the protocols from the Total Station Setup Guidelines. The device should be placed in a location such that there is a clear point of sight to the crush that will be documented.

FIGURE 8:

Total Station

4.2 Documentation of the Damaged End Plane Crush Profile

For end plane impacts, the Field L, (i.e., length of the damaged area including direct and induced damage), does not extend laterally beyond the bumper corners. In other words, end plane crush should only be measured to vehicle components that were originally on the end plane of the vehicle. Once the total station has been set up, the crush profile should be documented using steps a-m below. If circumstances prohibit total station set up, refer to Appendix C.

a. On the end plane of a vehicle, the first measurement (C1) is defined as the left (driver’s perspective) bumper corner (fascia) or end of re-bar. Place numbered (C1) orange visual marker at this point.

b. The last measurement (Cn) is defined as the right (driver’s perspective) bumper

(fascia) or end of re-bar. Place an orange visual marker at this point.

Note: when there is an end plane impact the first measurement (C1) will be the left bumper corner and last measurement (Cn) will be the right bumper corner.

c. Measure the distance between the (C1 and Cn) parallel to the damaged plane using a tape measure and record the distance as the Field L. Do not bend the tape measure when obtaining the Field L measurement.

d. Place numbered orange visual markers along the Field L at 10cm increments.

e. The maximum crush (Cmax) point should be identified for photographic purposes by placing a single red visual marker above one of the orange C markers. Max crush should always be identified at one of the orange C markers. Minor adjustments to the orange C markers may be necessary to ensure max crush is captured.

f. Using a tape measure the location of the Field L and Direct Damage, with respect to the post-crash center point of the end plane. For example:

4cm right of center point extending right

Measure the Direct Damage length along the general slope of the damaged plane (do not bend the tape measure). The Direct Damage should be identified for photographic purposes using green visual markers. Direct Damage does not have to be located at one of the orange C markers, however, if it is in the same location place the green visual marker below the orange C marker.

g. The Direct Damage D and Field L D values are automatically calculated using the damage lengths, damage locations, and damage direction descriptions. The location of the maximum crush is computed in WinSMASH software from the profile measured using total station.

h. Identify any shifting of the frame rails and/or corners of the vehicle. See Appendix

B.

i. Assemble the total station using the Total Station Setup Guidelines.

j. Measure each of the crush points in order (from driver side to passenger side) using the total station. The measurements should always be taken at the structure (bumper) level and along the level of the most structural component when above bumper measurements are required (see 4.3.1 Crush Averaging).

k. Using the total station document the location of all the axles (RF, LF, RR, LR).

Next, document the center of the rear plane for frontal impacts (RCP), or center of the front plane for rear impacts (FCP). The prism pole and reflector will be required to obtain the points. These reference points, which help identify the overall length and wheelbase, will be used to align the vehicle damage in WinSMASH software. In situations where after-market equipment has been added (i.e., hitch, brush guard, or non-standard bumper), the rear or front center point may need to be obtained from an alternate location. Examples include moving rear center point a few centimeters left or right or identifying the overall length using other components of the vehicle. Make sure to annotate all the reference points which were in the damage area and moved due to crash forces and are not representative of vehicle’s actual dimensions. These points are deselected/not used in WinSMASH software for automatic alignment. It is important that these reference points are measured carefully and accurately by placing prism pole as close to the location as possible.

l. Using the damaged vehicle, an exemplar vehicle, or a scaled FARO model of the vehicle, measure the freespace (i.e., bumper taper and/or EAD foam) at the approximate C1-C6 positions. Use case notes if additional description of freespace location or measurements is necessary.

m. After the crush, axles, and centerline points have been obtained with the total station, save the file following the Total Station Download Protocols. The vehicle total station file will be used in WinSMASH software to generate six crush (C) values and location of Max Crush from all the measured points after freespace values have been entered. See instructions on WinSMASH software.

Note: If there is no deformation to the frame rail, crush profile measurements are not required for sideswipe or corner impacts (S or E in CDC column 6). Direct damage length, direct damage location, and max crush location should still be entered.

If one of the frame rails is deformed, then all crush profile measurements are required.

Figure 9 represents the result of this procedure for vehicles with a damage profile within the confines of the original overall length. In Figure 10, the right bumper corner (C6) extends beyond the original overall length.

When the actual point on the vehicle has been moved outward, such as in an offset frontal impact where the non-contacted side of the bumper rotates outward beyond the original overall length, the measurement is negative since it moved out from its original position rather than crushed in. Since WinSMASH does not allow negative values for crush, zero is entered at these locations. In Figure 10, the resultant crush would be zero (0) at C5 and C6. In situations where the bumper was snagged and pulled outward during separation or during a subsequent impact, you would ignore that portion of the bumper affected by the snagging and measure to a representative crush plane either behind or above the bumper.

C1=CMAX C6

C6 C1

Field L Field L

C4 C5 C5 C2 C2 C3 C3 C4

CMAX

FIGURE 9: DAMAGE

PROFILE WITHIN

OVERALL LENGTH

FIGURE 10: DAMAGE

PROFILE BEYOND

OVERALL LENGTH

4.3 End Plane Impacts: Exceptions to Standard Measurement Protocol

If there is no deformation to the frame rail in sideswipe or corner impacts (S or E in CDC column 6).

When crush measurements are NOT required, damage information will be limited to: Direct Damage Width, Direct Damage Location, and approximate Max Crush Location/Extent. The maximum crush location is measured with respect to vehicle’s damaged end plane center (e.g.

40cm left/right of center). Unknown should be entered for crush plane Category, Field L Location, Field L, Field L-D, Smash L, and Direct D.

4.3.1 Crush Averaging for Underride Impacts

An underride impact will result in uneven crush patterns between the bumper level and above bumper level. The following protocol is used when underride crush profiles are encountered. An adjustment to crush will be made only when there is above bumper crush that exceeds bumper level crush by 13 cm or more.

In most cases, two sets of measurements of the end plane will be required. The above bumper measurements should be taken to the radiator or radiator support. If the grill and fender crush slopes rearward (i.e., it is not vertical), measure to the mid-line. As a rule, never measure to the hood edge, unless the hood is jammed shut and there is no other option.

Set up the total station and measure at both the bumper level and above bumper level.

First measure all points (C1 - Cn) at bumper level including maximum, label each point as ‘C’.

Then measure all points at above bumper level, label each point as CU. Finally measure reference points RF, RR, LF, LR, RCP and FCP. The reference points are measured only once in the file. There will usually be a difference between the Field L measured at the bumper level and at the above bumper level. Enter the bumper level Field L when entering the measurements into the CISSWEB application.

The WinSMASH software will generate six crush (C1 – C6) values and location of maximum crush at each level based on all the measured points. After you enter the freespace for each level of measure, if the above bumper crush exceeds the bumper crush by 13 cm or more at any specific C location, the WinSMASH software will average the crush values at those locations.

Crush averaging is allowable at any number of C locations, provided the 13 cm or more variation exists. Note that the averaged value is used only for reconstruction programs. When the crush variation is less than 13 cm at a specific C location, the reconstruction software uses the bumper level crush. This applies even though the bumper level C measurement may equal zero. The following flow chart provides guidance in determining the applicability of crush averaging.

Notes:

Bumper level measures are not required when no apparent crush is present in front or rear override/underride impacts. Only measure the above bumper crush, label the points CU.

If the front bumper is missing or removed and there is no deformation to the frame rails, only capture the CU measurements for the above bumper level deformation.

If no stiff frontal component is available at the above bumper level (i.e., missing radiator support, no stiff hood edge), then no crush measurements are required.

In rear override/underride impacts above bumper level crush measurements (CU) should be taken at the visual maximum crush level. In many cases, for the above bumper damage, this will require measuring to the lower trunk body lid (striker is mounted to this body component).

4.3.2 Corner Impact Protocol

A corner impact: (i.e., 12FREE (41 cm or less) with frame deformation requires a crush profile to be documented. Note: Surface scratching is not considered “deformation”. If a sideswipe occurs at the corner (i.e., initiating at the leading foremost section of the fender), but the frontal plane is not engaged, no crush profile would be required, if there was no deformation to the frame (i.e., 01RYAS02). If it is uncertain as to whether it is a front or a side plane impact (with frame deformation), then both planes should be measured. If there is 41 cm or less with no frame deformation, then no crush profile is required.

Note: The width of direct contact damage will need to be visually represented, photographically with a reference scale. For corner impacts where the bumper fascia is intact; measure direct contact along the damaged plane and utilize the undamaged, opposite side of the bumper to assist with determining the exact bumper corner location.

4.3.3 Energy Absorbing Device

When an EAD (such as a Styrofoam or plastic honeycomb insert) is undamaged and displaced in the crash, it needs to be accounted for in the crush measurements. If it cannot be reasonably put back into place, the thickness of the EAD (bumper lead) is measured and subtracted from the crush as a separate line of freespace – do not combine it with the contour freespace (bumper taper).

If the EAD material is not available during the inspection, a freespace estimate of 5cm for EAD thickness should be deducted at each C-measure.

4.3.4 Vertical Bumper Rotation

If the bumper is rotated or twisted by the impact forces, an error in crush measurement of 3cm to 10cm can occur, depending on the degree of rotation and the size of the bumper. Crush measurements should be taken at the top or bottom of the bumper face whenever this situation exists with an adjustment row added to the crush profile. Figure 11 illustrates these situations.

Figure 11: BUMPER ROTATION

4.3.5 Fiberglass or Non-Steel Bodied Vehicles

The reconstruction program may be applicable to end plane impacts of non-steel bodied vehicles provided the maximum crush is at the bumper/frame area and an appropriate crush profile can be measured to a substantial structure. In most cases this may involve measuring to the steel reinforcement bar behind a plastic bumper (i.e., front of a Corvette). In this type of situation, free space will be significant and must be taken into account. If a representative crush profile cannot be obtained, measurements sufficient to encode a CDC (contact damage width and location, maximum crush) are required.

4.3.6 Missing Components

If the plastic bumper fascia is available but no longer attached to the vehicle, C-measures should be taken to the bumper support. Direct damage length should still be measured on the bumper fascia.

If the bumper fascia is partially off, measure to the 45-degree corner on the “known” bumper cover side and to the bumper support on the “missing” corner. See Figure 12. In this situation, the Field L should still be described as bumper corner to bumper corner with a Field L- D of zero.

Figure 12: Measurement Location - Bumper Fascia

Partially Off

When C-measures are taken at the bumper support (plastic bumper fascia missing), taper freespace measures should be taken at the C-measure location and not at the 45-degree corner.

No crush profile is required if plastic bumper fascia and metal bumper support are missing and there is no indication of frame rail deformation. If possible, locate direct contact damage and measure length for CDC purposes.

When the plastic bumper fascia and metal bumper support are missing and frame rail deformation is present, then two C-measures should be taken at the frame rail ends (i.e., C1 at front left frame rail and C2 at the front right frame rail end)

Figure 13: Freespace – Bumper Fascia Off

5.0 DOCUMENTATION OF VEHICLE SIDE IMPACTS

5.1 Documentation of the Vehicle Side Plane Crush Profile

5.1.1 Identify the Field L

When measuring side damage, the length of the damaged area is the Field L. When the damage does not include the corner of the side plane of the vehicle, the Field L is identified by deflection points, which form a "yoke" in the vehicle profile (See Figure 14 and Figure 15). The yoke can generally be identified by sighting along the body side profile from each end of the vehicle and observing where the damage area departs from the original body contour. Note that this body contour may not be a straight line or plane. In addition, minor contact damage such as surface scratches outside of the deflection points are ignored when identifying the damage yoke, however, surface scratches from the same impact are included when determining the direct damage for CDC.

Figure 14: Deflection Points

Side damage profiles may extend to/from a corner to a deflection point. In this situation, the Field L would be documented from the deflection point to the vehicle corner as illustrated in Figure 16. If the Field L does not include a corner and the crush measurements are taken near vertical mid door level the freespace will typically be zero. When measuring at the mid-door level within the “P” area, there is generally no freespace to deduct. If the area of maximum deformation is lower on the door (near the sill), then freespace would be deducted, due to the contour of the door. If the Field L includes a corner of the vehicle or if the crush measurements are taken at the sill or beltline levels, then freespace should be collected.

Figure 15: Deflection Points

Figure 16: Deflection Point to Corner

5.1.2 Documenting the Side Damage Profile

The total station is assembled, and a new job is created using the protocols from the Total Station Setup Guidelines. The device should be placed in a location such that there is clear point of sight to the crush that will be documented. Identify the Field L, then document the side damage using steps a-m below. If circumstances prohibit total station set up, refer to Appendix C.

a. On side planes, the first measurement (C1) is the rear most deflection point or damage end point. Locate C1 and place numbered orange visual marker at this point.

b. The last measurement (Cn) is the forward most deflection point or damage end point.

Locate Cn and place numbered orange visual marker at this point.

c. Measure the distance between C1 and Cn parallel to the damaged plane using a tape measure and record the distance as the Field L. Do not bend the tape measure when obtaining the Field L measurement.

d. The crush should be measured at the level best representing maximum crush, maintaining proximity to, or involvement of, structural components. Place numbered orange visual markers along the Field L at 10cm increments.

e. The maximum crush (Cmax) point should be identified for photographic purposes by placing a single red visual marker above one of the orange C markers. Max crush should always be identified at one of the orange C markers. Minor adjustments to the orange C markers may be necessary to ensure max crush is captured

f. Using a tape measure describe the location of the Field L and Direct Damage with respect to an axle (undamaged axle if possible). For example:

48 cm rearward of rear axle extending forward

Measure the Direct Damage length along and parallel to the damaged plane (do not bend the tape measure). The Direct Damage should be identified for photographic purposes using green visual markers. Direct Damage does not have to located at one of the orange C markers, however, if it is in the same location place the green visual marker below the orange C marker.

g. The Direct Damage D and Field L D values are automatically calculated using the damage lengths, damage locations, and damage direction descriptions. The location of the maximum crush is computed in WinSMASH software.

h. Identify any shifting/bowing of the vehicle. See Appendix B.

i. Assemble the total station using the Total Station Setup Guidelines.

j. Measure each of the crush points in order starting from the rear and moving forward using the total station. Label each point as C. If there is hinge, latch, or pillar failure (complete separation), which allows the side surface to crush further, and there is a 13 cm or more difference between the sill level and the maximum crush level at any point, measure both levels of crush according to the protocol described in section 5.3.1.

k. Using the total station document the location of all the axles (RF, LF, RR, LR). Next, document the center of the front and rear plane (FCP and RCP). The prism pole and reflector will be required to obtain some of the points. These reference points, which help identify the overall length and wheelbase, will be used to align the vehicle damage in WinSMASH. In situations where after-market equipment has been added (i.e., hitch, brush guard, or non-standard bumper) then the rear or front center point may need to be obtained from an alternate location. Examples include moving rear center point a few centimeters left or right or identifying the overall length using other components of the vehicle. Make sure to annotate all the reference points which were in the damage area and moved due to crash forces and are not representative of vehicle’s actual dimensions. These points are deselected/not used in WinSMASH software for automatic alignment. It is important that these reference points are measured carefully and accurately by placing prism pole as close to the location as possible.

l. If the Field L includes a corner of the vehicle or if the crush measurements are taken at the sill or beltline levels, then freespace should be collected. If the Field L does not include a corner and the crush measurements are taken near vertical mid door level, freespace will typically be zero. Using the damaged vehicle, an exemplar vehicle, or a scaled FARO model of the vehicle, measure the freespace at the approximate C positions. Use case notes if additional description of freespace location or measurements is necessary.

m. After the crush, axles, and centerline points have been obtained with the total station, save the file following the Total Station Download Protocols. The vehicle total station file will be used in WinSMASH software to generate six crush (C) values and location of Max Crush from all the measured points after freespace values have been entered. See instructions on WinSMASH software.

The procedure for handling the severely bowed vehicle is the same as in Figure 15. This method automatically includes the bowing in the crush measurements. Figure 18 represents the result of this procedure using steps a-m in Section 5.1.2 above.

FIGURE 18: SIDE

CRUSH

DOCUMENTATION

WITH

BOWING

FIGURE 17:

SIDE CRUSH

DOCUMENTATION

5.3 Side Plane Impacts: Exceptions to Standard Measurement Protocol

If there is NO deformation to the frame rail in sideswipe or corner impacts (S or E in CDC column 6).

If the vehicle rolls over during the crash sequence, vertical and lateral rollover measurements should be obtained. Only measure the crush for initial impact PRIOR to roll if it’s a significant impact and damage NOT masked by rollover damage.

For example, intersection crash where the passenger car impacts an SUV in driver’s door and the SUV tips one quarter turn and slides to rest.

When crush measurements are NOT required, damage information will be limited to: Direct Damage Width, Direct Damage Location, and approximate Max Crush Location/Extent. The maximum crush location is measured from the center of the damaged wheelbase for side plane impact (i.e., 50cm forward/rearward of center). Unknown should be entered for crush plane Category, Field L Location, Field L, Field L-D, Smash L, and Direct D.

5.3.1 Crush Averaging for Underride Damage

An underride impact will result in uneven crush patterns between the sill and door panels above the sill. The following protocol is used when side underride crush profiles are encountered.

An adjustment to crush will be made only when there is complete latch, pillar, or hinge failure/separation, which allows the surface to crush further than normal. An adjustment to crush will be made only when there is a 13 cm or greater difference between the sill and maximum crush level.

When this occurs, measure the maximum crush level first; label each point as C. Then measure all points at sill level including maximum; label each point as CU. Finally shoot the reference points RF, RR, LF, LR, RCP and FCP. The reference points are measured only once in the file. Like end plane override/underride impacts, the Field L length may vary at the sill level and the above sill maximum crush level. The Field L at the maximum crush level should be used in CISSWEB.

After the crush, axles, and centerline points have been obtained with the total station, save the file following the Total Station Download Protocols. The vehicle total station file will be used in WinSMASH software to generate six crush (C) values and location of Max Crush from all the measured points after freespace values have been entered. After you enter the freespace for each level of measure, if there is a 13 cm or greater difference between the sill and maximum crush levels (even if the sill measurement equals zero) at any specific location, the WinSMASH software will average the crush values at those locations. Crush averaging is allowable at any number of C locations, provided the 13 cm or more variation exists. Note that the average values are used only for reconstruction program. When the crush variation is less than 13 cm at a specific location, the reconstruction software uses the maximum crush value at that location.

The following flow chart will provide guidance in determining the applicability of crush averaging.

5.3.2 Fiberglass or Non-Steel Bodied Vehicles

Reconstruction programs may be applicable to side plane impacts of non-steel bodied vehicles provided the maximum crush is at the sill/frame area or the pillars and door beam area.

An appropriate crush profile can be measured to a substantial structure. In most cases this may involve measuring to the steel reinforcement beam behind a plastic door or sill. In this type of situation, free space will be significant and must be taken into account.

5.3.3 Side Impact Resulting in Pocketing Damage

The Field L in Figure 19 is measured to the point of greatest pocketing. The C1 measurement is the perpendicular distance between the reference line and the point of greatest pocketing. The point of greatest pocketing is not necessarily the point of maximum lateral penetration.

FIGURE 19: POCKETING DAMAGE

5.3.4 Missing Components

When a damaged structural component is partially or completely missing, measure the point(s) on the remains of the crushed components. Measure only the start and end point of missing part/component. If a door with maximum crush is missing, determine the Field L on the pillars and measure the points on the pillars to which the door was attached to. If the sill has more damage than the door, measure along the sill.

5.4 Documentation of Side Impact Measurements

When a vehicle sustains left or right damage that meets the side impact measurement criteria, and requires crush measurements, the following protocols should be used to collect:

Direct Damage to Pillars, Vertical Sill Height, Height of Door Max Crush, and the Door Sill Differential. These measurements are taken for the vehicle with side plane damage when all of the following conditions are met:

1. Vehicle to vehicle impact

2. Frontal plane to side plane impact

3. CDC column 4 equals D, P, Y, or Z

4. Max crush is to the P zone

5.4.1 Direct Damage to Pillars

All pillars that sustained direct damage from the striking vehicle are identified. In Figure 20, the B and C pillars would be positively indicated. The damage to the A pillar is induced damage rather than direct damage and would not be included. Note: Direct damage to a pillar includes damage to the door panel edge that is overlying the pillar.

5.4.2 Vertical Height of Sill

The vertical height of the sill is measured from the ground to the sill where it meets the door seam. This value is a precrash measurement and can be taken from the undamaged side of the inspected vehicle or an exemplary vehicle (Figure 21). If the tires on the vehicle are flat, the height of the flattened side wall should be added to the measurement. However, if the vehicle is modified (certified or not) exemplar vehicles or manufacturer specifications should not be used.

Sill height

FIGURE 20:

DIRECT DAMAGE

TO PILLARS

FIGURE 21:

EXEMPLARY

VEHICLE

HEIGHT

OF SILL

5.4.3 Door Sill Differential

The door sill differential is the post-crash lateral distance between the damaged sill and the maximum crush point at the door level. After the crush measurements have been taken and the maximum crush point has been determined, select the point on the sill that is aligned vertically with the location of max crush to determine the door sill differential (DSD). Frontal components on the vehicle in Figure 22 have been removed to provide a cut-away view of this measurement.

1. A pocket rod or tape measure is positioned vertically on the outside of the sill at a point aligned with the max crush of the door. This is a damaged measurement, so use the identified point whether or not there is damage to the sill at that location.

2. A second pocket rod is placed laterally at a right angle to the vertical rod.

3. The lateral rod is moved toward the vehicle until it makes contact at the point of max crush.

4. The measurement from the damaged door surface to the vertical rod is recorded as the door sill differential.

5.4.4 Height of Maximum Crush

During the crush profile measurements, the point of max crush was located and recorded.

To obtain the height of max crush, a vertical measurement is taken from the max crush point to the ground (Figure 23). If the tires on the vehicle are flat, the height of the flattened side wall should be added to the measurement. However, if the vehicle is modified or damage prevents a reasonable estimate, do not use an exemplary or estimated measurement.

Door Sill Differential

FIGURE 22: DOOR

SILL DIFFERENTIAL

FIGURE 23:

HEIGHT OF

MAX CRUSH

6.0 Documentation of Vehicle Rollover OR Non-Horizontal Damage

Although Total Station measurements are not required for rollovers or non-horizontal damage, maximum lateral, maximum vertical, the max crush location is collected.

Rollover documentation measures the maximum crush at the greatest lateral and vertical locations to the greenhouse area of the vehicle. The max crush laterally and the max crush vertically may or may not occur to the same component. Documentation begins by identifying the points of max crush and establishing zones along the greenhouse of the damaged vehicle to best describe where the max crush occurred. Side plane zones are used to locate lateral crush, while top plane zones are used to locate vertical crush. See Figures 24 and 26.

In assigning the appropriate CDC in rollover configurations the following is used: 1) principal emphasis is given to the projected area of primary contact (that is, are of greatest crush) rather than initial contact and 2) damage to the greenhouse area (“P” in Column 4) is given priority over other vehicle areas such as “F” and “B”.

Contact damage in rollover configurations is classified in accordance with the following:

(this is listed in order of descending priority)

If the projected area of primary contact can be determined, use the appropriate character.

If the projected area of primary contact cannot be determined, use the angle of force in the vertical plane (above or below the horizontal clock face) to determine the appropriate character. If the direction of force is less than 45 degrees from the vertical axis, use “T”. If the direction of force is greater than 45 degrees from the vertical axis, use “L” or “R”.

If the direction of force cannot be determined with sufficient accuracy, use the projected area of the greatest contact to determine the appropriate character. If the deformation area of the left or rights side exceeds the deformation of the top, use “L” or “R”, respectively.

Use “T” if the deformation area is greater on the top.

6.1 Rollover Side Plane

6.1.1 Side Plane Zones

A-pillar Zone - Locate the top of the windshield frame and the center of the top of the B-pillar. Measure the distance and find the mid-point. From the foremost base of the A-pillar to the mid-point is the A-pillar Zone.

B-pillar Zone – Locate the center of the top of the B-pillar and the center of the top of the C-pillar. Measure the distance and find the mid-point. From the mid-point of the A and B pillars to the mid-point of the B and C pillars is the B-pillar Zone.

C-pillar Zone – Locate the center of the top of the C-pillar and the center of the top of the D-pillar. Measure the distance and find the mid-point. From the mid-point of the B and C pillars to the mid-point of the C and D pillars is the C-pillar area. If the C-pillar is the last of the pillars, the C-pillar Zone would end at the rearmost base of the C-pillar.

This same process is continued for each pillar present on the vehicle until the zones containing the max vertical and max lateral crush are identified.

Mid-point Mid-point Mid-point FIGURE 24:

ROLLOVER SIDE

PLANE ZONES

Top of windshield frame

Foremost base A-pillar

Top of B-pillar

Top of C-pillar

Top of D-pillar

A-pillar Zone

D-pillar Zone

C-pillar Zone

B-pillar Zone

6.1.2 Side Plane Rollover Measurements

Using tape measures or pocket rods, measure the maximum lateral crush from a fixed location on the vehicle such as the base of the side window to the most displaced component (i.e., roof side rail, A-pillar, etc.). To obtain a comparison (exemplar) value, measure the undamaged side of the vehicle or an exemplar from the same location See Figure 25. The difference of the two values is the resultant maximum lateral crush.

FIGURE 25: ROLLOVER

LATERAL MEASUREMENTS

6.2 Rollover Top Plane

6.2.1 Top Plane Zones

Top plane zones are established by extending the side plane zones across the roof as illustrated in Figure 26. Only three zones are established for the top plane: the Windshield Header Zone, the Roof Zone, and the Back Light Header Zone. In this example with an SUV, the B-pillar and C-pillar zones used for the side plane have been combined for the top plane to form the Roof Zone.

Right Windshield Header Zone

Right Back Light Header Zone

Right Roof Zone

Left Roof Zone

Left Windshield Header Zone

Left Back Light Header Zone

FIGURE 26: ROLLOVER TOP PLANE ZONES

6.2.2 Top Plane Measurement

Using tape measures or pocket rods, measure the maximum vertical crush from a fixed location on the vehicle such as the base of the side window, base of the windshield, or base of the backlight. To obtain a comparison (exemplar) value, measure the undamaged side of the vehicle or an exemplar from the same location See Figure 27. The difference of the two values is the resultant maximum vertical crush.

FIGURE 27: ROLLOVER TOP PLANE MEASUREMENTS

APPENDIX A

SEVERE UNDERRIDE DAMAGE

Not Applicable to Computer Reconstruction Program

Example A: Frontal impact - Damage is above the bumper/frame level. There is minimal engagement to the radiator and/or support components. Damage is generally restricted to the grille area, hood, and the top of the fenders.

Example B: An extension of Example A, damage continues into the greenhouse resulting in severe displacement of the hood, A pillars, windshield, and header.

Example C: Frontal impact: Damage is restricted to the greenhouse area. There is no contact below the beltline.

Note: Similar damage profiles to those represented in Examples A, B, and C which occur to the rear plane are also severe underrides.

Example D: Due to the lack of mechanical parts, the area between the beltline and frame is significantly less rigid in rear impacts than in frontal impacts. Consequently, impacts which are above the bumper/frame area and which result in crush that extends beyond the rearmost pillar area are generally considered severe underrides and are excluded from the computer reconstruction program.

Example E: Side impacts, which are restricted to the area above the beltline, specifically the greenhouse, are considered severe underrides and are excluded from most reconstruction programs.

Example F: Side impact - While door guard beams provide structural rigidity, impacts which are restricted to the area above the sill/frame require caution with respect to the use of a reconstruction program. In Example F substantial greenhouse damage involves nearly one half of the passenger compartment. In most cases, this constitutes severe underride; however, some reconstruction programs may apply to less severe impacts above the sill/frame. Also, this would probably result in a latch, hinge, or pillar failure, which would require using the averaging technique stated in section

5.3.1. to obtain a crush profile for use in the reconstruction program.

APPENDIX B

DOCUMENTING SHIFT/BOWING FOR CDC

LATERAL (HORIZONTAL) END SHIFT

For CDC incrementation purposes only, determine if the vehicle end structure (both frame rails or unibody) has shifted 10cm or more in the same direction. A technique for determining lateral (horizontal) end shift is to determine the undamaged centerline of the vehicle (best estimate usually made by aligning the inside rearview mirror with the center of the back light) and projecting the centerline to the end(s) of the vehicle. Refer to Figure 1b.

Measure the distance from the projected undamaged centerline to each frame rail end and compare this value to half the distance between the undamaged frame rails. A similar vehicle may have to be located to obtain this value. If an exemplar vehicle is not likely to be located, estimate the position of the undamaged frame end by projecting forward from the undamaged areas of the frame. Measure the half distance between the projected centerline and the projected undamaged frame end. If the measured value from the projected undamaged centerline differs from the half distance by 10cm or more for each frame rail end, check the appropriate box in the CISSWEB application to indicate shift.