Driver‐ and Passenger‐Side IIHS Small Overlap Frontal ... · PDF fileStructural intrusion targets were measured pre‐and post‐crash to evaluate structural deformation on the

Abstract Front crashworthiness evaluations by the Insurance Institute for Highway Safety include driver (left)

side small overlap (25%) frontal crash tests at 64 km/h with a rigid, radius‐edged flat barrier. Ratings are based

on occupant compartment structural integrity, driver dummy injury measures, and analysis of restraints and

dummy kinematics. Additional tests offset to the passenger (right) side were conducted with seven small SUVs

rated Good in left‐side tests to compare small overlap crash protection for drivers and front passengers. Provi‐

sional ratings based on right‐side tests ranged from Good to Poor. Higher right‐side occupant compartment

structural intrusion was the main reason for different assessments of driver and front passenger protection. Ad‐

ditionally, some near‐side front passenger dummies recorded higher forces on their outboard legs than their

near‐side driver counterparts. While injury measures from far‐side driver dummies suggest lower risk compared

with near‐side counterparts, observations of inadequate restraint system performance reveal a need to further

investigate their relevance with real‐world far‐side driver injuries. These results indicate a need for auto manu‐

facturers to consider both sides of the vehicle when developing front small overlap crash protection strategies

and may also indicate a need to include the driver dummy in right‐side evaluations of frontal small overlap

crashworthiness.

Keywords Far‐side, Front passengers, Near‐side, Small overlap tests, Structural symmetry

I. INTRODUCTION

The Insurance Institute for Highway Safety (IIHS) has conducted driver‐side (left) small overlap frontal crash

tests (64 km/h and 25% overlap) against a rigid, radius‐edged flat barrier as part of its consumer information

test program since 2012. Crashworthiness ratings are based on the structural integrity of the occupant com‐

partment, injury measures from a driver Hybrid III midsize male dummy, and analysis of restraints and dummy

kinematics. Many vehicles initially rated Poor, mainly because of collapse of the occupant compartment in the

area of the driver. The small overlap crash configuration is challenging because the frame rails and other struc‐

tures typically designed to manage crash energy are bypassed. Manufacturers have responded quickly to the

need for structural improvements for driver‐side small overlap protection. Since 2012, 97 models have been

structurally redesigned for small overlap crashes, and most designs were successful, with 72% receiving Good

ratings after the changes.

Three manufacturers — Honda, Volvo, and Subaru — have identified and documented their structural design

strategies to improve performance in the small overlap test [1‐6]. These strategies are typically achieved by

modifications to the vehicle structures, as shown in Fig. 1.

Fig. 1. Main vehicle structures identified for improvement in small overlap performance.

B.C. Mueller is Senior Research Engineer (email: [email protected]; tel: +1 434‐985‐4600) and J.M. Nolan is Chief Administrative Officer and Senior Vice President at the Insurance Institute for Highway Safety in Ruckersville, VA, USA.

Comparison of Vehicle Structure and Occupant Responses in

Driver‐ and Passenger‐Side IIHS Small Overlap Frontal Crash Tests

Becky C. Mueller and Joseph M. Nolan

IRC-16-83 IRCOBI Conference 2016

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Modifications include: visible rigid structures attached to the bumper beam, side frame, or engine cradle

forward of the wheel well; stronger upper inner‐fender (shotgun) structures tied into the main frame rail or

other energy‐absorbing structures; stronger occupant compartment firewall and doorframe structures such as

the A‐pillar, hinge pillar, rocker panel, and floorpan; and wheel and suspension modifications to promote energy

absorption and prevent the wheel from intruding into the occupant compartment.

A 2014 study by Mueller et al. [7] found that other automakers are employing similar strategies with changes

to at least some of these structural elements. All vehicles studied included reinforced occupant compartment

structure, but the most effective designs also included use of energy‐absorbing inner‐fender structures and the

addition of early engagement structures to induce vehicle lateral translation. This study also revealed that in

some of these vehicles, the countermeasures appeared to be applied only to the left side.

The IIHS small overlap front test currently only includes a driver dummy and is conducted with the barrier

overlapping the left side. Thus, as an initial attempt to improve front small overlap crashworthiness, left‐side

improvements are a reasonable strategy for automakers, especially as the driver seat is always (or nearly al‐

ways) occupied in real crashes. However, consumers likely reasonably expect that crashworthiness ratings are

meaningful for all seating positions. Moreover, analysis of real‐world injury data shows that right front passen‐

gers, when present, are at risk for injuries. In 2014, 1,673 right front passengers were killed in frontal crashes in

the United States [8]. A 2009 study of injured occupants in frontal crashes in vehicles with Good IIHS moderate

overlap ratings found 17% of case occupants were right front passengers [9]. Additionally, 24% of injured drivers

in small overlap configurations were located on the non‐struck side, and the majority of injuries were attributed

to inadequate restraint system performance. Ultimately, one would expect similar levels of protection for both

drivers and right front passengers in near‐side small overlap crashes.

The objective of this study was to examine the level of protection afforded to right front passengers in right‐

side small overlap crashes compared with drivers in left‐side crashes with the same small overlap configuration.

Additionally, the protection for drivers in left‐side and right‐side small overlap frontal crashes is also compared.

II. METHODS

Seven small SUV models that received Good IIHS overall ratings in small overlap left‐side tests following the

implementation of structural countermeasures were chosen for this study: 2015 Honda CR‐V, 2015 Toyota

RAV4, 2016 Hyundai Tucson, 2015 Subaru Forester, 2015 Buick Encore, 2014 Nissan Rogue, and 2015 Mazda CX‐

5 were subjected to right‐side small overlap tests. Right‐side small overlap tests were also performed on the

previous generation CR‐V and RAV4 prior to the implementation of any small overlap countermeasures in order

to compare the degrees of improvement on the driver and passenger sides.

Left‐Side Test Setup

All left‐side small overlap tests were conducted at a nominal speed of 64.4 km/h (40 mi/h) and a nominal 25% overlap with the IIHS small overlap barrier. All test setup and measurements followed the IIHS small over‐lap test protocol [10]. An instrumented Hybrid III midsize male dummy was installed in the driver seat for all tests. The dummy was seated according to the University of Michigan Transportation Research Institute (UMTRI) ATD positioning procedure [11], and grease paint was applied to the dummy’s head to document head contact locations, according to the IIHS small overlap frontal crash test protocol [10]. Dummy instrumentation included sensors in the head, neck, chest, and lower extremities. Comparison data include measures of structural defor‐mation, dummy injury metrics, and restraint system and dummy kinematics assessments.

Right‐Side Test Setup

All right‐side small overlap tests were prepared and conducted to match the paired left‐side tests, following the protocols in terms of test speed, configuration, overlap, and data, but offset to the right side [10]. Vehicles with the same trim levels and wheel types as the driver‐side tests were chosen to reduce variation.

The following test setup modifications were made: In addition to the instrumented Hybrid III midsize male driver dummy seated according to the UMTRI ATD positioning procedure [11], an additional Hybrid III midsize male dummy was installed in the right front passenger seat according to the Federal Motor Vehicle Safety Standard No. 208 procedure. Four onboard high‐speed cameras were installed focusing on the driver and right front passenger dummies to capture dummy kinematics and interaction with the restraint system. The overall vehicle test mass allowance was increased by 85 kg for the mass of the extra dummy and equipment.


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Structural intrusion targets were measured pre‐and post‐crash to evaluate structural deformation on the right‐side occupant compartment. The locations of these targets were chosen to compare with the standard left‐side intrusion targets [10], but also modified when necessary to capture structural intrusion relevant to the right front passenger seating position. For example, the steering wheel target is not relevant to a right front pas‐senger. Instead, a target on the dash in front the dummy, called center dash, provides a measure of the upper dash intrusion toward the dummy’s head and chest. A comparison of all intrusion target locations is shown in Fig. 2. Targets that can be compared directly are shown in Table I.

In the right‐side tests of the Honda CR‐V and Toyota RAV4, the standard driver‐side intrusion targets were recorded as well. This was discontinued in later testing because intrusion on the non‐struck side was found to be very low, on average 1 cm, even in vehicles with significant intrusion on the struck side.

Fig. 2. Locations of driver (left) and passenger (right) side intrusion targets.

TABLE I COMPARATIVE DRIVER AND PASSENGER – SIDE INTRUSION TARGETS

Driver‐side target Passenger‐side target

Upper hinge pillar Upper hinge pillar

Left instrument panel Right instrument panel

Steering wheel Center dash

Left toepan Right toepan

Brake pedal Center toepan

Upper dash Upper dash

Footrest Footrest

Lower hinge pillar Lower hinge pillar

Rocker panel (lateral) Rocker panel (lateral)

Comparing Left‐ and Right‐Side Tests

Three aspects of left‐side and right‐side tests were compared: dummy sensor measures, restraint system performance, and vehicle structure. Dummy sensor measures were compared for all instrumented body regions of the Hybrid III midsize male dummies: head, neck, chest, and lower extremities. Dummy kinematics were de‐termined using high‐speed video footage, excursion measurements, and contact evidence from paint transfer. Vehicle structural comparison was based on the pre‐ and post‐crash measurements between the standard driv‐er‐side intrusion targets [10] and the passenger‐side targets described previously in Table I.

Vehicle Ratings

Dummy sensor measures, restraint system performance, and vehicle structure are combined into an overall

rating for comparing vehicle performance. The ratings criteria for driver‐side small overlap impacts are in the

IIHS ratings protocols [12]. The left‐side criteria were modified to create comparable provisional ratings for the

right‐side impacts.

The right‐side structural rating was based on the same ratings logic as described in the IIHS ratings protocol


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[12], but for each of the driver‐side targets, the comparable passenger target is substituted (Table I). The driver

parking brake pedal target had no passenger side comparison and was excluded from the rating.

Rating of dummy injury measures follows the driver side protocol [12], but both the far‐side driver and near‐

side passenger dummy are included in the overall evaluation and carry equal weight.

The driver restraints and kinematics downgrades as stated in the official protocol [12] were applied directly

to the far‐side driver dummy, with the following modification for the near‐side passenger dummy: The demerit

count for head‐to‐airbag interaction for the passenger dummy was changed from one to two points for partial

and three points for minimal head‐to‐airbag interaction, accounting for the protection needed for a wide range

of possible occupant kinematics without the presence of a steering‐wheel‐mounted airbag.

The overall rating is based on the same number of overall points as the driver‐side rating protocol.

III. RESULTS

Vehicle Structural Performance Structural intrusion measures for the seven vehicles are shown in Fig. 3‐9. The seven vehicles tested on the

right side produced a wider range of performance than their comparative left‐side tests. The right side meas‐

ured greater intrusion than the left side for all vehicles except the Encore. For the Encore, the highest intrusion

was 14 cm on the left side and 12 cm for the right side; both values were from the lower hinge pillar target. For

the other vehicles, the right‐side maximum intrusion value ranged from 10 to 31 cm greater than the left‐side

maximum, and these values were not always at corresponding targets on the left and right sides of the same

vehicle.

Another indicator of structural similarity is the structural rating, which accounts for every intrusion target

value. Only the Encore would receive the same structural rating of Acceptable for both left and right sides, sug‐

gesting high levels of structural symmetry. Two vehicles, the CR‐V and Tucson, would receive a right‐side struc‐

tural rating one level below their left‐side rating (Acceptable instead of Good), still suggesting a reasonable level

of structural symmetry. These differences in structural performance fall within the expected level of left‐side

test‐to‐test repeatability documented for the IIHS small overlap crash configuration by Mueller et al. [13]. The

remaining three vehicles would receive two or three rating levels below, Marginal and Poor, on the right side,

suggesting largely different performance between left and right sides. These variations in intrusion are well out‐

side of the levels expected for test‐to‐test repeatability [13].

0

5

10

15

20

25

30

35

40

45

LowerHingePillar

Footrest LeftToepan

BrakePedal/CenterToepan

RockerPanel(lat)

SW/Centerof Dash

UpperHingePillar

UpperDash

LeftInstrument

Panel

Structural Intrusion (cm

)

Left

Right

Structural RatingsGood

Acceptable

0

5

10

15

20

25

30

35

40

45

LowerHingePillar

Footrest LeftToepan


RockerPanel(lat)

SW/Centerof Dash

UpperHingePillar

UpperDash

LeftInstrument

Panel


)

Left

Right


Poor

Fig. 3. CR‐V structural intrusion Fig. 4. RAV4 structural intrusion

0

5

10

15

20

25

30

35

40

45

LowerHingePillar

Footrest LeftToepan


RockerPanel(lat)

SW/Centerof Dash

UpperHingePillar

UpperDash

LeftInstrument

Panel


)

Left

Right


Acceptable

0

5

10

15

20

25

30

35

40

45

LowerHingePillar

Footrest LeftToepan


RockerPanel(lat)

SW/Centerof Dash

UpperHingePillar

UpperDash

LeftInstrument

Panel


)

Left

Right


Poor

Fig. 5. Tucson structural intrusion Fig. 6. Forester structural intrusion


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0

5

10

15

20

25

30

35

40

45

LowerHingePillar

Footrest LeftToepan


RockerPanel(lat)

SW/Centerof Dash

UpperHingePillar

UpperDash

LeftInstrument

Panel


)Left

Right

Structural RatingsAcceptable

Acceptable

0

5

10

15

20

25

30

35

40

45

LowerHingePillar

Footrest LeftToepan


RockerPanel(lat)

SW/Centerof Dash

UpperHingePillar

UpperDash

LeftInstrument

Panel


)

Left

Right


Poor

Fig. 7. Encore structural intrusion Fig. 8. Rogue structural intrusion

0

5

10

15

20

25

30

35

40

45

LowerHingePillar

Footrest LeftToepan


RockerPanel(lat)

SW/Centerof Dash

UpperHingePillar

UpperDash

LeftInstrument

Panel


)

Left

Right


Marginal

Fig. 9. CX‐5 structural intrusion

Comparing the current RAV4 and CR‐V to their previous versions before small overlap countermeasures (Ta‐

ble II), both the CR‐V and RAV4 left sides indicated large reductions in structural intrusion of 21 and 22 cm, re‐

spectively. Those large reductions were not observed on the right side after design changes. The CR‐V measured

the greatest reduction in intrusion of 5 cm, while the RAV4 did not indicate a reduction, measuring 1 cm more

intrusion after design changes.

TABLE IISTRUCTURAL COMPARISON OF VEHICLES BEFORE AND AFTER DESIGN CHANGES (CM)

CR‐V RAV4 Left Right Left Right Maximum intrusion Before After Before After Before After Before After

Lower occupant compartment

6 5 20 15 31 9 39 40

Upper occupant compartment

31 4 19 14 21 5 25 26

Reduction 21 5 22 ‐1 (increase) Injury Measures for Near‐side Driver and Passenger Dummies

Dummy sensor measures are listed in Appendix B. Maximum dummy sensor measures for a given body re‐

gion — head, neck, chest, thigh/hip, and leg/foot — relative to Injury Assessment Reference Values (IARVs) are

shown in Fig. 10‐15. None of the vehicles recorded dummy injury measures exceeding IARVs.

All passenger dummies in right‐side tests (referred to as near‐side passenger dummies) and driver dummies

in left‐side tests (near‐side driver dummies) registered head injury criteria (HIC) below 400 and neck injury crite‐

rion (Nij) below 0.38, mainly because the only head contacts were with the frontal airbag. The higher chest inju‐

ry risks for near‐side drivers and near‐side passengers were typically from chest accelerations and recorded

peak accelerations of 38% to 70% of the IARV. The two exceptions were the Tucson near‐side passenger and

Rogue near‐side passenger and near‐side driver, for which the highest chest injury risks of 34% and 54% of the

IARV, respectively, were associated with chest deflection measurements. For knee, thigh, or hip injuries, the

maximum risks came from a mix of knee displacements and femur force values. All near‐side passenger knee,


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thigh, or hip IARVs were below 46%, except for the CR‐V, in which the femur load cell recorded 6.1 kN from con‐

tact with the glove box handle, associated with 68% of the sensor’s IARV.

In three vehicles — the Tucson, Forester, and RAV4 — the near‐side passenger dummy had at least one low‐er extremity sensor measure exceeding 80% of the IARV, the cutoff for a Good rating, while the driver dummy in the paired left‐side test recorded measures below that cutoff. A high level of intrusion (21 cm) along the knee bolster was likely the main reason for higher injury measures for the RAV4 and Forester. Contact with the trim components of the glove box likely contributed to elevated measures in the Tucson. In the CR‐V, the near‐side driver recorded lower extremity measures exceeding 80% of the IARVs, whereas the paired near‐side passenger did not.

0% 20% 40% 60% 80% 100% 120%

CR‐V

RAV4

Tucson

Forester

Encore

Rogue

CX‐5

Percent of IARV

Nearside driver Nearside passenger Farside driver

0% 20% 40% 60% 80% 100% 120%

CR‐V

RAV4

Tucson

Forester

Encore

Rogue

CX‐5

Percent of IARV


Fig. 10. Peak head sensor measures Fig. 11. Peak neck sensor measures

0% 20% 40% 60% 80% 100% 120%

CR‐V

RAV4

Tucson

Forester

Encore

Rogue

CX‐5

Percent of IARV


0% 20% 40% 60% 80% 100% 120%

CR‐V

RAV4

Tucson

Forester

Encore

Rogue

CX‐5

Percent of IARV


Fig. 12. Peak chest acceleration measures Fig. 13 Peak chest deflection measures

0% 20% 40% 60% 80% 100% 120%

CR‐V

RAV4

Tucson

Forester

Encore

Rogue

CX‐5

Percent of IARV


0% 20% 40% 60% 80% 100% 120%

CR‐V

RAV4

Tucson

Forester

Encore

Rogue

CX‐5

Percent of IARV


Fig. 14. Peak thigh/hip sensor measures Fig. 15. Peak leg/foot sensor measures


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Injury Measures for Near‐side and Far‐side Driver Dummies

Far‐side driver sensor measures for all body regions except the chest were lower when compared with the near‐side drivers. All HIC measures were low, mainly because the only head contacts were with the frontal air‐bag. Tibia indices for all far‐side dummies were below 0.4. In three vehicles, the far‐side dummy’s legs did not contact the knee bolster during the test.

Far‐side driver chest measures indicated a mix of results when compared with near‐side drivers. While chest

accelerations typically indicated the higher injury risks for near‐side drivers compared to chest deflection, the

opposite was true for far‐side drivers where the range of 38% to 66% of IARV came from chest deflections. Far‐

side driver chest accelerations were lower than near‐side drivers for all vehicles. Chest deflection measures

were slightly higher compared with near‐side drivers, by 2‐10 mm in all vehicles except the Encore (Table III).

Higher belt loading for far‐side occupants, supported only by the frontal airbag and seat belt, translates into the

higher observed chest deflections compared with near‐side occupants, typically receiving additional support

from the curtain airbag. In the Encore, however, the shoulder belt slid off the dummy’s shoulder and crossed

the chest below the sternum where the chest deflection sensor is located.

TABLE III DRIVER CHEST COMPRESSION (MM)

Vehicle model Near‐side Far‐side Vehicle model Near‐side Far‐side

2015 Honda CR‐V 22 26 2015 Subaru Forester 26 28

2015 Toyota RAV4 22 24 2015 Buick Encore 25 22

2013 Toyota RAV4 18 22 2014 Nissan Rogue 27 33

2014 Honda CR‐V 13 19 2015 Mazda CX‐5 24 27

2016 Hyundai Tucson 23 33

Dummy Kinematics

All vehicles had timely frontal airbag deployments in both left‐ and right‐side small overlap configurations. In

most of the tests, the near‐side dummy had stable head interaction with the airbag, and no head contact was

observed with any vehicle interior components. Typical airbag interaction is shown in Fig. 15. The exceptions are

the near‐side dummy in the Nissan Rogue passenger‐side test, the near‐side driver dummy in the older‐

generation RAV4 before design changes, and both the near‐side driver and passenger in the older generation

CR‐V before design changes (Fig. 16).

A lack of steering column stability and high intrusion contributed significantly to the deficiency in airbag pro‐

tection for near‐side drivers in the older‐generation vehicles. Although the right side in the Rogue and previous‐

generation CR‐V had large intrusion, the narrow shape of the frontal passenger airbag also contributed to the

unstable frontal airbag interaction. Despite similarly high levels of intrusion, this lack of airbag protection did

not occur for the Forester, CX‐5 or RAV4. Far‐side driver dummies moved significantly inboard but remained

fully engaged with the frontal airbag in tests of all vehicles except the Encore, in which the dummy’s head par‐

tially slid off the right edge of the frontal airbag (Fig. 17).

Fig. 15. Stable airbag interaction for near‐side driver (left) and far‐side driver and near‐side

passenger (right) in the Mazda CX‐5.


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Fig. 16. Movement of near‐side passengers in the Nissan Rogue (left) and previous‐generation

CR‐V (right) indicated a gap in frontal airbag protection due to the airbag’s narrow shape.

Fig. 17. The far‐side driver dummy had typical stable interaction with the frontal airbag in the Hyundai

Tucson (left). The Buick Encore was the only vehicle in which the far‐side driver dummy’s head slid into

a gap in forward protection (right).

One additional restraint system observation was made for the current Toyota RAV4 in the right‐side test but

not in the left‐side test. The door latch cable activated, opening the door. An open door presents a risk for ejec‐

tion and results in an automatic Poor rating for restraints and kinematics.

Vehicle Ratings

Provisional ratings were calculated for all right‐side small overlap tests (Table IV). The seven study vehicles

with Good left‐side ratings received a wide range of right‐side ratings. Only the Hyundai Tucson receives the

same overall Good rating for the left and right sides. For all other vehicles, the right‐side rating was at least one

rating category worse, with two vehicles, the Forester and Rogue, reduced two levels to Marginal and the RAV4

reduced three levels to Poor. The main contributors to these lower ratings were the Poor structural ratings of

the Forester, Rogue, and RAV4, plus, in the case of the RAV4, a Poor kinematic rating due to the opening of the

door during the crash. Only the Encore had the same structural rating for the left and right sides, but Acceptable

restraints and kinematics for the far‐side driver resulted in an overall downgrade to Acceptable on the passen‐

ger side.

Table IV. Vehicle small overlap ratings comparison

Driver Passenger (provisional)

2016 Hyundai Tucson Good Good

2015 Honda CR‐V Good Acceptable

2015 Buick Encore Good Acceptable

2015 Mazda CX‐5 Good Acceptable

2015 Subaru Forester Good Marginal

2014 Nissan Rogue Good Marginal

2015 Toyota RAV4 Good Poor


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IV. DISCUSSION

Structural Performance

The biggest differences between left‐ and right‐side results were observed for the Forester, RAV4, and

Rogue. Two of these models, the RAV4 and Rogue, incorporated engagement and energy‐absorbing structures

on the left side that were not present on the right side, shown in Fig. 18. The left‐ and right‐side differences in

the Forester were due to different materials (likely steel type or material thickness) used in components around

the occupant compartment doorframe. The other models had similar intrusion measurements in both left‐ and

right‐side tests, even if right‐side intrusion was generally somewhat greater than on the left side. Though limited

to two vehicles, results for both the visibly asymmetric RAV4 and Rogue suggest that the lack of visible small

overlap structures on the right side is an indicator of reduced structural performance on that side compared

with the left side. These differences cannot simply be explained as test variation. These vehicles experienced 26

to 34 cm differences in intrusion from the left to right side, much greater than the 8 cm level of repeatability

established by Mueller et al. [13].

Fig. 18. Visual differences between driver‐ and passenger‐side structures for Toyota RAV4 (left) and Nissan

Rogue (right).

At the same time, results from visually symmetric vehicles show that such assessments do not guarantee

comparable performance in left‐ and right‐side impacts. The Encore performed well in the right‐side test, with

the greatest structural variation of only 8 cm between the left and right sides. In contrast, the greatest structural

variation between the two sides on the CX‐5 and Forester was 18 and 21 cm, respectively. It should be noted

that beyond specific small overlap countermeasures, structural asymmetry exists in many vehicles with trans‐

verse engine and transmission configurations. In addition, steering assemblies, braking components, etc. all are

typically placed on the driver side, while the right front passenger is not exposed to them.

Dummy Injury Measures and Kinematics

In both vehicles with and without symmetric structural countermeasures, there were some indications of the

need for improvements to restraint systems. Compared with driver occupants, there are fewer challenges asso‐

ciated with airbag protection for passengers because the passenger frontal airbag is typically larger than the

driver airbag and located in the dash instead of the steering wheel, which often moves out of position when the

instrument panel intrudes. High levels of instrument panel intrusion on the passenger side were typically associ‐

ated with leg injury measures exceeding a Good boundary of 80% of the IARV, while the comparable driver‐side

results with low structural intrusions indicated low risk of leg injury, within the Good boundary. All other aspects

of the passenger injury measures and kinematics were similar to those of the near‐side driver dummies.

In all right‐side tests regardless of symmetry, the far‐side driver injury measures indicated a low risk of injury,

due to the lack of structural intrusion into the far‐side occupant compartment space. Most far‐side driver dum‐

mies had stable interaction with the frontal airbag, and there were no hard head contacts. The exception was

the Encore test, in which the driver dummy shoulder belt partially slipped off and allowed the head to partially

slide off the airbag toward the center stack. In all other vehicle pairs, the chest compressions for the far‐side

driver were greater than for the near‐side driver, though none indicated values greater than 70% of the IARV.


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For the far‐side driver, the seat belt likely plays a larger role in restraining the dummy and, therefore, there is

greater chest loading compared with the near‐side driver. Observations from left‐side tests indicate the driver

dummy’s lateral motion is partially controlled by the curtain airbag, requiring less loading by the belt. While the

far‐side driver faces lower injury risks compared with the near‐side passenger, observations about restraint sys‐

tem performance hint that there are still potential risks that cannot be ignored. These observations also align

with the real‐world far‐side driver injury mechanisms identified by Brumbelow and Zuby [9]. Additionally, the

driver seat is always occupied in real‐world crashes, and this new evaluation provides an opportunity to monitor

and improve performance of the driver‐side restraint system in these types of crashes. No conclusions about

observed injury risks for right front passenger dummies in driver‐side small overlap crashes can be made, as no

tests have been conducted in that configuration. Further research is needed to fully evaluate the real‐world rel‐

evance of far‐side occupant injuries for both drivers and right front passengers in small overlap crashes.

V. CONCLUSIONS

IIHS has been rating vehicles for small overlap protection on the basis of left‐side tests since 2012. These rat‐

ings have encouraged manufacturers to make structural changes to vehicles in order to earn higher ratings. No

such incentive exists to make improvements to the right side. Early on, IIHS encouraged implementing left‐side‐

only countermeasures in the short‐term if it meant more models would be outfitted with countermeasures, but

it was always assumed that future designs would provide comparable levels of protection on both sides of the

vehicle. Consumers are unlikely to accept that vehicles provide different levels of protection on the left and right

sides of vehicles.

The range of performance in right‐side small overlap tests among vehicles with Good left‐side small overlap

ratings suggest automakers have not yet consistently applied design changes to both sides of the vehicle. These

tests also highlight the need to evaluate vehicle protection for far‐side drivers. While far‐side driver dummies

indicate reduced risks compared with their near‐side counterparts that experienced higher structural intrusions,

observations of inadequate restraint system performance suggest a potential need to evaluate risks for far‐side

drivers in this crash mode.

IIHS will continue to monitor differences in small overlap driver‐ and passenger‐side performance and may

begin issuing passenger‐side small overlap ratings as early as 2018.

VI. REFERENCES

[1] Thomas C. The role of the vehicle structure in reducing injuries in small overlap crashes. Proceedings of International Automotive Body Congress, Troy, Michigan, 2011.

[2] Fuju Heavy Industries Ltd. Subaru 14MY Forester: concept of small overlap collision. May 2014.

[3] Jakobsson L, McInally G, Axelson A, Lindman M, Kling A, Broberg T, Fermér M, Wågström L. Severe frontal collisions with partial overlap: two decades of car safety development. SAE Technical Paper 2013‐01‐0759. Warrendale, PA: SAE International, 2013.

[4] Ohnaka, R. 2013 Honda Accord: NVH collision safety. Proceedings International Automotive Body Con‐gress 2012. Red Hood, NY: Curran Associates Inc., 2013, 136‐151.

[5] Planath I. Norin H, Nilsson S. Severe frontal collisions with partial overlap: significance, test methods and car design. SAE Technical Paper 930636. Warrendale, PA: SAE International, 1993.

[6] Weissler P. 2014 MDX re‐engineered to pass IIHS test, reduce NVH. Automotive Articles, June 7. Warren‐dale, PA: SAE International, 2014.

[7] Mueller BC, Brethwaite AS, Zuby DS, Nolan JM. Structural design strategies for improved small overlap crashworthiness performance. Stapp Car Crash Journal, 2014, 58:145‐174.

[8] Insurance Institute for Highway Safety. [Unpublished analysis of data from the Fatality Analysis Report System]. Arlington, VA, 2016.

[9] Brumbelow ML, Zuby DS. Impact and injury patterns in frontal crashes of vehicles with good ratings for frontal crash protection. Proceedings of ESV Conference, 2009, Stuttgart, Germany.


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[10] Insurance Institute for Highway Safety. Small overlap frontal crashworthiness evaluation crash test proto‐col (version III). Ruckersville, VA, 2014.

[11] Insurance Institute for Highway Safety. Guidelines for using the UMTRI ATD positioning procedure for ATD and seat positioning (version V). Ruckersville, VA, 2004.

[12] Insurance Institute for Highway Safety. Small overlap frontal crashworthiness evaluation rating protocol (version III); rating guidelines for restraints and dummy kinematics, injury measures, and vehicle structur‐al performance; weighting principles for overall rating. Ruckersville, VA, 2014.

[13] Mueller BC, Sherwood CP, Nolan JM, Zuby DS. Repeatability of IIHS small overlap frontal crash tests. Pro‐ceedings of ESV Conference, 2013, Seoul, Republic of Korea.

VII. APPENDICES

Appendix A

TABLE A‐1

FAR‐SIDE INTRUSION

2015 Honda

CR‐V

2014 Honda

CR‐V

2015 Toyota

RAV4

2013 Toyota

RAV4

Lower hinge pillar (cm) 1 1 0 1

Footrest (cm) 2 1 0 1

Left toepan (cm) 2 1 1 1

Brake pedal (cm) 2 1 0 0

Rocker panel (lateral) (cm) 0 0 0 0

Steering column (longitudinal) (cm) 0 0 0 0

Upper hinge pillar (cm) 1 1 0 0

Upper dash (cm) 1 1 0 1

Left instrument panel (cm) 1 1 0 0


- 630 -

TABLE

A‐2

A

NEA

R‐SIDE INTR

USION

2015 Honda CR‐V

2015 Toyo

ta RAV4

2016 Hyu

ndai Tucson

2015 Subaru Forester

2015 Buick En

core

Driver

Passenger

Driver

Passenger

Driver

Passenger

Driver

Passenger

Driver

Passenger

Lower hinge pillar (cm

) 3

15

9

40

5

19

9

29

14

11

Footrest (cm

) 5

13

640

715

10

24

911

Left toep

an (cm

) 3

8

2

23

6

11

6

17

8

7

Brake ped

al/cen

ter toep

an (cm

) 4

3

3

22

6

9

6

11

9

1

Rocker pan

el (lateral) (cm

) 2

4

2

17

2

12

0

4

2

4

Stee

ring whee

l/center of dash (cm

) 2

61

82

6

010

46

Upper hinge pillar (cm

) 4

14

4

26

4

11

5

26

14

12

Upper dash (cm

) 4

10

5

23

5

3

4

13

12

6

Left in

strument pan

el (cm

) 4

8

5

21

4

8

2

21

12

10

TA

BLE

A‐2

B

NEA

R‐SIDE INTR

USION

2014 Nissan Rogu

e

2015 M

azda CX‐5

2014 Honda CR‐V

2014 Toyo

ta RAV4

Driver

Passenger

Driver

Passenger

Driver

Passenger

Driver

Passenger

Lower hinge pillar (cm

) 10

36

725

26

20

31

39

Footrest (cm)

3

16

7

17

15

17

20

25

Left toep

an (cm

) 2

13

5

6

13

5

4

13

Brake ped

al/cen

ter toep

an (cm

) 3

7

8

3

10

3

7

9

Rocker pan

el (lateral) (cm

) 2

21

414

9

12

16

Stee

ring whee

l/center of dash (cm

) 3

12

0

8

11

5

4

9

Upper hinge pillar

9

20

8

20

31

19

21

25

Upper dash

8

9

7

9

26

12

17

25

Left in

strumen

t pan

el

9

24

813

26

10

17

19


- 631 -

Appen

dix B

TABLE

B‐1

A

INJURY MEA

SURES

2015 Honda CR‐V

2015 Toyo

ta RAV4

2013 Toyo

ta RAV4

Nea

r‐side

Driver

Passenger

Far‐side

Driver

Nea

r‐side

Driver

Passenger

Far‐side

Driver

Nea

r‐side

Driver

Passenger

Far‐side

Driver

Measure (units)

IARV

CEN

1444

CN15001

CN15001

CEN

1451

CN15002

CN15002

CEN

1319

CN15003

CN15003

HIC

700

137

116

99

163

102

33

283

58

42

BrIC

1

1

1

0

1

1

0

1

0

0

Neck A‐P shea

r force (kN)

‐3

‐1

0

0

‐1

0

0

‐1

0

‐1

Nij

1

0.30

0.16

0.20

0.26

0.23

0.15

0.27

0.18

0.17

Neck axial compression (kN

) 4

0

0

0

0

0

0

0

0

0

Neck axial tension (kN

) 3

1

1

1

1

1

1

2

1

1

Chest acceleration (3 m

s clip) (g)

60

33

27

23

42

26

17

27

26

16

Chest compression (mm)

50

22

20

26

22

21

24

18

16

22

Sternum deflection rate (m

/s)

8

‐1

‐1

‐1

‐1

‐1

‐1

‐1

‐1

‐1

Viscous criteria (m/s)

1

0

0

0

0

0

0

0

0

0

Left KTH

injury

0

0

0

0

0

0

0

0

0

Left fem

ur force (kN)

9

01

02

1

23

11

Left knee displacemen

t (m

m)

15

0

2

1

0

2

2

5

1

1

Left upper tibia index

1

1

0

0

0

1

0

1

0

0

Left lo

wer tibia index

1

0

0

0

0

1

0

1

1

0

Left tibia axial force (kN)

8

21

04

1

15

11

Left foot acceleration (g)

150

56

49

23

62

71

32

67

96

41

Right KTH

injury

0

7

0

0

0

0

0

1

0

Right femur force (kN)

9

0‐6

0‐1

‐2

‐1‐1

‐3‐1

Right kn

ee displacemen

t (m

m)

15

03

01

4

31

41

Right upper tibia in

dex

1

1

1

0

0

0

0

0

0

0

Right lower tibia in

dex

1

1

0

0

0

1

0

0

1

0

Right tibia axial force (kN)

8

‐1‐1

‐1‐2

‐1

‐1‐2

‐1‐1

Right foot acceleration (g)

150

61

46

41

47

118

50

125

103

56


- 632 -

TA

BLE

B‐1

B

INJURY MEA

SURES

2014 Honda CR‐V

2016 Hyundai Tucson

2015 Subaru Forester

Nea

r‐side

Driver

Passenger

Far‐side

Driver

Nea

r‐side

Driver

Passenger

Far‐side

Driver

Nea

r‐side

Driver

Passenger

Far‐side

Driver

Measure (units)

IARV

CEN

1223

CN15004

CN15004

CEN

1522

CN15005

CN15005

CEN

1303

CN15006

CN15006

HIC

700

102

34

31

399

321

61

127

77

44

BrIC

1

1

0

0

1

1

1

1

0

0

Neck A‐P shea

r force (kN)

‐3

‐1‐1

01

0

00

‐1‐1

Nij

1

0.36

0.19

0.15

0.36

0.19

0.15

0.36

0.19

0.15


) 4

0

0

0

0

0

0

0

0

0


) 3

1

1

1

1

1

1

0

1

1


s clip) (g)

60

32

23

15

42

51

25

32

35

19


50

13

16

19

23

27

33

26

25

28


/s)

8

‐1

‐1

‐1

‐1

‐2

‐1

‐1

‐2

‐1


1

0

0

0

0

0

0

0

0

0

Left KTH

injury

4

00

00

00

00

Left fem

ur force (kN)

9

5

1

0

2

0

0

2

2

1


t (m

m)

15

8

1

0

9

2

0

4

2

3


1

1

0

0

1

0

0

0

1

0

Left lo

wer tibia index

1

10

00

0

00

00


8

6

2

1

2

1

0

2

2

1


150

79

28

24

55

69

47

50

129

55

Right KTH

injury

0

11

0

0

0

0

0

1

0


9

‐1‐7

00

‐1

0‐1

‐4‐1

Right kn

ee displacement (m

m)

15

3

4

0

0

3

1

1

10

2


dex

1

1

1

0

0

1

0

0

1

0


dex

1

0

1

0

1

1

0

0

1

0


8

‐2‐4

‐1‐1

‐2

‐1‐2

‐2‐1


150

66

108

32

83

52

38

47

73

35


- 633 -

TA

BLE

B‐1

C

INJURY MEA

SURES

2015 Buick En

core

2014 Nissan Rogu

e 2015 M

azda CX‐5

Nea

r‐side

Driver

Passenger

Far‐side

Driver

Nea

r‐side

Driver

Passenger

Far‐side

Driver

Nea

r‐side

Driver

Passenger

Far‐side

Driver

Measure (units)

IARV

CEN

1502

CN15007

CN15007

CEN

1407

CN15008

CN15008

CEN

1345

CN15009

CN15009

HIC

700

107

110

105

185

68

53

181

120

62

BrIC

1

1

1

1

1

1

0

1

0

1

Neck A‐P shea

r force (kN)

‐3

00

1‐1

‐1

‐10

00

Nij

1

0.23

0.17

0.26

0.29

0.24

0.19

0.26

0.25

0.18


) 4

0

0

0

0

0

0

0

0

0


) 3

1

1

1

1

1

1

1

1

1


s clip) (g)

60

34

25

19

30

20

18

36

38

22


50

25

25

22

27

17

33

24

19

27


/s)

8

‐1

‐1

‐1

‐1

‐2

‐2

‐1

‐1

‐1


1

0

0

0

0

0

0

0

0

0

Left KTH

injury

1

00

00

00

00

Left fem

ur force (kN)

9

4

1

0

2

3

0

1

2

0


t (m

m)

15

7

4

0

2

5

0

3

6

1


1

1

1

0

0

0

0

0

0

0

Left lo

wer tibia index

1

00

00

0

00

00


8

2

2

0

1

1

0

1

2

0


150

56

46

35

28

45

44

52

34

47

Right KTH

injury

0

1

0

0

2

0

0

1

0


9

0‐4

‐10

‐4

00

‐30

Right kn

ee displacement (m

m)

15

2

5

4

0

5

1

0

3

1


dex

1

0

1

0

0

1

0

0

0

0


dex

1

0

0

0

0

1

0

0

1

0


8

‐1‐2

0‐1

‐1

0‐2

‐2‐1


150

49

50

49

26

48

33

58

57

27


- 634 -

Documents

Driver‐ and Passenger‐Side IIHS Small Overlap Frontal ... · PDF fileStructural intrusion targets were measured pre‐and post‐crash to evaluate structural deformation on the