EUROPEAN NEW CAR ASSESSMENT PROGRAMME(Euro NCAP)ASSESSMENT PROTOCOL – OVERALL RATING
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EUROPEAN NEW CAR ASSESSMENT PROGRAMME (Euro NCAP)ASSESSMENT PROTOCOL – OVERALL RATING

Table of Contents
1INTRODUCTION................................................................................................................... 12

PRINCIPLES .......................................................................................................................... 13

OVERALL RATING CALCULATION ............................................................................... 33.1Method ..........................................................................................................................................3

3.2

Weight Factors and Limits .........................................................................................................3

3.3

Balance Criteria ...........................................................................................................................4

3.4

Rounding ......................................................................................................................................4

APPENDIX I ................................................................................................................................... 6

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EUROPEAN NEW CAR ASSESSMENT PROGRAMME (Euro NCAP)ASSESSMENT PROTOCOL – OVERALL RATING

1INTRODUCTION

Euro NCAP’s original assessment protocol was developed jointly by TRL and Vehicle Safety
Consultants Ltd., under contract to the UK Department of the Environment Transport and theRegions and International Testing, respectively. Subsequent versions of the protocol have beendeveloped and released by the Euro NCAP Secretariat. Beginning with Version 5, importantchanges have been included that have been brought about by the introduction of the overall rating
scheme. Individual documents are released for the four main areas of assessment:Assessment Protocol – Adult Occupant Protection;
Assessment Protocol – Child Occupant Protection;
Assessment Protocol – Pedestrian Occupant Protection;
Assessment Protocol – Safety Assist;

In addition to these four assessment protocols, the present document is provided describing themethod and criteria by which the overall safety rating is calculated on the basis of the car
performance in each of the above areas of assessment.

2PRINCIPLESThe Euro NCAP programme is designed to provide a fair, meaningful and objective assessment of
the safety performance of cars. It is intended to inform consumers, so providing an incentive tomanufacturers as well as giving credit to those who provide maximum protection. The impact
tests are based on those developed for legislation by the European Enhanced Vehicle safety
Committee (EEVC) for frontal and side impact protection of car occupants and for the protectionof pedestrians hit by the front of cars. Other tests are derived from existing legislative tests (suchas the assessment of speed limiters), based on existing consumer tests (like whiplash) orcompletely developed by Euro NCAP (for example seat belt reminders).
The overall safety rating covers the protection of adults and children in the event of a car crashand that of vulnerable road users who may be struck by the car. In addition, the rating addresses
the ability of the car to support safer driving. No stylised test procedure fully reflects the safety
provided by a car in the wide variety of accidents or near-accidents which may occur on the roads.
However, cars that perform well in these tests should be generally less exposed to and provide
better protection in accidents than cars which perform less well. The limitations of using
standardised crash test dummies in fixed seating positions in the crash tests is partly overcome bytaking into account other information related to occupant kinematics, interior contact points andvehicle structure, collected as part of post-crash vehicle inspections.
Version 5.1
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variations a number of actions have been taken:a)

Manufacturers have been asked to compare the results from these tests with those fromtests they may have conducted and to draw our attention to any anomalies they may find.
They have also been requested to supply data from their own tests to us for comparison.
Several manufacturers have supplied data for this purpose. Apart from considering theeffects of test variation and identifying anomalies, no account of such data is taken in
rating the cars and it is kept confidential.

b)

The overall assessments are based on the combination of multiple results. Variations in
any one of these will only have a limited effect on the overall rating.

The least demanding performance boundaries for the frontal and side impact parameters havebeen set to be equivalent to the limits proposed in the EEVC test procedures. The EEVC limits
were set to provide a basic minimum level of protection and to protect only in a moderateproportion of accidents. For car occupants, these limits are too lenient to adequately identify bestpractice in current production cars and to provide a goal for further improvement. Additional,
more demanding, protection boundaries have been set, to identify aspects of a car’s performance
which offer significantly greater protection. With the current level of pedestrian protection
provided by car fronts, it would be optimistic to adopt a similar approach for the bodyform tests.
In order to discriminate cars which just meet the EEVC requirements from those which greatly
exceed them, a lower limit has been set. Assessment of the safety assist functions is based both on
fitment requirement and performance requirements or fitment requirements alone. The intention isto promote standard fitment across the car volume sold in the European Community in
combination with good functionality for these systems.

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23

OVERALL RATING CALCULATION

3.1

MethodThe overall rating is composed of scores achieved in the four areas of assessment, also referred toas “boxes”: Adult Occupant, Child Occupant and Pedestrian Protection and Safety Assist. Thescore in each box is based on the car performance in different tests.
For each box, a total score is normalised with respect to the maximum achievable score availablefor the box. In this way, the maximum score for each box, and hence the total maximum score, isa constant. The weighted overall score is calculated from the individual assessment scores using
weight factors. These weight factors reflect the relative importance of the four boxes in the finalscore. Foremost, the selection of percentages is guided by real world priorities and societal
considerations. At the same time, the number and expected effectiveness (in terms of expected
accident and injury reduction) of the protocols in each box are considered.
The overall weighted score, determined by taking the weighted average of the scores in the fourboxes, is used to generate the overall star rating by applying the score against the percentage scorerequired for each star. Vehicles that show a poor performance in one of the boxes will have theirstar rating restricted to show that they do not provide good all-round protection. There will be aminimum score required in each box to validate a star rating. See Figure 3.1 (Appendix I) for aflow diagram of the method of calculation of the overall star rating.
3.2

Weight Factors and Limits

The weighted overall score is calculated from the individual scores in each box using weightfactors. These weight factors are fixed for a certain period but may be updated from time to time
as priorities or the contents of the boxes change. A change in weight factors will become effective
no sooner than at the start of the year following the year in which the decision was made. Table
3.1 summarises the weight factors applied in the upcoming period.
Table 3.1
Weight factors
Year2009

2010

2011

2012

Box 1: Adult Occupant Protection

50%

50%

50%

50%

Box 2: Child Occupant Protection

20%

20%

20%

20%

Box 3: Pedestrian Protection

20%

20%

20%

20%

Box 4: Safety Assist

10%

10%

10%

10%

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Provided there is sufficient balance between the four boxes, the weighted score, after rounding,applies to star values according to the following scheme:
Table 3.2
Total points applied to star values, based on weighting
Year3.3

20092010

2011

2012

For five stars, at least:

70%

75%

75%

80%

For four stars, at least:

55%

60%

60%

70%

For three stars, at least:

45%

50%

50%

60%

For two stars, at least:

35%

35%

35%

55%

For one star, at least:

20%

25%

25%

45%

Balance Criteria

Additional criteria are applied to the individual scores in order to assess all-round performance.
The limits given in Tables 3.3a, 3.3b and 3.3c are applied after the individual test scores havebeen rounded.
3.4

Rounding

The following rounding rules will be applied in the calculation of the overall rating.
The points score in each box is rounded to 3 decimal points. For instance, a total of added
points for front, side, pole and whiplash of 25.1238 would be rounded off to 25.124;
To calculate the score in each box, the 3 decimal result is then divided by the maximum
points available for that box and the resulting percentage is rounded to 0 decimal points
i.e. to an integer. In the example case: 25.124 / 36 * 100% = 69.789 is rounded to 70%;
That integer is then compared with the balance percentage thresholds for the box in Table
3.3. In the example case 70% qualifies for 5 stars in 2009;
The overall weighted score is calculated by multiplying the individual integers with theweight factors rounding the result to one decimal point. The contributions of the fourboxes are added and finally rounded-off to 0 decimal points. This number is compared to
the limits in Table 3.2.

Euro NCAP provides a Calculation Spreadsheet at request.

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Table 3.3aBalance limits for year 2009
2009

Box 1:
Adult OccupantBox 2:
Child OccupantBox 3:
PedestrianBox 4:
Safety Assist

5 stars75%70%

25%

60%

4 stars

60%

55%

15%

40%

3 stars

30%

30%

10%

25%

2 stars

25%

25%

5%

15%

1 star

15%

15%

0%

5%

Table 3.3b
Balance limits for years 2010 and 20112010-2011

Box 1:
Adult OccupantBox 2:
Child OccupantBox 3:
PedestrianBox 4:
Safety Assist

5 stars

80%

75%

40%

60%

4 stars

65%

60%

25%

40%

3 stars

35%

30%

15%

25%

2 stars

30%

25%

10%

15%

1 star

20%

15%

5%

5%

Table 3.3c
Balance limits for years 20122012

Box 1:
Adult OccupantBox 2:
Child OccupantBox 3:
PedestrianBox 4:
Safety Assist

5 stars

80%

75%60%60%

4 stars

70%60%50%

40%

3 stars

40%

30%

25%

25%

2 stars

30%25%

15%

15%

1 star

20%

15%

10%

5%

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5APPENDIX I

StartProtocols

VehicleAssessment

Assessment
Scores

WeightFactors

Calculate Weighted
Score

Overall
Weighted
Score

Calculate OverallStar Rating

Meeting
Balance
Criteria?

LimitsNo
Downgrade

Yes
Overall
RatingEnd

Figure 3.1
Flowchart for the Calculation of the Overall Star Rating
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