safety belt statistics - rear seat 2007

Safety belt wearing by adult rear seat passengers: Results of national survey, November/December 2007

The latest annual national survey of safety belt use in New Zealand by adults in the rear seats of cars was carried out in November and December 2007. A small number of sites were surveyed in February 2008 due to data collection issues. More than 9,000 adults seated in the rear seat of cars were observed at 139 sites around the country. As in previous years, each site was surveyed between 2 p.m. and 4 p.m. on Sunday afternoons during the school term. Only adults seated in the rear window positions were included in the survey.

In 2007, the safety belt wearing rate for rear seat adult passengers was 87%. This result is slightly lower than in 2006 and is similar to 2004 and 2005 wearing rates (see Table 1).

Table 1. Safety belt wearing rates for adults in the rear seat (%)

Category	2000	2001	2002	2003	2004	2005	2006	2007
Males	72	66	76	78	82	84	86	84
Females	79	73	83	84	88	89	91	90
Van passengers	67	50	69	72	72	75	79	75
New Zealand	76	70	80	81	86	86	89	87

Female rear seat passengers continued to have a higher rear seat safety belts wearing rate than males (see Table 1). All adult passengers had a lower wearing rate in vans. Rear seat passengers who appeared to be aged 15-19 years were recorded as teenagers. The wearing rate among teenagers was 85%. More teenage girls were wearing their safety belts (86%) than teenage boys (83%). These are similar to the corresponding adult rates, but slightly lower.

Figure 1. Safety belt wearing rates for adults in the rear seat, 1998-2007

Regional Wearing Rates

National restraint wearing surveys are designed to provide a consistent measure of safety belt use over time, by surveying the same sites in each region each year. In 2007, at least 200 vehicle occupants were surveyed in each region, except in Gisborne where 167 people were surveyed and West Coast where 145 people were surveyed.

Table 2 shows the rear seat safety belt wearing rates in each Local Government region over the last ten years. Overall, the wearing of rear seat safety belts has decreased slightly. Waikato and Canterbury showed the greatest statistically significant improvements in 2007. Northland, Bay of Plenty, and Otago all decreased significantly. Southland improved on its wearing rate for 2006, back up to approximately 2005 levels.

Wearing rates in all other regions have not changed markedly since last year, and are continuing to follow a similar pattern to the national wearing rate.

Table 2. Rear seat adult safety belt wearing rates by region (%)

Local Government Region	2000	2001	2002	2003	2004	2005	2006	2007
Northland	88	72	84	87	89	94	99	71
Auckland	84	84	84	82	90	82	93	92
Waikato	78	80	78	82	85	83	83	88
Bay of Plenty	66	53	79	70	78	85	90	76
Gisborne	53	55	54	69	59	97	86	92
Hawkes Bay	47	52	81	76	87	96	90	84
Taranaki	66	65	81	83	81	92	91	93
Manawatu-Wanganui	83	73	79	85	85	87	94	92
Wellington	78	71	77	82	87	84	89	87
Nelson-Marlborough	85	82	77	90	93	89	88	87
West Coast	75	82	79	78	85	89	95	91
Canterbury	76	58	76	82	88	85	87	91
Otago	87	85	88	79	78	88	92	84
Southland	74	76	67	88	74	70	64	71
All NZ	76	70	80	81	86	86	89	87

Note. The accuracy of the wearing rates shown here depends on the sample sizes (the number of car occupants observed). If the sample size is small, the data may show large random fluctuations in the observed wearing rate.

Territorial Local Authority Wearing Rates

At Local Authority level, sample sizes are relatively small and results should be treated with caution. For example, with a sample size of 100 and a wearing rate of 75% the margin of error¹ is approximately 9%. While small samples make it difficult to detect small changes in the wearing rate from year to year, these results are useful as an indication of how much improvement is needed. No wearing rate has been estimated where fewer than 80 people were sampled.

Table 3. Rear seat adult safety belt wearing rates by Territorial Local Authority (%)

Local authority/ authorities	People in sample	Wearing rate 2007
Northland
Far North	117	80
Whangarei	196	67
Whangarei/Kaipara	232	67
Auckland
North Shore	251	96
Rodney	296	98
Waitakere	148	93
Auckland	234	97
Manukau	291	77
Papakura	141	94
Franklin	67	Sample too small
Waikato
Thames-Coromandel / Hauraki	165	95
Waikato	263	79
Hamilton City	345	82
Matamata-Piako	51	Sample too small
Waipa	220	92
South Waikato	307	99
Waitomo	100	83
Otorohanga	128	89
Taupo	238	89
Bay of Plenty / Gisborne
Tauranga	158	84
Western Bay of Plenty	137	90
Rotorua	237	64
Whakatane / Opotiki / Kawerau	151	74
Gisborne
Gisborne	167	92
Hawkes Bay
Hastings / Napier² / Central Hawkes Bay	131	92
Wairoa	105	74
Taranaki
New Plymouth	449	92
Stratford	92	97
South Taranaki	91	97
Manawatu-Wanganui
Rangitikei / Ruapehu / Wanganui	189	86
Manawatu	117	93
Palmerston North	261	95
Tararua / Horowhenua	129	91
Wellington
Kapiti Coast	267	98
Porirua	76	95
Upper Hutt	129	84
Hutt	153	71
Wellington City	75	80
Masterton	176	85
Carterton / South Wairarapa	169	88
Nelson-Marlborough / Tasman
Nelson	88	88
Marlborough	100	82
Tasman	113	90
West Coast
Buller	23	Sample too small
Grey	88	86
Buller / Grey / Westland	145	91
Canterbury
Kaikoura	115	74
Hurunui	88	100
Waimakariri	98	91
Christchurch City	226	83
Selwyn	180	99
Ashburton	86	99
Timaru	143	97
Mackenzie / Waimate	90	93
Otago
Waitake	101	89
Central Otago	82	70
Queenstown-Lakes	167	72
Dunedin	155	98
Clutha	71	Sample too small
Southland
Gore	133	70
Invercargill / Southland	105	73

Police District Wearing Rates

National restraint wearing surveys are designed to provide a consistent measure of safety belt use over time, by surveying the same sites in each Police District each year. In 2007, at least 220 vehicle occupants were surveyed in each district. Table 4 shows the rear safety belt wearing rates in each Police District over the last ten years.

Overall, rear safety belt wearing stayed relatively constant in 2007. Northland and Bay of Plenty Police Districts showed a decrease in rear safety belt wearing. Canterbury showed an increase in wearing rate. Wearing rates in all other police districts were approximately constant over the last year.

Table 4. Rear seat adult safety belt wearing rates by Police District (%)

Police District	2000	2001	2002	2003	2004	2005	2006	2007
Northland	88	72	84	87	89	94	99	71
Waitemata	90	94	85	82	93	91	96	96
Auckland	79	72	78	87	80	72	98	97
Counties Manukau	73	79	86	78	89	70	83	83
Waikato	77	80	79	81	85	83	84	86
Bay of Plenty	72	60	79	74	81	85	88	84
Eastern	49	53	77	75	84	96	89	87
Central	75	68	80	85	84	89	93	92
Wellington	78	71	77	82	87	84	89	87
Tasman	79	82	74	89	91	88	89	85
Canterbury	76	58	78	81	87	85	87	93
Southern	81	59	81	82	77	83	84	81
All NZ	76	70	80	81	86	86	89	87

Police Area Wearing Rates

Sample sizes for many Police Areas are relatively small compared to those for Police Districts and results should be treated with caution. For example, with a sample size of 150 and a wearing rate of 75% the margin of error¹ is approximately 7%. While a sample as small as this makes it difficult to detect small changes in the wearing rate from year to year, these results are useful as an indication of how much improvement is needed. No wearing rate has been estimated where fewer than 80 people were sampled.

Table 5. Rear seat adult safety belt wearing rates by Police Area (%)

Police Area	People in sample	Wearing rate 2007
Northland
Far North	117	80
Whangarei	232	67
North Shore / Waitakere
North Shore	251	96
Waitakere	148	93
Rodney	296	98
Auckland
Auckland	234	97
Counties Manukau
Manukau West	149	76
Manukau Central	142	77
Manukau South	208	93
Waikato
Hamilton	345	82
Waikato East	216	94
Waikato West	711	86
Bay of Plenty
Western Bay of Plenty	295	86
Eastern Bay of Plenty	151	74
Rotorua	237	64
Taupo	545	94
Eastern
Gisborne	272	85
Napier	42	Sample too small
Hastings	89	97
Central
New Plymouth	449	92
Taranaki rural	183	97
Wanganui	61	Sample too small
Ruapehu	65	Sample too small
Wanganui/ Ruapehu	126	87
Palmerston North City	261	95
Palmerston North rural	246	92
Wellington
Kapiti-Mana	343	97
Wellington	75	80
Lower Hutt	153	71
Upper Hutt	129	84
Wairarapa	345	86
Tasman
Nelson Bays	201	89
Marlborough	215	78
West Coast	145	91
Canterbury
Northern Canterbury	186	95
Christchurch Central	121	68
Southern Canterbury	233	95
Mid-South Canterbury	371	99
Southern
Dunedin	226	97
Otago Rural	350	76
Southland	238	71

¹Margin of error such that wearing rate +- margin of error describes a 95% confidence interval for the wearing rate.
²Sample sizes in the Napier and Hastings areas were reduced due to survey problems in 2007. Full surveys will be obtained in 2008.