Traffic Safety Facts

Traffic Tech – Technology Transfer Series

Number 362 February 2009

U.S. Department of Transportation 1200 New Jersey Avenue SE., Washington, DC 20590

National Highway Traffic Safety Administration

In	2004	the	National	Highway	Traffic	Safety	Administration	and	the	Bureau	of	Indian	Affairs’	Indian	Highway	Safety	Program	established	the	first	baseline	seat	

belt	use	rate	for	tribal	reservations	subject	to	tribal	law	

and	 tribal	 traffic	 law	 enforcement.	 The	 methodology	

was	 similar	 to	 NHTSA’s	 National	 Occupant	 Protection	Usage	Survey	(NOPUS),	which	uses	a	probabilitybased	survey	to	report	a	single	seat	belt	use	rate	to	the	

Nation.	Because	less	than	a	third	of	the	562	federally	

recognized	tribal	governments	in	the	United	States	are	

subject	 to	 tribal	 law	 and	 tribal	 law	 enforcement,	 this	

estimate	of	seat	belt	use	for	Native	American	tribal	reservations	 computes	 a	 single	 seat	 belt	 use	 rate	 for	 the	

180	tribal	reservations	where	Native	Americans	enforce	

their	 own	 traffic	 laws.	 In	 2006	 NHTSA	 administered	

this	survey	for	a	second	time.	

Methods

The	sampling	plan	for	the	2006	Native	American	tribal	

reservation	 seat	 belt	 survey	 was	 first	 developed	 and	

implemented	in	2004.	It	provides	a	reliable	estimate	of	

belt	use	across	all	the	tribal	reservations	subject	to	tribal	

law	 and	 tribal	 traffic	 law	 enforcement.	 The	 sampling	

procedure	weighted	all	tribal	reservations	proportional	

to	their	populations,	and	included	the	criteria	that	the	

sample	of	the	tribal	reservations:

n	 be	limited	to	tribal	reservations	with	populations	of	

2,000	or	more	(n=61);	

n	 represent	varying	road	conditions;

n	 provide	representation	of	the	6	BIA-defined	Native	

American	areas;	and

n	 include	enough	sites	per	reservation	so	that	the	final	

combined	seat	belt	use	rate	would	be	reliable.

The	objective	was	to	sample	approximately	1	in	4	reservations,	 or	 one	 reservation	 per	 30,000	 population.	

The	planned	sample	included	18	reservations	with	150	

sites	on	these	reservations.	However,	the	Navajo	reservation	 in	 the	 Southwest,	 which	 has	 22	 percent	 of	 the	

total	Native	American	population,	did	not	permit	seat	

belt	 observations	 on	 its	 territory.	 Ultimately,	 NHTSA	

collected	data	from	120	sites	on	16	tribal	reservations.	

This	was	true	for	both	the	initial	study	and	this	subsequent	replication.	Seat	belt	use	was	observed	between	

September	and	December	2006	(15	reservations)	and	in	

March	2007	(one	reservation).	All	results	were	weighted	

across	tribal	areas	to	account	for	the	reservation	selection	approach.	Overall,	12,778	drivers	and	passengers	

were	observed.

Results

For	the	tribal	reservations	subject	to	tribal	law	and	tribal	

traffic	 law	 enforcement,	 the	 overall	 seat	 belt	 use	 rate	

was	61.8	percent.	This	represents	a	significant	increase	

of	6.4	percentage	points	from	the	2004	seat	belt	rate	of	

55.4	percent.	

Seat Belt Use by Law Type and Year of Observation

2004 2006

Belt

Use N

Belt

Use N

Reservation Law Type:

Primary 68.6% 7,976 73.1% 8,810

Secondary 53.2% 2,096 59.3% 2,197

None 26.4% 1,876 32.7% 1,771

Surrounding State Law Type:

Primary 72.8% 8,054 75.0% 9,218

Secondary 33.3% 3,894 45.0% 3,560

There	continues	to	be	a	very	high	variation	in	belt	use	

across	reservations.	In	2004,	belt	use	ranged	from	a	low	

of	8.8	percent	to	a	high	of	84.8	percent.	This	variability	

decreased	by	16	percentage	points	by	2006,	when	seat	

belt	use	on	reservations	ranged	from	a	low	of	28	percent	to	a	high	of	88	percent.	

2006 Seat Belt Use Estimate for Native 

 American Tribal Reservations
TRAFFIC TECH	is	a	publication	to	disseminate	information	about	

traffic	 safety	 programs,	 including	 evaluations,	 innovative	 programs,	and	new	publications.	Feel	free	to	copy	it	as	you	wish.	If	

you	would	like	to	receive	a	copy,	contact	Dr.	Angela	Eichelberger,	

Editor:	fax	202-366-7394,	or	e-mail	traffic.tech@dot.gov.

1200	New	Jersey	Avenue	SE.,	NTI-130

Washington,	DC	20590

Seat	belt	use	differed	according	to	vehicle	type	and	sex	

of	the	drivers	and	passengers.	The	seat	belt	use	patterns	

were	consistent	with	the	2004	survey	of	Native	American	tribal	reservations	as	well	as	results	from	other	State	

and	national	seat	belt	surveys.	Seat	belt	use	rates	were	

higher	for	cars	(62.4%),	SUVs	(67.2%),	and	vans	(69.5%)	

and	lower	for	pickup	trucks	(55.8%).	

Males	 wore	 seat	 belts	 less	 than	 females,	 58.4	 percent	

versus	66.3	percent.	More	drivers	(62.9%)	than	passengers	(58.5%)	wore	seat	belts.	Overall,	the	lowest	belt	use	

rate	was	for	male	passengers	in	pickups,	(48.6%)	while	

the	highest	rate	was	for	female	drivers	of	vans	(74%).

Seat	belt	use	also	varied	consistently	with	road	type.	On	

collector	roads	in	towns,	belt	use	was	63.7	percent,	while	

on	between-town	rural	arterials	belt	use	was	59.7	percent.	Three	BIA	regions	had	multiple	reservations.	The	

Northern	Plains	reservations	had	five	of	the	lowest	six	

belt	use	rates	and	collectively	averaged	just	38.9	percent	

belt	use.	Great	Lakes	and	Northwest	had	the	highest	

belt	use;	two	of	the	four	reservations	in	those	two	areas	

had	the	highest	individual	belt	use	rates	observed.	Of	

the	five	reservations	in	the	Southwest,	three	had	moderate	belt	use,	while	two	reservations	had	rates	above	

70	and	80	percent	respectively,	which	were	among	the	

higher	rates	for	tribal	reservations.

Within	the	sample,	the	9	reservations	with	primary	seat	

belt	laws	had	73.1	percent	of	vehicle	occupants	wearing	

seat	belts.	By	comparison,	the	3	tribal	reservations	that	

had	secondary	belt	laws	averaged	59.3	percent	belt	use,	

and	the	4	reservations	with	no	belt	use	laws	of	any	kind	

averaged	only	37.2	percent	belt	use.	

In	addition,	9	reservations	were	located	in	States	with	

primary	belt	use	laws.	Eight	of	those	9	reservations	had	

the	 highest	 use	 rates;	 overall,	 the	 9	 averaged	 75	 percent	belted	occupants.	The	remaining	7	reservations,	in	

States	with	secondary	belt	use	laws,	were	among	the	

lowest-usage	reservations	that	averaged	just	45	percent	

buckled	occupants.	

Conclusions

Many	factors	may	have	contributed	to	increasing	belt	

use	 on	 the	 Native	 American	 reservations	 subject	 to	

tribal	law	and	tribal	traffic	enforcement.	Messages	from	

other	NHTSA	high-visibility	seat	belt	enforcement	campaigns,	such	as	the	Click It or Ticket mobilization	and	the	

Buckle Up in Your Truck and	Rural	Seat	Belt	demonstration	projects,	which	occurred	off	the	reservations,	may	

have	affected	driving	behaviors	on	the	reservations.	

Both	the	first	and	second	Native	American	tribal	reservation	 seat	 belt	 surveys	 found	 that	 the	 tribal	 reservations	with	the	highest	belt	use	rates	had	usage	rates	

comparable	to	general	U.S.	belt	use	rates,	which	means	

that	Native	American	governments	can	be	effective	in	

achieving	 high	 levels	 of	 belt	 use.	 The	 low	 belt	 usage	

rates	on	other	tribal	reservations	suggest	that	their	governments	have	done	little	or	nothing	toward	achieving	

high	belt	use.	Reservations	with	primary	seat	belt	laws	

typically	had	the	highest	use	rates,	followed	by	reservations	with	secondary	seat	belt	laws.	Reservations	with	

no	seat	belt	laws	had	the	lowest	use	rates.	Tribal	policy	

and	procedures	are	likely	responsible	for	current	levels	

of	seat	belt	use,	and	it	is	in	these	areas	that	tribal	efforts	

can	 be	 most	 effective	 in	 establishing	 and	 improving	

seat	belt	usage	levels.

How to Order

To	order	2006 Seat Belt Use Estimate for Native American 

Tribal Reservations (15	 pages,	 plus	 appendices),	 prepared	by	Preusser	Research	Group,	write	to	the	Office	

of	Behavioral	Safety	Research,	NHTSA,	NTI-132,	1200	

New	Jersey	Avenue	SE.,	Washington,	DC	20590,	fax	202-

366-7394,	or	download	from	www.nhtsa.dot.gov.	John	

Siegler,	Ph.D.,	was	the	Contracting	Officer’s	Technical	

Representative	for	this	project.