The National Highway Traffic Safety Administration recently released 2008 data on State seat belt usage.

The Best State for Seatbelt Usage is Michigan with a 97.2% usage.  The other top 5 Best States are Hawaii, Washington, Oregon and California. 

The Worst State for Seatbelt Usage is Massachusetts with only a 66.8% usage.  The other Worst 5 States are Wyoming, New Hampshire, Arkansas and Mississippi. 

These stats tend to get wide publicity and embolden states to take more action against citizens who do not use seat belts.

22 states do not allow police officers to stop motorists for not wearing a seat belt.  Primary States, those that allow stopping drivers for no seat belts, tend to have the highest seat belt usage. 

According to a 2001 study of US crash data, it was found that previous estimates of seat belt effectiveness had been significantly overstated. According to the analysis used, seat belts were claimed to have decreased fatalities by 1.35% for each 10% increase in seat belt use.  Many drivers would prefer not to be pulled over for lack of seat belt usage.  Should we be asking our limited police departments to pull over drivers for not using seat belts? Are there more important "crimes" that our police should be pursuing?  Are drivers in Massachusetts that much more dangerous than Michigan?
See:

'The Effects of Mandatory Seat Belt Laws on Driving Behavior and Traffic Fatalities' by Alma Cohen and Liran Einav at Harvard Law School
	State	Seat Belt use	%Change
1	Michigan	97.20%	3.50%
2	Hawaii	97.00%	-0.60%
3	Washington	96.50%	0.10%
4	Oregon	96.30%	1.00%
5	California	95.70%	1.10%
6	Maryland	93.30%	0.20%
7	Iowa	92.90%	1.60%
8	New Jersey	91.80%	0.40%
9	Delaware	91.30%	4.70%
10	Indiana	91.20%	3.30%
11	Texas	91.20%	-0.60%
12	New Mexico	91.10%	-0.40%
13	Nevada	90.90%	-1.30%
14	Illinois	90.50%	0.40%
15	Dist. Of Columbia	90.00%	2.90%
16	North Carolina	89.80%	1.00%
17	Georgia	89.60%	0.60%
18	West Virginia	89.50%	-0.10%
19	New York	89.10%	5.60%
20	Connecticut	88.00%	2.20%
21	Vermont	87.30%	0.20%
22	Minnesota	86.70%	-1.10%
23	Alabama	86.10%	3.80%
24	Utah	86.00%	-0.80%
25	Pennsylvania	85.10%	-1.60%
26	Alaska	84.90%	2.50%
27	Oklahoma	84.30%	1.20%
28	Maine	83.00%	3.20%
29	Nationwide	83%	1%
30	Ohio	82.70%	1.10%
31	Montana	82.60%	3.90%
32	Colorado	81.70%	0.60%
33	Florida	81.70%	2.60%
34	North Dakota	81.60%	-0.60%
35	Tennessee	81.50%	1.30%
36	Virginia	80.60%	0.70%
37	Arizona	79.90%	-1.00%
38	South Carolina	79.00%	4.50%
39	Kansas	77.40%	2.40%
40	Idaho	76.90%	-1.60%
41	Missouri	75.80%	-1.40%
42	Louisiana	75.50%	0.30%
43	Wisconsin	74.20%	-1.10%
44	Kentucky	73.30%	1.50%
45	Rhode Island	72.00%	-7.10%
46	South Dakota	71.80%	-1.20%
47	Mississippi	71.30%	-0.50%
48	Arkansas	70.40%	0.50%
49	New Hampshire	69.20%	5.40%
50	Wyoming	68.60%	-3.60%
51	Massachusetts	66.80%	-1.90%

Source:  National Highway Traffic Safety Administration Blog Search Engine