TABLE 2—

Percentage of Cars With All Children Younger Than 12 Years Seated in the Rear, by Income Area

	Percentage of Cars
	Preintervention	Postintervention
Holyoke	33	49a,b
High-income areas	31	51a,c
Low-income areas	35	46a
Control cities	28	41a,b
High-income areas	29	43a
Low-income areas	27	39a

^aP < .0001 for change across time periods.

^bP < .0001 differences in the changes in rates between Holyoke and control cities.

^cP < .01 for difference in effect between high-income and low-income areas.