It would be interesting to see a state law.

From an NTSB 2014 Tire Safety Symposium (Dec 9-10 2014) "Tire Aging and Service Life":

States Consider Regulations
• Several states have considered bills to regulate tire
age
— Most related to customer notification of tire aging / tire age at
point of sale.
— One bill proposed tires 6 years or older could not pass annual
state safety inspections.
• None have advanced.


http://www.ntsb.gov/news/events/Pages/2014_Tire_Safety_SYM_agenda.aspx
http://www.ntsb.gov/news/events/Documents/2014_Tire_Safety_SYM_Panel_4b_Kane.pdf