222.47—What periodic updates are required?

(a) Quiet zones with SSMs at each public crossing. This paragraph addresses quiet zones established pursuant to §§ 222.39(a)(1), 222.41(a)(1)(i), and 222.41(b)(1)(i) (quiet zones with an SSM implemented at every public crossing within the quiet zone) of this part. Between 4 1/2 and 5 years after the date of the quiet zone establishment notice provided by the public authority under § 222.43 of this part, and between 4 1/2 and 5 years after the last affirmation under this section, the public authority must:
(b) Quiet zones which do not have a supplementary safety measure at each public crossing. This paragraph addresses quiet zones established pursuant to §§ 222.39(a)(2) and (a)(3), § 222.39(b), §§ 222.41(a)(1)(ii), (a)(1)(iii), and (a)(1)(iv), and §§ 222.41(b)(1)(ii), (b)(1)(iii), and (b)(1)(iv) (quiet zones which do not have an SSM at every public crossing within the quiet zone) of this part. Between 2 1/2 and 3 years after the date of the quiet zone establishment notice provided by the public authority under § 222.43 of this part, and between 2 1/2 and 3 years after the last affirmation under this section, the public authority must: