23 C.F.R. § 490.309
(b) State DOTs shall collect data in accordance with the following relevant HPMS requirements to report IRI, rutting (asphalt pavements), faulting (jointed concrete pavements), and Cracking percent. State DOTs will be permitted to report present serviceability rating (PSR) for specific locations in accordance with the HPMS requirements as an alternative where posted speed limits are less than 40 miles per hour.
(1) For the Interstate System the following shall apply for all the pavement condition metrics:
(i) State DOTs shall collect data—
(iv) For the portions of the Interstate mainline highway pavements where posted speed limits are less than 40 MPH (e.g., border crossings, toll plazas), State DOTs may collect and report the Present Serviceability Rating (PSR) as an alternative to the IRI, Cracking__Percent, rutting, and faulting in this pavement section and shall follow the following requirements:
(2) For the non-Interstate NHS the following shall apply:
(i) For the IRI metric, State DOTs shall collect and report data:
(ii) For the Cracking percent, rutting and faulting metrics, State DOTs shall collect data—
(iii) For the portions of mainline highways where posted speed limits of less than 40 MPH, State DOTs may collect the Present Serviceability Rating (PSR) as an alternative to the IRI, Cracking__Percent, rutting, and faulting pavement condition metrics, in paragraphs (b)(2)(i) and (ii) of this section, and shall follow the following requirements:
(3) Data collection methods for each of the condition metrics shall conform to the following:
(vi) For asphalt pavements, the method to collect data needed to determine the rutting metric shall either be:
(c) State DOTs shall collect data in accordance with the following relevant HPMS requirements to report Through Lanes, Surface Type, and Structure Type.
(1) State DOTs shall collect data: