(a) Travel time data needed to calculate the Travel Time Reliability measures in § 490.507(a) shall come from the travel time data set, as specified in § 490.103(e).

(1) State DOTs, in coordination with MPOs, shall define reporting segments in accordance with § 490.103(f). Reporting segments must be contiguous so that they cover the full extent of the mainline highways of the NHS in the State.

(2) [Reserved]

(b) State DOTs shall not replace missing travel times when data are not available in the travel time data set (data not reported, or reported as “0” or null) as specified in § 490.511(b)(1)(v).

(c) AADT needed to calculate the Travel Time Reliability measures will be used, as reported to HPMS in June of the reporting year, to assign an annual volume to each reporting segment. Annual volume will be calculated as:

(d) The average occupancy factors for the State and/or metropolitan area (as applicable) needed to calculate Travel Time Reliability measures shall come from the most recently available data tables published by FHWA unless using other allowed data source(s).

(e) If an NHS roadway is closed, the State DOT is not required to include those time periods for those segments of road in the calculations required for the Level of Travel Time Reliability (LOTTR) metric (see § 490.511(a)(1)).

(f) The FHWA will post on the FHWA website, no later than August 15th of each reporting year, the CO2 factors for each on-road fuel type that will be used to calculate the GHG metric for the GHG measure in § 490.105(c)(5).

(g) Fuel sales information needed to calculate the fuel consumed for the GHG measure in § 490.507(b) shall:

(1) Represent the total number of gallons of fuel consumed by fuel type; and

(2) Be based on fuels sales data for the prior calendar year, and reported to Fuels & FASH.

(h) Annual vehicle miles traveled (VMT) needed to calculate the GHG measure in § 490.507(b) shall come from the best available data that represents the prior calendar year and is consistent, to the maximum extent practicable, with data submitted to HPMS. The VMT data needed to calculate the GHG metric in § 490.511(c) for the reference year, shall be the HPMS data as of November 30, 2023.