(a) The performance metric required to calculate the measure specified in §490.707(a) is Total Peak Hour Excessive Delay (person-hours)(referred to as the PHED metric). The following paragraphs explain how to calculate this PHED metric.

(b) State DOTs shall use the following data to calculate the PHED metric:

(1) Travel times of all traffic (“all vehicles” in NPMRDS nomenclature) during each 15 minute interval for all applicable reporting segments in the travel time data set occurring for peak periods from January 1st through December 31st of the same year;

(2) The length of each applicable reporting segment, reported as required under §490.709(b);

(3) Hourly volume estimation for all days and for all reporting segments where excessive delay is measured, as specified in §490.709(c);

(4) Annual vehicle classification data for all days and for all reporting segments where excessive delay is measured, as specified in §490.709(d); and

(5) Annual vehicle occupancy factors for cars, buses, and trucks for all days and for all reporting segments where excessive delay is measured, as specified in §490.709(e).

(c) The State DOT shall calculate the “excessive delay threshold travel time” for all applicable travel time segments as follows:

(d) State DOTs shall determine the “excessive delay” for each 15 minute bin of each reporting segment for every hour and every day in a calendar year as follows:

(1) The travel time segment delay (RSD) shall be calculated to the nearest whole second as follow:

RSDs,b − Excessive Delay Threshold Travel Times and RSDs,b ≤ 900 seconds

(2) Excessive delay, the additional amount of time to traverse a travel time segment in a 15-minute bin as compared to the time needed to traverse the travel time segment when traveling at the excessive delay travel speed threshold, shall be calculated to the nearest thousandths of an hour as follows:

(e) State DOTs shall use the hourly traffic volumes as described in §490.709(c) to calculate the PHED metric for each reporting segment as follows:

AVO = Average Vehicle Occupancy;

s = a travel time reporting segment;

d = a day of the reporting year;

TD = total number of days in the reporting year;

h = single hour interval of the day where the first hour interval is 12 a.m. to 12:59 a.m.;

TH = total number of hour intervals in day “h”;

b = 15-minute bin for hour interval “h”;

TB = total number of 15-minute bins where travel times are recorded in the travel time data set for hour interval “h”;

Excessive Delays,b,h,d = calculated excessive travel time, in hundredths of an hour, for 15 minute bin (), hour interval (h), day (d), and travel time segment (s), as described in paragraph (d)(2) of this section; and

Where the equation equals hourly traffic volume, to the nearest tenth, for hour interval “h” and day “d” that corresponds to 15-minute bin “b” and travel time reporting segment “s” divided by 4. For example, the 9 a.m. to 9:15 a.m. minute bin would be assigned one fourth of the hourly traffic volume for the 9 a.m. to 9:59 a.m. hour on the roadway in which travel time segment is included;

AVO = (PC × AVOC) + (PB × AVOB) + (PT × AVOT)

(f) Starting in 2018 and annually thereafter, State DOTs shall report the PHED metric (to the nearest one hundredth hour) in accordance with HPMS Field Manual by June 15th of each year for the previous year's PHED measures. The PHED metric shall be reported for each reporting segment. All reporting segments of the NPMRDS shall be referenced by NPMRDS TMC or HPMS section(s). If a State DOT elects to use, in part or in whole, the equivalent data set, all reporting segments shall be referenced by HPMS sections.