All definitions in § 490.101 apply to this subpart. Unless otherwise specified, the following definitions apply in this subpart:
Excessive delay means the extra amount of time spent in congested conditions defined by speed thresholds that are lower than a normal delay threshold. For the purposes of this rule, the speed threshold is 20 miles per hour (mph) or 60 percent of the posted speed limit, whichever is greater.
Peak Period is defined as weekdays from 6 a.m. to 10 a.m. and either 3 p.m. to 7 p.m. or 4 p.m. to 8 p.m. State DOTs and MPOs may choose whether to use 3 p.m. to 7 p.m. or 4 p.m. to 8 p.m.
(a) Travel time data needed to calculate the PHED measure in § 490.707(a) shall come from the travel time data set, as specified in § 490.103(e).
(b) 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 directional mainline highways of the NHS in the urbanized area(s).
(c) State DOTs shall develop hourly traffic volume data for each reporting segment as follows:
(1) State DOTs shall measure or estimate hourly traffic volumes for Peak Periods on each weekday of the reporting year by using either paragraph (c)(1)(i) or (ii) of this section.
(i) State DOTs may use hourly traffic volume counts collected by continuous count stations and apply them to multiple reporting segments; or
(ii) State DOTs may use Annual Average Daily Traffic (AADT) reported to the HPMS to estimate hourly traffic volumes when no hourly volume counts exist. In these cases the AADT data used should be the most recently available, but not more than 2 years older than the reporting period (e.g., if reporting for calendar year 2018, AADT should be from 2016 or 2017) and should be split to represent the appropriate direction of travel of the reporting segment.
(2) State DOTs shall assign hourly traffic volumes to each reporting segment by hour (e.g., between 8 a.m. and 8:59 a.m.).
(3) State DOTs shall report the methodology they use to develop hourly traffic volume estimates to FHWA no later than 60 days before the submittal of the first Baseline Performance Period Report.
(4) If a State DOT elects to change the methodology it reported under paragraph (c)(3) of this section, then the State DOT shall submit the changed methodology no later than 60 days before the submittal of next State Biennial Performance Report required in § 490.107(b).
(5) If an NHS roadway is closed, the State DOT is not required to include those time periods for the segment of road in the calculation required for this metric and measure.
(d) State DOTs shall develop annual vehicle classification data for each reporting segment using data as follows:
(1) State DOTs shall measure or estimate the percentage of cars, buses, and trucks, relative to total AADT for each segment using either paragraph (d)(1)(i) or (ii) of this section.
(i) State DOTs may use annual traffic volume counts collected by continuous count stations to estimate the annual percent share of traffic volumes for cars, buses, and trucks for each segment; or
(ii) State DOTs may use AADT reported to the HPMS to estimate the annual percent share of traffic volumes for cars, buses, and trucks, where:
(A) Buses = value in HPMS Data Item “AADT__Single__Unit”;
(B) Trucks = value in HPMS Data Item “AADT__Combination”; and
(C) Cars = subtract values for Buses and Trucks from the value in HPMS Data Item “AADT”.
(iii) If a State DOT uses the data reported to the HPMS in paragraph (d)(1)(ii) of this section, then the data values should be split to represent the appropriate direction of travel of the reporting segment.
(2) State DOTs shall report the methodology they use to develop annual percent share of traffic volume by vehicle class to FHWA no later than 60 days before the submittal of the first Baseline Performance Period Report.
(3) If a State DOT elects to change the methodology it reported under paragraph (d)(2) of this section, then the State DOT shall submit the changed methodology no later than 60 days before the submittal of next State Biennial Performance Report required in § 490.107(b).
(e) State DOTs shall develop annual average vehicle occupancy (AVO) factors for cars, buses, and trucks in applicable urbanized areas using either method under paragraph (e)(1)(i) or (ii) of this section.
(1) State DOTs shall measure or estimate annual vehicle occupancy factors for cars, buses, and trucks in applicable urbanized areas.
(i) State DOTs shall use estimated annual vehicle occupancy factors for cars, buses, and trucks in urbanized areas provided by FHWA; and/or
(ii) State DOTs may use an alternative estimate of annual vehicle occupancy factors for a specific reporting segment(s) for cars, buses, and trucks in urbanized areas, provided that it is more specific than the data provided by FHWA.
(f) All State DOTs and MPOs contributing to the unified target for the applicable area as specified in § 490.105(d)(2) shall agree to using one of the methods specified in paragraph (f)(1)(i), (ii), or (iii) of this section to identify the data that will be used to determine the Percent of Non-SOV Travel for the applicable urbanized area.
(1) The data to determine the Percent of Non-SOV Travel measure shall be developed using any one of the following methods.
(i) Method A—American Community Survey. Populations by predominant travel to commute to work may be identified from Table DP03 of the American Community Survey using the totals by transportation mode listed within the “Commuting to Work” subject heading under the “Estimate” column of the table. The “5 Year Estimate” DP03 table using a geographic filter that represents the applicable “Urban Area” shall be used to identify these populations. The Percent of Non-SOV Travel measure shall be developed from the most recent data as of August 15th of the year in which the State Biennial Performance Report is due to FHWA.
(ii) Method B—local survey. The Percent of Non-SOV Travel may be estimated from a local survey focused on either work travel or household travel for the area and conducted as recently as 2 years before the beginning of the performance period. The survey method shall estimate travel mode choice for the full urbanized area using industry accepted methodologies and approaches resulting in a margin of error that is acceptable to industry standards, allow for updates on at least a biennial frequency, and distinguish non-SOV travel occurring in the area as a percent of all work or household travel.
(iii) Method C—system use measurement. The volume of travel using surface modes of transportation may be estimated from measurements of actual use of each transportation mode. Sample or continuous measurements may be used to count the number of travelers using different surface modes of transportation. The method used to count travelers shall estimate the total volume of annual travel for the full urbanized area within a margin of error that is acceptable to industry standards and allows for updates on at least a biennial frequency. The method shall include sufficient information to calculate the amount of non-SOV travel occurring in the area as a percentage of all surface transportation travel. State DOTs are encouraged to report use counts to FHWA that are not included in currently available national data sources.
(2) State DOTs shall report the data collection method that is used to determine the Percent of Non-SOV Travel measure for each applicable urbanized area in the State to FHWA in their first Baseline Performance Period Report required in § 490.107(b)(1). The State DOT shall include sufficient detail to understand how the data are collected if either Method B or Method C are used for the urbanized area. This method shall be used for the full performance period for each applicable urbanized area.
(3) If State DOTs and MPOs that contribute to an applicable urbanized area elect to change the data collection method reported under paragraph (f)(2) of this section, then each respective State DOT shall report this change in their next Baseline Performance Report required in § 490.107(b)(1). The new method reported as a requirement of this paragraph shall not be used until the beginning of the next performance period for the Baseline Performance Report in which the method was reported to be changed.
(g) Populations of urbanized areas shall be as identified based on the most recent annual estimates published by the U.S. Census available 1 year before the State DOT Baseline Performance Period Report is due to FHWA to identify applicability of the CMAQ Traffic Congestion measures in § 490.707(a) and (b) for each performance period, as described in § 490.105(e)(8)(iii)(D) and (f)(5)(iii)(D). For computing the PHED measure in § 490.713(b), the most recent annual population estimate published by the U.S. Census, at the time when the State DOT Biennial Performance Period Report is due to FHWA shall be used.
(h) Nonattainment and maintenance area determinations for the CMAQ Traffic Congestion measures:
(1) The CMAQ Traffic Congestion measures apply to nonattainment and maintenance areas. Such areas shall be identified based on the effective date of U.S. EPA's designations under the NAAQS in 40 CFR part 81, as of the date 1 year before the State DOT Baseline Performance Period Report is due to FHWA.
(2) The nonattainment and maintenance areas to which the CMAQ Traffic Congestion measures applies shall be revised if, on the date 1 year before the State DOT Mid Performance Period Progress Report is due to FHWA, the area is no longer in nonattainment or maintenance for a criteria pollutant included in § 490.703.
(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:
Where:
Excessive Delay Threshold Travel Times = the time of travel, to the nearest whole second, to traverse the Travel Time Segment at which any longer measured travel times would result in excessive delay for the travel time segment “”;
Travel Time Segment Lengths = total length of travel time segment to the nearest thousandth of a mile for travel time reporting segment “”; and
Threshold Speeds = the speed of travel at which any slower measured speeds would result in excessive delay for travel time reporting segment “.” As defined in § 490.705, the speed threshold is 20 miles per hour (mph) or 60 percent of the posted speed limit travel time reporting segment “s,” whichever is greater.
(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
Where:
RSDs,b = travel time segment delay, calculated to the nearest whole second, for a 15-minute bin “b” of travel time reporting segment “s” for in a day in a calendar year. RSD(s)b not to exceed 900 seconds;
Travel times,b = a measured travel time, to the nearest second, for 15-minute time bin “b” recorded for travel time reporting segment “s”;
Excessive Delay Threshold Travel Times = The maximum amount of time, to the nearest second, for a vehicle to traverse through travel time segment “s” before excessive delay would occur, as specified in paragraph (c) of this section;
b = a 15-minute bin of a travel time reporting segment “s”; and
s = a travel time reporting segment.
(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:
Where:
Excessive Delays,b = excessive delay, calculated to the nearest thousandths of an hour, for 15-minute bin “b” of travel time reporting segment “s”;
RSDs,b = the calculated travel time reporting segment delay for fifteen minute bin “b” of a travel time reporting segment “s,” as described in paragraph (d)(1) of this section;
b = a fifteen minute bin of a travel time reporting segment “s”; and
s = a travel time reporting segment.
(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:
Where:
Total Excessive Delays (in person-hours) = the sum of the excessive delay, to the nearest thousandths, for all traffic traveling through single travel time reporting segment “s” on NHS within an urbanized area, specified in § 490.703, accumulated over the full reporting year;
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)
Where:
PC = the percent of cars as a share of total AADT on the segment as specified in § 490.709(d);
PB = the percent of buses as a share of total AADT on the segment as specified in § 490.709(d);
PT = the percent of trucks as a share of total AADT on the segment as specified in § 490.709(d);
AVOC = the average vehicle occupancy of cars as specified in § 490.709(e);
AVOB = the average vehicle occupancy of buses as specified in § 490.709(e); and
AVOT = the average vehicle occupancy of trucks as specified in § 490.709(e).
(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.
(a) The performance measures in § 490.707 shall be computed in accordance with this section by State DOTs and MPOs to carry out CMAQ traffic congestion performance-related requirements of this part and by FHWA to report on traffic congestion performance.
(b) The performance measure for CMAQ traffic congestion specified in § 490.707, Annual Hours of Peak Hour Excessive Delay Per Capita (the PHED measure), shall be computed to the nearest tenth, and by summing the PHED metrics of all reporting segments in each of the urbanized area, specified in § 490.703, and dividing it by the population of the urbanized area to produce the PHED measure. The equation for calculating the PHED measure is as follows:
Where:
Annual Hours of Peak Hour Excessive Delay per Capita = the cumulative hours of excessive delay, to the nearest tenth, experienced by all people traveling through all reporting segments during peak hours in the applicable urbanized area for the full reporting calendar year;
s = travel time reporting segment within an urbanized area, specified in § 490.703;
T = total number of travel time reporting segments in the applicable urbanized area;
Total Population = total hours of excessive delay in § 490.711(e) for all people traveling through travel time reporting segment “s” during a calendar year (as defined in § 490.711(f)); and
Total Population = the total population in the applicable urbanized area from the most recent annual population published by the U.S. Census at the time that the State Biennial Performance Period Report is due to FHWA.
(c) Calculation for the PHED measure, described in paragraph (b) of this section, and target establishment for the measure shall be phased-in under the requirements in § 490.105(e)(8)(vi) and (f)(5)(vi).
(d) The performance measure for CMAQ traffic congestion specified in § 490.707(b), Percent of Non-SOV Travel, shall be computed as specified in paragraphs (d)(1) through (3) of this section corresponding to the method reported by the State DOT to collect travel data for the applicable area under § 490.709(f)(2).
(1) Method A—American Community Survey. The Percent of Non-SOV Travel shall be calculated to the nearest tenth of a percent using the following formula:
Percent of Non-SOV Travel = 100% − % SOV
Where:
Percent of Non-SOV Travel = percent of commuting working population, to the nearest tenth of a percent, that predominantly do not commute by driving alone in a car, van, or truck, including travel avoided by telecommuting; and
% SOV = percent estimate for “Car, truck, or van—drive alone”.
(2) Method B—local survey. The Percent of Non-SOV Travel shall be calculated using the data derived from local survey results as specified in § 490.709(f)(1)(ii). The Percent of Non-SOV Travel measure shall be calculated to represent travel that is not occurring by driving alone in a motorized vehicle, including travel avoided by telecommuting, as a percentage of all surface transportation occurring in the applicable area. The Percent of Non-SOV Travel measure shall be calculated to the nearest tenth of a percent.
(3) Method C—system use measurement. The Percent of Non-SOV Travel shall be calculated to the nearest tenth of a percent from the data collected from system use measurements as specified in § 490.709(f)(1)(iii) using the general form of the following formula:
Where:
Percent of Non-SOV Travel = percentage of travel, to the nearest tenth of a percent, that is not occurring by driving alone in a motorized vehicle, including travel avoided by telecommuting
Volumenon-SOVVolume = Annual volume of person travel occurring while driving alone in a motorized vehicle; and
VolumeSOV = Annual volume of person travel occurring on modes other than driving alone in a motorized vehicle, calculated as:
Where:
m = travel mode (modes other than driving alone in a motorized vehicle, including travel avoided by telecommuting);
Volume m = annual volume of person travel for each mode, “m”; and
t = total number of modes that are not driving alone in a motorized vehicle.