Effective May 20, 2017, FHWA established measures to assess performance of the National Highway System6, freight movement on the Interstate system7, and the Congestion Mitigation and Air Quality Improvement (CMAQ) Program8. This third FHWA performance measure rule (PM3) established six performance measures, described below.
National Highway System Performance:
- Percent of person-miles on the Interstate system that are reliable;
- Percent of person-miles on the non-Interstate NHS that are reliable;
Freight Movement on the Interstate:
- Truck Travel Time Reliability Index (TTTR);
Congestion Mitigation and Air Quality Improvement (CMAQ) Program:
- Annual hours of peak hour excessive delay per capita (PHED);
- Percent of non-single occupant vehicle travel (Non-SOV); and
- Cumulative two-year and four-year reduction of on-road mobile source emissions for CMAQ funded projects (CMAQ Emission Reduction).
The CMAQ performance measures apply to states and MPOs with projects financed with CMAQ funds whose boundary contains any part of a nonattainment or maintenance area for ozone, carbon monoxide or particulate matter. The Columbus-Phenix City Transportation Study MPO meets air quality standards, therefore, the CMAQ measures do not apply and are not reflected in the System Performance Report.
System Performance Measures
The two System Performance measures assess the reliability of travel times on the Interstate or non-Interstate NHS system. The performance metric used to calculate reliability is the Level of Travel Time Reliability (LOTTR). LOTTR is defined as the ratio of longer travel times (80th percentile) to a normal travel time (50th percentile) over all applicable roads during four time periods (AM peak, Mid-day, PM peak, and weekends) that cover the hours of 6 AM to 8 PM each day.
The LOTTR ratio is calculated for each segment of applicable roadway, essentially comparing the segment with itself. A segment is deemed to be reliable if its LOTTR is less than 1.5 during all four time periods. If one or more time periods has a LOTTR of 1.5 or above, that segment is unreliable.
The measures are expressed as the percent of person-miles traveled on the Interstate or non-Interstate NHS system that are reliable. Person-miles take into account the number of people traveling in buses, cars, and trucks over these roadway segments. To determine total person miles traveled, the vehicle miles traveled (VMT) on each segment is multiplied by average vehicle occupancy. To calculate the percent of person miles traveled that are reliable, the sum of the number of reliable person miles traveled is divided by the sum of total person miles traveled.
Freight Movement Performance Measure
The Freight Movement performance measure assesses reliability for trucks traveling on the Interstate. A TTTR ratio is generated by dividing the 95th percentile truck travel time by a normal travel time (50th percentile) for each segment of the Interstate system over five time periods throughout weekdays and weekends (AM peak, Mid-day, PM peak, weekend, and overnight) that cover all hours of the day. For each segment, the highest TTTR value among the five time periods is multiplied by the length of the segment. The sum of all length-weighted segments is then divided by the total length of Interstate to generate the TTTR Index.
PM3 Performance Targets
Performance for the PM3 measures is assessed and reported over a four-year performance period. For all PM3 measures except the CMAQ Emission Reduction measure, the first performance period began on January 1, 2018, and will end on December 31, 2021. GDOT reported baseline PM3 performance and targets to FHWA on October 1, 2018 and will report updated performance information at the midpoint and end of the performance period. The second four-year performance period will cover January 1, 2022, to December 31, 2025 with additional performance periods following every four years.
The PM3 rule requires state DOTs and MPOs to establish two-year and/or four-year performance targets for each PM3 measure. For all targets except CMAQ Emission Reductions, the current two-year and four-year targets represent expected performance at the end of calendar years 2019 and 2021, respectively.
States establish targets as follows:
- Percent of person-miles on the Interstate system that are reliable – two-year and four-year targets;
- Percent of person-miles on the non-Interstate NHS that are reliable – four-year targets;
- Truck Travel Time Reliability – two-year and four-year targets;
- Annual hours of peak hour excessive delay per capita (PHED) – four-year targets;
- Percent of non-single occupant vehicle travel (Non-SOV) – two-year and four-year targets; and
- CMAQ Emission Reductions – two-year and four-year targets.
Table 3. Statewide Baseline Performance Performance Measure | 2-Year Target | 4-Year Target |
Percent of person-miles traveled on the Interstate that is reliable | 79.9% | 68.4% |
Percent of person-miles traveled on the non-Interstate NHS that is reliable | 87.3% | 85.3% |
Truck Travel Time Reliability (TTTR) Index | 1.62 | 1.65 |
Annual Hours of Peak Hour Excessive Delay (PHED) Per Capita* | 23.7 hours | 27.2 hours |
Percent of Non-Single Occupancy Vehicle (SOV) Travel* | 22.7% | 22.7% |
Total Emissions Reduction | VOC: 157.200 kg/day; NOx: 510.900 kg/day | VOC: 257.100 kg/day; NOx: 904.200 kg/day |
*GDOT, Atlanta Regional Commission and Cartersville-Bartow Metropolitan Planning Organization are required to establish and report single targets for Annual Hours of Peak Hour Excessive Delay (PHED) Per Capita and Percent of Non-Single Occupancy Vehicle (SOV) Travel for Atlanta urbanized area.
MPOs establish four-year targets for the System Performance and Freight Movement. MPOs establish targets by either agreeing to program projects that will support the statewide targets or setting quantifiable targets for the MPO’s planning area that differ from the state targets.
GDOT established statewide PM3 targets on May 16, 2018. The Columbus-Phenix City Transportation Study (MPO) adopted/approved the Georgia statewide PM3 targets on June 19, 2018. Table 6 presents statewide baseline performance for each PM3 measure as well as the current two-year and four-year statewide targets established by GDOT.
On or before October 1, 2020, GDOT will provide FHWA a detailed report of PM3 performance covering the period of January 1, 2018, to December 31, 2019. GDOT and the Columbus-Phenix City Transportation Study (MPO) will have the opportunity at that time to revisit the four-year PM3 targets. The Columbus-Phenix City Transportation Study (MPO) will adopt the Georgia Department of Transportations PM 3 targets on May 16, 2023.
The Columbus-Phenix City Transportation Study (MPO) recognizes the importance of linking goals, objectives, and investment priorities to stated performance objectives, and that establishing this link is critical to the achievement of national transportation goals and statewide and regional performance targets. As such, the FY 2021 - 2024 TIP planning process directly reflects the goals, objectives, performance measures, and targets as they are available and described in other State and public transportation plans and processes; specifically, the Georgia Statewide Freight and Logistics Action Plan, the current 2045 Georgia Statewide Transportation Plan (SWTP), and the Columbus-Phenix City Transportation Study (MPO) 2045 Metropolitan Transportation Plan (MTP).
- GDOT’s Statewide Freight and Logistics Action Plan defines the conditions and performance of the state freight system and identifies the policies and investments that will enhance Georgia’s highway freight mobility well into the future. The Plan identifies freight needs and the criteria Georgia will use to determine investments in freight, and prioritizes freight investments across modes.
- The GDOT SWTP summarizes transportation deficiencies across the state and defines an investment portfolio across highway and transit capacity, highway preservation, highway safety, and highway operations over the 25-year plan horizon. Investment priorities reflect optimal performance impacts across each investment program given anticipated transportation revenues.
- The Columbus-Phenix City Transportation Study (MPO) 2045 MTP addresses reliability, freight movement, congestion, [and emissions], identifies needs for each of these issues within the metropolitan planning area, and allocates funding for targeted improvements.
- The Columbus-Phenix City Transportation Study (MPO) completed a corridor study on the J.R. Allen Parkway / US 80 Highway. The study addresses freight movement, congestion, and reliability. The study can be located at www.columbusga.gov/Planning/pdfs/jr-allen-parkway-final-report.pdf
To support progress towards GDOT’s statewide PM3 targets, the FY 2021-2024 TIP devotes a significant amount of resources to projects that will address passenger and highway freight reliability and delay, [reduce SOV travel, and reduce emissions].
A total of $0 has been programmed in the FY 2021-2024 TIP to address system performance; averaging approximately $0 per year.
A total of $0 has been programmed in the FY 2021-2024 TIP to address truck travel time reliability; averaging approximately $0 per year.