System Performance

State Departments of Transportation (DOTs) must establish statewide targets for the performance of the Interstate and non-Interstate National Highway System (NHS) during four peak travel time periods which include peak daytime periods and weekend periods. Each state sets its performance targets for the Level of Travel Time Reliability (LOTTR) Index which indicates the reliability of travel on the Interstate and non-Interstate NHS. A road segment is considered reliable if the ratio of the 80th percentile peak hour travel time to the normal peak hour travel time (50th percentile) is less than 1.5. The measure also incorporates vehicle occupancy to identify the person miles traveled on the system. LOTTR targets are established for the entire state that reflect the person miles traveled on road segments that are considered reliable. Two- and four-year targets are set for:

• Percentage of person miles traveled on the Interstate System that are considered reliable.
• Percentage of person miles traveled on the non-Interstate NHS that are considered reliable.

State DOTs must establish a single index for the Interstate system in the state for five peak hour travel time periods which include peak daytime periods, an overnight period, and weekend periods. The TruckTravel Time Reliability (TTTR) Index is measured by the ratio of the congested peak period travel time (95th percentile) to the normal peak period travel time (50th percentile), on each road segment on the Interstate system for the time periods. The highest TTTR value is used to determine the reliability of the Interstate system for truck traffic or freight reliability. The DOT establishes two- and four-year targets for:

• The ratio of the congested period travel time to the normal period travel time, weighted by the length of the Interstate segment, for the entire Interstate system in the state.

Performance of the CMAQ Program – For Information Only

There are three performance measures established to measure the performance of the federal Congestion Mitigation and Air Quality (CMAQ) program. Two of the measures assess the program’s influence on traffic congestion and the third measures the program’s performance in reducing on-road mobile source emissions. Importantly, Congestion Mitigation and Air Quality measures are not applicable to the State of Rhode Island but are still discussed herein for informational purposes. The CMAQ emissions reduction measure is applicable only to those areas designated as nonattainment or maintenance for ozone, carbon monoxide or particulate matter. The CMAQ traffic congestion measures are applicable only to those nonattainment areas that are also in urbanized areas of over one million people. Rhode Island does not need to comply with these requirements.

State DOTs, in collaboration with the appropriate MPOs, must establish single, unified targets for the Annual Peak Hour Excessive Delay (PHED) and Percent Non-Single Occupant Vehicle (non-SOV) Travel on the NHS in urbanized areas (UZAs) that intersect with Clean Air Act Nonattainment or Maintenance Areas. Single targets are established for an entire UZA across state and MPO boundaries through a collaborative planning process. Peak Hour Excessive Delay (PHED) per capita on the NHS is the threshold for excessive delay and is based on the travel time at 20 miles per hour or 60 percent of the posted speed limit travel time, whichever is greater, and is measured in 15-minute intervals. The measure indicates the traffic delay experienced by travelers throughout an entire year on roadways, specifically during the peak hours. Peak travel hours are defined as 6–10 a.m. on weekday mornings and the weekday afternoon period is 3–7 p.m. The total excessive delay metric is weighted by vehicle volumes and occupancy.

The performance-based planning regulation requires that state DOTs set two- and four-year targets for PHED and percent non-SOV Travel for urbanized areas (UZAs) with populations greater than 1 million people in the first performance period (beginning in 2018) and two- and four-year targets for UZAs with populations greater than 200,000 people in the second and subsequent performance periods (beginning in 2022). Targets are set for:

• Annual hours of peak hour excessive delay per person for the entire UZA.
• Percentage of travel in an UZA conducted by means other than a SOV.

State DOTs whose geographic boundaries include any part of a nonattainment or maintenance area for ozone, carbon monoxide, or particulate matter are required to establish two- and four-year targets for the quantifiable pollutants that are reduced through transportation projects funded through the CMAQ program. State DOTs establish targets for the entire state and the MPO can support state targets or develop MPO targets. Targets for the performance period represent the cumulative pollutant reductions from CMAQ funded projects. Targets are set for:

On-road mobile source emissions reduced through the CMAQ program for the Ozone precursors Nitrogen Oxides (NOx) and Volatile Organic Compounds (VOCs), Fine Particulate Matter (PM2.5), and Carbon Monoxide (CO).

MPOs may either establish quantitative targets for their metropolitan planning area or agree to adopt the statewide targets. As noted, Congestion Mitigation and Air Quality measures are not applicable to the State of Rhode Island but are still discussed herein for informational purposes.

Meeting the Target: The federal NHS travel time reliability rule requires that state DOTs set separate targets for travel time reliability on the entire Interstate system and the non-Interstate NHS system within the state based on the person miles traveled on the percentage of system miles that are deemed reliable for travel time. States meet the targets if the Interstate and non-Interstate NHS system performance is equal to or below the baseline condition or the target established by RIDOT.

If the state does not meet the baseline condition or exceeds its target of travel time reliability on the Interstate system or non-Interstate system (measured separately), the state shall provide documentation identifying why the target wasn’t met and actions that will be taken to improve system reliability.

Meeting the Target: The federal freight system reliability rule requires that state DOTs set a target for truck travel time reliability on the Interstate system based on the ratio of the congested period (95th percentile) travel time to the normal (50th percentile) period travel time on the Interstate system. States meet the targets if the Interstate performance is equal to or below the baseline condition or the target established by the state DOT.

If the state does not meet or exceeds the baseline condition or its targeted ratio of travel times on the Interstate system. The state shall provide additional documentation identifying why the target wasn’t met and actions (in addition to those that are being taken to improve the LOTTR) that are being taken to improve freight system reliability performance.

CMAQ Performance Measures – For Information Only

Meeting the Target: The federal rules requiring the assessment of the CMAQ program’s effectiveness in reducing traffic congestion requires that state DOTs work with MPOs to collaboratively establish two- and four-year targets for PHED on the NHS and percent non-SOV travel in UZAs with populations greater than one million people in the first performance period (2018–2022) and in UZAs with population greater than 200,000 people in subsequent performance periods. DOTs and MPOs are meeting their two and four-year targets if PHED and percent non-SOV travel in the UZA is equal to or below the targets established by the MPOs and state DOTs. If the states and MPOs do not meet these targets, they are able to adjust the targets and evaluate future CMAQ investments that may improve progress towards meeting the targets.

Meeting the Target: The federal rules requiring the assessment of the CMAQ program’s effectiveness in reducing on-road mobile emissions require that state DOTs and MPOs serving UZAs with over one million people establish two- and four-year targets for the amount of applicable emissions that are reduced through CMAQ funded projects for both the MPO region and statewide. Applicable emissions are determined by the attainment status of the criteria pollutants. If the states and MPOs do not meet these targets, they are able to adjust the targets and evaluate future CMAQ investments that may improve progress towards meeting the targets.

The State of Rhode is in compliance with rules and regulations exempting tracking of PHED, % Non-SOV Travel, and Emissions Reductions Targets.