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21st Century Operations Using 21st Century Technologies
Table of Contents

Approaches to Forecasting the Third Performance Management Rulemaking (PM3) Measures for Target Setting

Chapter 1. Introduction

Background

The Moving Ahead for Progress in the 21st Century Act (MAP-21) (Pub. L. 112-141) and the Fixing America’s Surface Transportation (FAST) Act (Pub. L. 114-94) transformed the Federal-aid highway and transit programs by establishing new performance-based planning requirements for State Departments of Transportation (DOT), Metropolitan Planning Organizations (MPO) and providers of public transportation services. Specific requirements for implementing the performance management provisions of MAP-21 and the FAST Act are codified in the Code of Federal Regulations (CFR) at 23 CFR part 490.

The national performance measures—Percent of the person-miles traveled on the Interstate that are Reliable (23 CFR 490.507(a)(1)); Percent of person-miles traveled on the non-Interstate National Highway System (NHS) that are Reliable (23 CFR 490.507(a)(2)); Truck Travel Time Reliability (TTTR) Index Measure (23 CFR 490.607); and Annual Hours of Peak Hour Excessive Delay (PHED) Per Capita Measure (23 CFR 490.707(a))—are collectively referred to as the “travel time-based performance measures” in this document.

Additional information on detailed calculation steps to compute travel time-based and Percent Non-Single Occupancy Vehicle (non-SOV) Travel performance measures can be obtained from FHWA-HIF-18-024 (Federal Highway Administration (FHWA) Computation Procedure for Travel Time-Based and Percent non-SOV Travel Performance Measures).

Introduction

This report provides a step-by-step calculation approach for three forecasting methods in support of target setting for the travel time-based performance measures.

The three forecasting methods covered in this document are:

  • Extrapolation of past trends (macroscopic).
  • Highway segments “at risk” for unreliability (microscopic; based on identifying segments that close to the reliability threshold).
  • Model-based forecasting.

Establishing Targets

The following key items are applicable for State DOTs and MPOs while establishing the targets for the Travel time-based performance measures.

  • Establish two-year and four-year targets for each Performance Period:2
    • Targets for a Performance Period must be reported to FHWA by October 1 of the first year in that Performance Period.3
    • For the first Performance Period, only, 2-year target reporting is NOT required for non-Interstate NHS Travel Time Reliability measure.4
  • Establish a single, unified target (both two-year and four-year) for entire urbanized area for PHED measure:5
    • For the first Performance Period—applicable to State DOTs with NHS in the urbanized area with a population greater than one million containing any part of a nonattainment or maintenance area—two-year target reporting is NOT required for PHED measure.6,7
    • Beginning with the second Performance Period and beyond—applicable to State DOTs with NHS in the urbanized area with a population greater than 200,000 containing any part of a nonattainment or maintenance area.8
  • Adjustment of four-year target allowed at the midpoint of performance period.

Table 1 summarizes the geographic extent, applicable roadways and timeframe for setting the targets for the Travel time-based performance measures.

Metrics and Measures

Performance Measure Rule 3 (PM3) makes a distinction between metrics and measures in its computation guidance. Metrics are intermediate data elements that are computed between the data and the final measures. An example is the Level of Travel Time Reliability which is computed for each of four time periods for individual Traffic Message Channels (TMC) These are then assessed to determine the Percent of the person-miles traveled on the Interstate that are Reliable and the Percent of person-miles traveled on the non-Interstate NHS that are Reliable measures.

Table 1. Summary of required targets under 23 Code of Federal Regulations 490.105.
Performance Measure Geographic Extent Applicable Roadways Timeframe
Percent of person-miles traveled on the Interstate that are reliable Statewide Interstate System 2-year and 4-year targets
Percent of person-miles traveled on the non-Interstate National Highway System that are reliable Statewide Non-Interstate NHS 2-year and 4-year targets
Truck Travel Time Reliability Index Statewide Interstate System 2-year and 4-year targets
Annual Hours of Peak Hour Excessive Delay Per Capita1 Urbanized Areas Entire National Highway System 2-year and 4-year targets

1 State DOTs and applicable MPOs are required to collectively establish and report single targets for Annual Hours of PHED Per Capita and Percent of non-SOV Travel for applicable urbanized areas. [Return to note 1]

2 Defined in 23 CFR 490.101 and 23 CFR 490.105(e)(4) as a 4-year time period during which condition/performance is measured and evaluated to: assess condition/performance with respect to baseline condition/performance; and track progress toward the achievement of the targets that represent the intended condition/performance level at the midpoint and at the end of that time period. For example, the first Performance Period for the Travel time-based performance measures begins on January 1, 2018 and extends for a duration of 4 calendar years. Similarly, the second Performance Period starts on January 1, 2022 and ends on December 31, 2025. [Return to note 2]

3 23 CFR 490.107(b)(1). [Return to note 3]

4 23 CFR 490.105(e)(7). [Return to note 4]

5 23 CFR 490.105(e)(8)(iii) & (f)(5)(iii). [Return to note 5]

6 23 CFR 490.105(e)(8)(i) & (f)(5)(i). [Return to note 6]

7 23 CFR 490.105(e)(8)(vi) & (f)(5)(vi). [Return to note 7]

8 23 CFR 490.105(e)(8)(ii) & (f)(5)(ii). [Return to note 8]

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