Chapter 2 Performance Measures

Transcription

1 Transportation Decision-making Principles of Project Evaluation and Programming Chapter 2 Performance Measures K. C. Sinha and S. Labi Purdue University School of Civil Engineering 1

2 Performance Measures in Transportation Evaluation Introduction Goals, Objectives and Measures Network and Project Levels Objectives Linking Goals to Measures 2

3 What is Performance? Execution of a required function Performance measures represent the extent to which a specific function is executed Whose point of view? User Agency Operator Other stakeholders 3

4 Measures are needed at various levels System-wide plans and programs Solutions for a specific localized problem ISTEA of 1991 GASB resolution of

5 Overall Goals Goals Objectives Performance Measures Performance Criteria Performance Standards 5

6 Contd. Overall Goal: Efficiency, Effectiveness, Equity Goal: Under effectiveness, goals can cover condition (system preservation), operational characteristics, (safety, mobility) or external effects (environmental conservation) Objective: If goal is to enhance regional air transportation mobility, objective can be to reduce air travel time 6

7 Contd. Performance Measure: Performance indicator, e.g. air traveler delay Performance Criterion: A specific definition attached to a measure, e.g. to minimize average transfer time Performance Standard: A fixed value of a criterion threshold, trigger value, minimum level of service, e.g. average transfer time cannot exceed 90 minutes 7

8 Typical Goals, Objectives, Performance Measures and Performance Criteria for Efficiency 8

9 Typical Goals, Objectives, Performance Measures and Performance Criteria for Equity 9

10 Performance Measures at Network and Project Levels Network Level: System-wide evaluation of program, policies, funding, investment strategies. Project Level: An optimum policy, design or preservation strategy for a specific facility (pavement section, bridge, transit terminal, etc.) at a given time or over life cycle. 10

11 Example: Air Transportation 1. Network Level: Change in average plane delay across a region or airline network in response to national airport security measures. 2. Project Level: Change in average plane delay at a given airport because of a runway expansion project. Optimal decisions at project level may not mean optimal decisions at network level and vice versa. 11

12 Properties of a Good Performance Measure Appropriateness adequate representation of goals and objectives. Measurability can be accurately measured. Dimensionality should be able to capture the required level of each evaluation dimension. e.g. appropriate spatial/temporal scales. Realistic data collection at a reasonable cost. Defensible clear and simple in definition and method of computation. Forecastable can be determined reliably in the future. The set should be comprehensive, but manageable. 12

13 Dimensions of Performance Measures Dimension Overall Goals Objectives Sector Concerns Flow Entity Modal Scope Specific Mode Affected Entity and Stakeholder Spatial Scope Level of Agency Responsibility Time Frame Level of Refinement Intended Use Level of Use of Information Example Economic Efficiency, Effectiveness, and Equity Preservation of System Condition, Operational Efficiency, Economic Development, Quality of life, Safety, and Environment Private (Profit), Public (Service) Freight and Passenger Multi-modal and Single mode Highway, Urban Transit, Railway, Waterway and Pipeline Inter-modal Agency, User or Non-User Urban, Rural, City-wide versus Intercity State, District, Local Long-term and Short-term Primary and Secondary Indicators Policy, Programming, Implementation, Post-implementation Review Management and Operational Levels 13

14 Operational Performance Accessibility The ability to handle specific types of passenger or freight The capacity of specific inter-modal facilities The ease of access to the system The ease of connecting at transfer facilities The percentage of population or freight generating business within a certain time/distance 14

15 Mobility Travel time, LOS, speed, delay, congestion Average speed vs. peak period speed Transfer time at inter-modal facilities, hours of delay Percentage of a facility not heavily congested during peak period. 15

16 Operational Efficiency Cost per unit of facility dimension (initial cost maintenance, preservation) Total life cycle cost User cost per unit use Total life cycle user costs and benefits 16

17 Safety Frequencies or rates (per mile, per AADT, per VMT) Severity types (fatal, injury or PD) 17

18 Reduction in Vulnerability as a Measure of Performance 18

19 Security from Extreme Events Vulnerability Rating Likelihood Consequence 19

20 Economic Development and Land Use Number of businesses Business sales Number of jobs Per capita income Average and proportions of commercial, residential and agricultural land areas 20

21 Environmental Quality and Resource Conservation Average of wetlands affected Pollutant emissions and concentrations Noise and vibration levels Energy consumption 21

22 Quality of Life Overall well-being Community spirit Social equity Privacy Aesthetics Concern for the disadvantaged 22

23 Sector Concerns and Interests Private Sector Public Sector Toll Roads Operator Transportation Provider Shipper Trucker Etc. Federal, State and Local Government Agencies Profit Service 23

24 Flow Entity Passenger Delay/passenger Out-of-pocket costs Travel time reliability Freight Boarding time Inventory time and cost Travel time reliability 24

25 Examples of Network-level Performance Measures Based on Highway System Goals and Objectives 25

26 Contd. 26

27 Summary of Transit Performance Measures 27

28 Airport Facilities Operational Adequacy Gate delay Physical Adequacy Runway/Taxiway Airspace use restrictions Environmental and Land Use Compatibility Height zoning Airport in local planning Noise management 28

29 Continued Financial Performance Operating ratio Level of subsidy Revenue passenger served Accessibility Ground and air access 29

30 Inter-modal Facilities P.C. time congestion experienced Incident frequency or severity Average travel time for passengers or freight mode Inter-modal transfer time reliability 30

31 Entity or Stakeholder Affected Agency Adjacent businesses / residents Environmental group Spatial Scope Statewide, Countrywide, Citywide, etc. Corridor or specific segment or mode Level of Agency Responsibility State / Local Time Frame and Level of Refinement Primary Secondary 31

32 Benefits of Using Performance Measures Clarity and transparency of decisions Attainment of policy goals Internal and external agency communications Monitoring and improvement of agency business processes 32