A STATED PREFERENCE APPROACH TO EXAMINING THE VALUE OF TRAVEL TIME AND RELIABILITY FOR FREIGHT TRANSPORTATION

Transcription

1 A STATED PREFERENCE APPROACH TO EXAMINING THE VALUE OF TRAVEL TIME AND RELIABILITY FOR FREIGHT TRANSPORTATION FSERPM UG Meeting September 18th, 2015 Xia Jin LCTR, FIU

2 Outline Background Purpose Objectives Challenges Stated Preference Survey Recruitment Experiment Design

3 Background Growing demand for freight transportation Better understanding of freight behavior Increasing role of reliability in freight transportation

4 Purpose Value of Reliability (VOR) refers to the monetary value users place on reliability, or how much the users are willing to pay to reduce the variability of travel time. It is a critical parameter in benefit-cost analysis, and transportation planning to measure the monetary equivalency of improvements in reliability. This study aims to understand how the freight community value travel time reliability in their transportation decisions.

5 Benefits to the Community Support investment decisions that reflect the needs of freight stakeholders better understanding of how the users (shippers and carriers) respond to changes in reliability tools to evaluate alternative freight management and operational strategies.

6 Project Objectives Review existing studies on VOR and identify knowledge and data gap; Conduct stated preference survey to understand user decision-making; Develop models to estimate VOR by stratification, such as, commodity type, trip length, and business type, etc. Incorporate VOR in freight analysis and project evaluation.

7 Challenges Insufficient knowledge in freight transportation and supply chain management, and lack of mechanism to incorporate the knowledge into the freight planning process; Lack of data in supporting research and modeling efforts as freight movement data tend to be proprietary in nature, aggregate in geographic scale, and difficult to collect from private sectors; and Lack of guidance in freight sector survey design in constructing realistic alternative scenarios and questionnaire for the respondents.

8 Stated Preference (SP) Survey SP surveys are designed to collect preference information from the users through hypothetical scenarios. Recruitment Stage Background information One recent shipment information SP Scenarios Eight to nine scenarios, each consists of 2 or 3 alternatives

9 Survey Method Survey Sample Design Internet Computer assisted Telephone Interview (CATI) Market segmentation Sample size Survey Approach Pilot Survey Questionnaire Design Identification of alternatives, attributes & attributes level Experimental design Generate choice sets Survey Implementation Retrieval Recruitment Recruitment of respondents Collection of background information for screening purpose Sample enough? No Yes Yes Revision required? Data processing & Monitoring No Main Survey Model Estimation Preliminary VOR Estimates Model Verification Final VOR Estimates

10 Proposed Market Segment - Shippers Shippers Delivery Window Pressure Truck Light Medium Heavy Rail Water ways Air Perishable No X X X X X X Yes X X X X X X Nonperishable No X X X X X X Yes X X X X X X

11 Proposed Market Segment - Carriers Carriers Shipping Distance Truck Light Medium Heavy Rail Shipping Distance Water -ways Air Containerized 300+ X X X 300- Miles 1000 <50 Miles X X X Miles Non- Containerized <50 Miles X X X Miles X X X <300 Miles Miles 300+ Miles X X X X X X > 1000 Miles X X X X X

12 Experimental Design Type C1 within-mode trade-offs among travel time, cost and reliability; C2 within-mode trade-offs among travel time, cost, reliability, and departure time; C3 cross-mode trade-offs between roadway and railway shipment based on travel time, cost, travel time reliability, service flexibility and probability of shipment damage. C4 cross-mode trade-offs between roadway and railway based on travel time, cost, travel time reliability, departure time, service flexibility and probability of shipment damage.

13 Design Flow

14 Recruitment Instrument Shipment Information

15 Recruitment Instrument Background Information

16 Experiment Design Type Alternative Type No. of Attributes Attributes (Level) Experiment Design No of choice sets Road Rail Air Water ways C1 Within Mode 3 C2 C3 C4 Within Mode Between Modes (Road & Rail) 4 5 Between Modes (Road & Rail) 6 Travel time (5), Cost (5), Reliability (5) Travel time (5), Cost (5), Reliability (5), Departure time (2) Travel time (5), Cost (5), Reliability (5), Service Flexibility (2), Probability of Property Damage (2) Travel time (5), Cost (5), Reliability (5), Service Flexibility (2), Probability of Property Damage (2), Departure time (2) Fractional Factorial 25 Fractional Factorial 25 Manual (Bradley) 44 Fractional Factorial 30 * Reliability is defined as the standard deviation of travel time

17 Experiment Design C1

18 C2

19 C3

20 C4