Anne Goodchild | Andrea Gagliano | Maura Rowell October 10, 2013 Examining Carrier Transportation Characteristics along the Supply Chain
Regional Travel Modeling of Freight Takes economic and landuse data as input Often uses 4-step model – Gravity model for truck trip distribution – There is no truck mode choice model as all travel is assumed to occur via the truck mode. – Estimates truck demand based on employment or square footage – Often includes different truck sizes and times of day Serves as input to benefit/cost and emissions model
Purpose of the Study Examine carriers and characterize statistically significant, predictable transportation patterns at the regional and statewide level. Recommend ways to incorporate supply chain characteristics into regional models used by regional and statewide transportation planning organizations. The goal is not to capture all of the complexity of supply chain logistics but to identify discriminating categories from a transportation perspective.
Survey Design minute phone interview to illicit transportation characteristics: – Fleet statistics – Carrier services – Travel distances – Time of day travel patterns – Company characteristics – Routing logic Questions were all asked at the strategic and aggregate level, rather than in reference to specific shipments. 522 responses from private and for-hire carriers
Key Question Does your company own/operate facilities which require private transportation? o raw production facility o manufacturing plant o storage center o distribution center o retail store If the respondent answered yes to any node carrier If the respondent answered no to all link carrier
Analysis Methods Continuous data: Welsh two sample t-test Categorical data: Fisher comparison of proportions test Significant transportation characteristics: – delivery/pickup type – frequency – location – style – time of day – time windows
Weighting for Vehicles CategoryNumber of Carriers Number of Vehicles Link42215,664 Node1161,882 Raw/manufacturing42419 Storage/distribution32600 Retail1270 Multi-node29793
Node carriers make fewer deliveries Proportion that responded “yes”
Link carriers visit fewer residences Proportion that responded “yes”
Link carriers most often visit distribution centers Proportion that responded “yes”
Link carriers operate early Proportion that responded “yes”
Link carriers have tighter time windows Proportion that answered “yes”
Link carriers have less scheduled deliveries Proportion that answered “yes”
Carrier Classification Type of CarrierClassification Criteria LinkNone Node Raw/ManufacturingRawManufacturing Raw and Manufacturing Storage/DistributionStorageDistribution Storage and Distribution Retail Multi-LinkAll other combinations
Recommendations Classifies carriers as node and link carriers Capture the differences in transportation characteristics between carrier types: – delivery/pickup type, – frequency, – location, – style, – time of day, – and time windows.