Anne Goodchild | Andrea Gagliano | Maura RowellOctober 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• 15-20 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 facilityo manufacturing planto storage centero distribution centero 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

Category Number of Carriers

Number of Vehicles

Link 422 15,664Node 116 1,882Raw/manufacturing 42 419Storage/distribution 32 600Retail 12 70Multi-node 29 793

Node carriers make fewer deliveriesPr

opor

tion

that

resp

onde

d “y

es”

Multiple Times a Day

Daily Weekly Monthly Less than Monthly

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

90.0

100.0

Link

Node

Raw/Manufacturing

Storage/Distribution Center

Retail

Multi-Node

Link carriers visit fewer residences

Link node 0

102030405060708090

100

ResidentialBusiness

Prop

ortio

n th

at re

spon

ded

“yes

”

Link carriers most often visit distribution centers

Manufacturing Facility

Distribution Center

Intermodal Facility

0102030405060708090

100

Link Node

Prop

ortio

n th

at re

spon

ded

“yes

”

Link carriers operate early

Morning Daytime Evening Overnight0

10

20

30

40

50

60

Link Node

Prop

ortio

n th

at re

spon

ded

“yes

”

Link carriers have tighter time windows

Less than 30 Min 1 to 2 Hours Half Day All Day0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

90.0

100.0

Link Node Raw/Manufacturing Storage/Distribution CenterRetail Multi-Node

Prop

ortio

n th

at a

nsw

ered

“ye

s”

Link carriers have less scheduled deliveries

Link

Node

Raw/M

anufactu

ring

Storag

e/Dist

ribution

Retail

Multi-Node

0

10

20

30

40

50

60

70

80

FCFSScheduled

Prop

ortio

n th

at a

nsw

ered

“ye

s”

Carrier Classification

Type of Carrier Classification Criteria

Link None

Node

Raw/Manufacturing Raw Manufacturing Raw and Manufacturing

Storage/Distribution Storage Distribution Storage and Distribution

Retail Retail

Multi-Link All 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.

annegood@uw.edu