Environmental Engineering Reference
In-Depth Information
Table 4 Summary of key data gaps
Freight generation data
No sources were identified a, b
Production
Consumption
Delivery tours
Sequence
Only Global Positioning System (GPS) data
private vendors.
Location
Low level of detail about location.
OD flows
Some source but no complete information.
Empty flows
No source identified.
Economic characteristics
of participating agents
Shippers
Some source can provide some data.
Carriers
Receivers
Spatial distribution/
Location of
participating agents
Shippers
Some source identified that can provide some
data
Carriers
Receivers
Network characteristics
Travel time and
costs
Only a low level of detail is provided by the
identified data sources
Use restriction
capacity
Traffic volumes
Special choice processes
Mode choice
Only the Commodity Flow Survey (CFS) provide
some data
b
Delivery time
Low level of detail
Mode attributes
Some level of detail
Other economic data
Production
functions
No sources were identified
Demand
functions
No sources were identified
Good level of detail from Regional Economic
Information System(REIS) and 2002
Benchmark Input-Output Accounts of the
USA
Notes a ITE Trip Generation Manual contain trip rates but no cargo attracted or produced
information
b The Commodity Flow Survey microdata could provide this information. Access to the data is
restricted
Input-Output
technical
coefficients
estimation of freight Origin-Destination (OD) matrices could be reasonably
achieved using secondary sources such as traffic counts (Tamin and Willumsen
1988 ; Gedeon et al. 1993 ; Tavasszy et al. 1994 ; Nozick et al. 1996 ; List et al.
2002 ; Rios et al. 2002 ; Al-Battaineh and Kaysi 2005 ; Holguín-Veras and Patil
2007 ; Holguín-Veras and Patil 2008 ). In fact, the truck OD matrix in the New
York City Metropolitan Planning Organization transportation planning model is
the result of such process (List et al. 2002 ). As a result, there is a wide range of
data collection possibilities that differ in the extent of the synthesis that is con-
ducted. At one end of the spectrum, a modeler could undertake freight demand
modeling with a minimal amount of data, which requires the use of a significant
number of assumptions and demand synthesis techniques. In this context, synthesis
techniques could indeed reduce data collection costs, though at the expense of
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