Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter.
Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.
Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.
OCR for page 16
CHAPTER 3
Drayage Data and
Information Sources
Data and Information Needs
Drayage data are required for the following three basic purposes:
· To measure and analyze drayage bottlenecks and delays,
· To evaluate potential solutions and best practices, and
· To calibrate DrayFLEET or other cost and emissions models.
Bottlenecks extend the overall cycle time (e.g., terminal to customer and return) beyond what is
necessary to accomplish the actual work of transporting the container. Bottlenecks will thus be
manifest as larger-than-necessary cycle times. Identifying and measuring bottlenecks will require
data on the overall cycle time, its components, and--especially--those components that contain
potential bottlenecks.
"Before-and-after" time series data or "with-and-without" cross-section data are needed to eval-
uate potential solutions and best practices. Terminal operators often make process or facility
improvements to avert the development of significant problems rather than waiting for the prob-
lems to develop. The "improvement," therefore, is sometimes only evident in comparing the pres-
ent performance with a hypothetically worse performance.
Although discussions with drayage firms and terminal operators can suggest likely bottlenecks
and sources of delay, more intensive data mining is usually necessary to verify, quantify, analyze,
and prioritize the issues.
DrayFLEET and other emissions or cost models require data on port characteristics, cargo flows,
distances, cost factors, etc.
Depending on the issue to be analyzed, data may be needed on the whole drayage cycle,
as follows:
1. Travel times to marine terminals,
2. Inbound gate queue times,
3. Inbound gate processing times,
4. Container yard transaction times,
5. Outbound gate queue times,
6. Outbound gate processing times,
7. Travel times to customers (or depots or rail terminals), and
8. Transaction times at customer locations (or depots or rail terminals).
Each of these eight generic time segments may need to be investigated in depth and broken
down into such levels of detail as are appropriate, supportable, and informative. There are sev-
eral potential sources for these data as follows:
16
