SM
Metropolitan Transportation Information
System
Progress Update
2008 October
Instrumentation/Analysis
• Empty Containers
• Stack Management • Data
Support • Commercialization
The mission of the MeTrIS project is to develop
geospatial tracking and modeling technologies to smooth the flow of
freight through the San Pedro ports and the Los Angeles basin. Our work
does not end with GPS tracking; it begins with GPS tracking.
The project is funded by the USDOT and cost share
from the investigative team and partners.
Instrumentation and
Analysis
We have been following
a small fleet of drayage
trucks serving the San Pedro ports. The first truck was instrumented
with an
onboard data logger in August 2007. In November 2007 we began testing
custom-manufactured real-time reporting units. We have acquired 100
units and are in the process of installing them. We will ramp up to 500
trackers in the coming months.
Our units sample truck locations at
intervals of about 12 seconds, creating detailed traces of
routes, stops, speeds, etc (by comparison, commercial tracking is
typically at 5-15 minute intervals). To date we have more than
130
truck months of data and have developed preliminary analytical tools.
Several original
GPS-enabled information products have been created, including:
- Terminal turn times, measured not only from the
moment of admission at the terminal gates, but also from when trucks
join the queue outside a terminal
- Traffic "drainage:" proportion of drayage
traffic exiting along a freeway or thoroughfare
- Speed on freeways and other port access routes,
and speed variability, by time of day
- Detour behavior when traditional routes are
closed or congested
- Use of non-truck-designated streets
A web page of sample
outputs is publicly
accessible.
Lead: Digital Geographic Research
Corporation
Model: Empty Container
Management
Deadhead trips
(bobtails, bare chassis and empty
container hauls) account for roughly half the traffic on port access
routes such as I-710. Our Optimal Storage of Empties Model (OSEM),
developed by Dr Richard Church and Ting Lei at UC Santa Barbara, shows
that 25% of deadhead trips can be eliminated, by establishing
strategically placed depots
for empty containers. There are practical barriers that may limit this
degree of benefit, including container branding, per diem charges, and
motor carriers' revenue models. The magnitude of common potential
benefit, in efficiency as well as air quality, may
help to overcome these policy barriers.
Model variants consider various possible
management practices, such as hauling containers to the nearest depot
(trucker-optimal) with a separate activity to balance depot inventory,
versus a system-optimal strategy that would involve an authority that
directs trucks to designated depots and dynamically advises consignees
and shippers of potential street turns. Future work will develop
decision support models
to permit multiple stakeholders to examine the individual and
system-wide costs and benefits of each strategy, and depot location
scenarios.
Lead: University of
California,
Santa Barbara
Model: Container Stack
Management
Much of the delay at
port and rail terminals
arises when containers have to be retrieved from grounded stacks.
Murphy's Law holds that the container requested is invariably at the
bottom of the stack, requiring upper boxes to be repositioned. This
rehandling forms a large proportion of crane moves, the exact
numbers depending on stack height.
With knowledge of estimated time of arrival (ETA)
of trucks, our container stack management models, developed by Dr Anne
Goodchild and Wenjuan Zhou at the University of Washington, show that
rehandles
can be reduced by 25-50%, with considerable ramifications for
reducing truck wait/idle time, and improving terminal velocity and air
quality. Generally speaking, containers expected to be picked up soon
are positioned near the top of the stack. Again, there are barriers,
from labor implications to truck queue management. And again, the
variety and magnitude of benefits will be a powerful argument towards
overcoming the barriers.
Lead: University of
Washington
Data Support
Dr Mike Goodchild and Linna Li at UC Santa Barbara
have developed a data model for geospatial
representation of port drayage. A data model specifies the data
elements of essential entities (e.g. ports, terminals, trucks,
containers, chassis, warehouses), their essential attribute fields and
their relationships to one another, facilitating data handling and
exchange. The ESRI UNETRANS
model, a generic template for transportation data, was developed 6-8
years ago by the UC Santa Barbara research team. The drayage data model
is a vertical
UNETRANS-compatible component.
Our conflation
solution matches one street
database to another,
blending the positional advantages of one with the attribute accuracy
of the other.
There is always positional uncertainty in
geospatial
data. The locations of roads and other facilities (like most other
data, e.g. population, corporate earnings) are specified with some
degree of uncertainty, that is tolerable for some applications but
perhaps
not for others. Road maps are typically up to 5 meters (1½
lanes)
off their true
locations in major cities. When marrying GPS data with infrastructure
maps, for example, these errors propagate and cause analytical and
modeling problems.
Conflation is related to map matching, the problem
of determining the street that a GPS position is on. Due to errors in
GPS as well as the map base, map matching can return a position on the
wrong block the wrong highway, or the service road rather than the
highway. Resolving these errors is essential to our work, and of
universal utility
to geospatial analysis.
Lead: University of California,
Santa
Barbara
Outreach and
Commercialization
All of the above efforts are being developed with
the eventual objective of
commercial deployment. With our partners, Bill Lyte of CALMITSAC and
John
Glanville at Athenaeum Capital Partners, we are actively publicizing
our
research results
and developing paths towards commercialization in conjunction with
other goods movement technologies and local development initiatives. We
welcome opportunities to broaden the circle
of
partners
researching, developing and supporting MeTrIS.
Leads: Digital
Geographic Research
Corporation with Athenaeum Capital Partners,
CALMITSAC
MeTrIS home
• MeTrIS information
products • UCSB
project web site
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