交通运输工程导论
中国航海日-党员发言
transportation engineering
[交通工程]：the application of scientific principles to
the
planning, design, operation, and
management of transportation systems.
transportation planning [交通计划]：an act of
laying out a transportation system aiming to
predict the needsdemands for a particular
service.
ITS( intelligent transportation
systems )[智能交通系统]：a system providing the
opportunity to integrate travelers, vehicles
and infrastructure into a comprehensive system
through a range of technologies.
Transportation is everything involved in
moving either the person or goods from the origin
to the destination.
The first pipelines in
the United States were introduced in 1861.
First railroad opened in 1825.
The internal-
combustion engine was invented in 1866
The
first automobile was produced in 1886
The
Wright brothers flew the first heavier-than-air
machine in 1903
The first diesel electric
locomotive was introduced in 1921
Lindbergh
flew over the Atlantic Ocean to Europe in 1927
The first diesel engine buses were used in
1938
The first limited-access highway in the
United States (the Pennsylvania Turn-pike) opened
in
1940
The Interstate Highway system was
initiated in 1950
The first commercial jet
appeared in 1958
Astronauts landed on the
moon in 1969
Because of the multidisciplinary
content of transportation engineering , training
transportation
engineers and planners use the
following fields of knowledge :
economics
geography
operations research
regional planning
sociology psychology
probability
statistics
看Physical facilities, including
streets, roads, and highways; railroads, airports,
sea and river
ports pipelines, and canals
Fleets of vehicles, vessels, and aircraft
Operating bases and facilities, including
vehicle maintenance facilities and office space
Organizations
Operating strategies,
including vehicle routing scheduling, and traffic
control
看Elements of Transportation systems:
Links
Vehicles
Terminals
Management and labor
As for the
transportation system, the elementary demands are
:
Accessibility (ubiquity)
Mobility
Efficiency
Serviceability.
The following are brief
descriptions of the more important modes in the
United States
transportation system,
including:
Highways Urban
Transit
Air Rail
Water Pipelines
According to the engine and the driving or
pulling forces:
steam engine
internal-combustion engine
electric
engine
A container is a large reusable
receptacle that can accommodate smaller cartons or
cases in a
single shipment, designed for
efficient handling of cargo
看Advantages:
Standard transport product
Flexibility of
usage
Management
Costs
Speed
Warehousing
Security
Drawbacks :
consumption of space
infrastructure
costs
stacking
management logistics
empty travel
illicit trade
Definition
Public transportation
is an important element of the total
transportation services provided
within large
and small metropolitan areas.
Up to six
distinct travel movements may be present in a
typical trip:
Main movement
Transition
Distribution
Collection
Access
Termination
A freeway is a divided highway facility having two
or more lanes in each direction for
the
exclusive use of traffic, with full control of
access and egress.
There are four
major classes of highways that may be identified:
Limited-access facilities
Arterials
Collectors
Local streets
Uninterrupted flow
Facilities have no
external interruptions to the traffic stream
Interrupted flow
Facilities
incorporate fixed external interruptions into
their design and operation.
The major
difference between uninterrupted and interrupted
flow facilities is the impact of
time.
On uninterrupted facilities, the physical facility
is available to drivers and vehicles at all
times.
On a given interrupted flow
facility, movement is periodically barred by “red”
signals.
Therefore, interrupted flow is,
more complex than uninterrupted flow.
An
intersection is an area shared by two or more an
area of decision for all drivers;
each must
select one of the available choices to proceed.
Its main function is to allow the change of
route directions.
An intersection needs to
be designed with great care, taking into
consideration efficiency,
safety, speed, cost
of operation, and capacity.
traffic
flow [交通流]: be done with the aim to get a better
understanding of these phenomena
and to assist
in prevention of traffic congestion problems.
Smooth
the one where the
conveyance has an even or gentle motion or
movement in a good order,
also called
uninterrupted flow
Stiff
Uninterrupted flow occurs when vehicles traversing
a length of roadway are not required to
stop
by any cause external to the traffic stream, such
as traffic control devices.
Interrupted flow
occurs when flow is periodically interrupted by
external means, primarily
traffic control
devices such as stop and yield signs and traffic
signals.
Uninterrupted flow
Freeways
Multilane highways
Two-lane highways
Interrupted Flow
Signalized streets
Unsignalized streets with stop signs
Arterials
Transits
Pedestrian walkways
Bicycle
paths
The major difference between
uninterrupted and interrupted flow facilities is
the impact
of time.
On uninterrupted
facilities, the physical facility is available to
drivers and vehicles at all
times.
Interrupted flow is, therefore, more complex
than uninterrupted flow
Primary variables:
They are three macroscopic parameters used to
describe traffic stream.
speed (v)
volume
(q )
density (k)
Density
It is the
measure most directly related to traffic demand.
It measures the quality of traffic flow,
as it measures the proximity of other
vehicles, a factor which influences freedom to
maneuver
and the psychological comfort of
drivers.
When the density on the highway is
zero, the flow is also zero.
As the density
increases, the flow also increases.
when the
density reaches its maximum, the flow must be
zero.
It follows that as density increases
from zero, the flow will also initially increase
from zero to
a maximum value.
最小树问题求解方法：
T(V,)
；建立空边集图
While（T中所含边数小于n－1）
{ 从E中选取当前最短边（u，v）；
从E中删除边（u，v）；
if（（u，v）并入T中，并不产生回路，将（u，v）并入T中；
}FLOYD法求解最短路问题的
C语言参考程序：
FLOYD(A,C)
Float A[][n], C[][n];
{
for(i=0;i
{
if(C[i][j]!=max) path[i][j]=j;
else path[i][j]=0;
A[i][j]=C[i][j];
}
for(k=0;k<=n;k++)
for(i=0;i
{
if(A[i][j]>A[i][k]+A[k][j]) {
A[i][j]>A[i][k]+A[k][j];
path[i][j]=path[i][k];
}
}