| Summary: | 碩士 === 淡江大學 === 土木工程學系 === 84 === The study investigates the optimal modal combination in
metropolitan by supply-oriented approach. The "supply-oriented"
means an optimal modal combination with minimum system total
cost under the consideration of environment loads including the
limitations from transportation modes capacity,road capacity,
parking capacity and environmental pollution. This study uses
the mathematical programming to formulate and develop an optimal
modal combination model. The objective function is the sum of
user cost,operator cost and accident cost;the contraints cover
the limitations from transportation modes capacity,road
capacity,parking capacity,environmental pollution and travel
demand. The right-hand-side for the constraints are obtained
based on the environment loads in the metropolitan area which is
assumed to be ultimate as observed. In addition, some factors
such as "congestion rate" and "V/C ratio" are also considered in
the model as a performance index for defining the level of
service. Taipei Metropolitan Area is used as a case for
analysis, the result shows that under the traffic pattern during
peak hour, with "MRT" scheme, the demand sharing proportion of
the optimal modal combination for mass (MRT,bus,taxi) and
private(automobile,motorcycle) transportation are 69% and 31%
respectively; under the same traffic pattern, without "MRT"
scheme,the demand sharing proportion of the optimal modal
combination for mass and private transportation are 52% and 48%
respectively. Under the daily traffic pattern, with "MRT"
scheme, the demand sharing proportion are 57% and 43%
respectively ;the same traffic pattern,without "MRT" scheme,the
demand sharing proportion are 45% and 55% respectively.
Sensitivity analysis shows the mass transportytion when the
parameters such as occupancy,frequency,operating rate increase,
he volume sharing proportion will increase accordingly. The main
reason for that is the cost for using mass transportation mode
is lower than using private transportation mode. The scenario
analysis are shown as following:1.Implementation of carpool
strategy:when the occupancy reaches 3-person,the cost for using
the automobiles is lower than using the taxis,the optimal modal
combination is changed and the objective value is decreased
approximately20%,from NT$123,970,000 to NT$99,460,000 per hour.
2.Implementation of taxipool strategy:when the occupancy resches
4-pers on,the cost for using taxi is lower than motorcycle,then
the optimal modal combination is changed and the objective value
is decreased approximately 4%, from NT$123,970,000 to
NT$119,310,000 per hour. 3.Implementation of free bus
strategy:when the strategy is implemented, the out-of-pocket
cost is 0,then there is no influence on the optimal modal
combination. 4.Taxi license regulation issue:the optimal
proportion of taxi is about 13% equivalent to 490,000 person
trips,currently it only shares demand of 7% equivalent to
258,000 person trips.It appears the releasing taxi liense
regulation or implementation of "peak-hour-fare" are
necessary.5.Parking issue:parking facility is seriously
insufficient in Taipei. It appears that increasing the supply of
off-street parking facility is necessary.
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