A Supply-Oriented Study on the Optimal Modal Combination in Metropolitan Area

• Main Authors: Lin, Ming-Der, 林明德
• Other Authors: Lau,Shiao-Shien
• Format: Others
• Language: zh-TW
• Published: 1996
• Online Access: http://ndltd.ncl.edu.tw/handle/08170858596947669587

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.