Path marginal cost （PMC） is the change in totaltravel cost for flow on the network that arises when timedependentpath flow changes by 1 unit. Because it is hardto obtain the marginal cost on all the links, the local...Path marginal cost （PMC） is the change in totaltravel cost for flow on the network that arises when timedependentpath flow changes by 1 unit. Because it is hardto obtain the marginal cost on all the links, the local PMC,considering marginal cost of partial links, is normallycalculated to approximate the global PMC. When analyzingthe marginal cost at a congested diverge intersection, ajump-point phenomenon may occur. It manifests as alikelihood that a vehicle may unsteadily lift up （down） inthe cumulative flow curve of the downstream links. Previously,the jump-point caused delay was ignored whencalculating the local PMC. This article proposes an analyticalmethod to solve this delay which can contribute toobtaining a more accurate local PMC. Next to that, we usea simple case to calculate the previously local PMC and themodified one. The test shows a large gap between them,which means that this delay should not be omitted in thelocal PMC calculation.展开更多
A methodology is proposed to evaluate and rank potential sites for facilities dealing with hazardous materials(HAZMAT).The proposed methodology incorporates HAZMAT route planning into facility siting while considering...A methodology is proposed to evaluate and rank potential sites for facilities dealing with hazardous materials(HAZMAT).The proposed methodology incorporates HAZMAT route planning into facility siting while considering transportation preferences and challenges.The area of interest is divided into smaller zones representing potential sites for a HAZMAT facility.A multimodal transportation network including railways and roads is considered for transportation of HAZMAT.Each zone is evaluated based on its accessibility from a set of selected points of interests(POIs),which are defined as potential origin/destination points for transportation of HAZMAT.The shortest routes between each POI and potential zones are evaluated based on a cost function which can accommodate multiple criteria to determine the associated disutility for each potential zone.Finally,zones are ranked based on their cumulative disutility scores.The proposed analysis method is quantitative,and at the same time it is adequately flexible to allow inclusion of subjective criteria.Application of the proposed methodology is demonstrated for identifying optimal locations for a HAZMAT facility(e.g.,a nuclear facility)using the Canadian province of Saskatchewan as an example.Three scenarios were evaluated including(1)all network segments and POIs were treated equally,(2)network segments were rank ordered based on their functional classification while POIs were treated equally and(3)network segments were rank ordered based on their functional classification with preferences given to specific POI(s).展开更多
文摘Path marginal cost （PMC） is the change in totaltravel cost for flow on the network that arises when timedependentpath flow changes by 1 unit. Because it is hardto obtain the marginal cost on all the links, the local PMC,considering marginal cost of partial links, is normallycalculated to approximate the global PMC. When analyzingthe marginal cost at a congested diverge intersection, ajump-point phenomenon may occur. It manifests as alikelihood that a vehicle may unsteadily lift up （down） inthe cumulative flow curve of the downstream links. Previously,the jump-point caused delay was ignored whencalculating the local PMC. This article proposes an analyticalmethod to solve this delay which can contribute toobtaining a more accurate local PMC. Next to that, we usea simple case to calculate the previously local PMC and themodified one. The test shows a large gap between them,which means that this delay should not be omitted in thelocal PMC calculation.
基金supported by Sylvia Fedoruk Canadian Centre for Nuclear Innovation
文摘A methodology is proposed to evaluate and rank potential sites for facilities dealing with hazardous materials(HAZMAT).The proposed methodology incorporates HAZMAT route planning into facility siting while considering transportation preferences and challenges.The area of interest is divided into smaller zones representing potential sites for a HAZMAT facility.A multimodal transportation network including railways and roads is considered for transportation of HAZMAT.Each zone is evaluated based on its accessibility from a set of selected points of interests(POIs),which are defined as potential origin/destination points for transportation of HAZMAT.The shortest routes between each POI and potential zones are evaluated based on a cost function which can accommodate multiple criteria to determine the associated disutility for each potential zone.Finally,zones are ranked based on their cumulative disutility scores.The proposed analysis method is quantitative,and at the same time it is adequately flexible to allow inclusion of subjective criteria.Application of the proposed methodology is demonstrated for identifying optimal locations for a HAZMAT facility(e.g.,a nuclear facility)using the Canadian province of Saskatchewan as an example.Three scenarios were evaluated including(1)all network segments and POIs were treated equally,(2)network segments were rank ordered based on their functional classification while POIs were treated equally and(3)network segments were rank ordered based on their functional classification with preferences given to specific POI(s).
