Optimal Link Tolls for Multi-node and Multi-link Transportation Networks Taking into Account the Welfare Cost of Fund Procurement

This study discusses the optimal link toll,which maximizes social surplus under a user equilibrium condition,with imperfect substitution assumption for route choice in a transportation network with many nodes and links,as well as taking into account the welfare cost of funds procurement.In contrast to previous studies,this study formulates optimal link tolls,taking into account the marginal cost of public funds(MCF),which is the marginal welfare loss of taxpayers due to a marginal tax raise.The formula for optimal tolls on links is derived from the following conditions.One is MCF classified into two,not taking into account funding(MCF equal to-1)and pricing for funding(MCF does not equal-1).Another is tolls classified into two,pricing on all links(full link pricing),and pricing on a specific link(partial link pricing).Following the above conditions,this study succeeds in deriving the formula for optimal tolls on a full network with many links and nodes.Furthermore,this study indicates two calculation methods:one is to solve analytically or numerically for when the functional form of link flow demand is known.When the functional form is unknown,such as a perfect substitution case,it is necessary to carry out iteration until convergence:with the traffic assignment given the price level and with a change in price level based on the traffic assignment.

Macroscopic Fundamental Diagrams According to the Different Flood Depths on Probe Vehicle Data in Urban Bangkok

Impact of flood depth on traffic volume in two different zones of the Bangkok road network was investigated using traffic data obtained from probe vehicle trajectories.A Macroscopic Fundamental Diagram(MFD)was utilized to compare traffic flow rates across two road network zones in the city for a variety of flood depths,namely 0-5 cm,5-10 cm,10-15 cm,15-30 cm,and more than 30 cm.Results of empirical analysis over an observation period of one year as 2019 showed that flood depths had a strong correlation with the MFD parameters of free-flow speed,maximum flow,and traffic jam density.In particular,road floods greatly reduced average maximum flow across the inner city road network in Bangkok.Road floods had a significant impact on traffic characteristics of urban road networks.

Estimating freight production/attraction using nighttime satellite imagery

An appropriate understanding and accurate estimation of zonal freight production(FP)and attraction(FA)volume is one of the most important topics and the initial step in developing the origin and destination(OD)matrix.In general,zonal FP and FA are difficult to be obtained as observed data,particularly in developing countries,owing to the lack of large-scale freight surveys.Thus,several proxy indicators are often used for estimating FP and FA,such as the gross regional product(GRP),population,and the number of establishments.However,these indicators do not often estimate the zonal FP and FA accurately and are even not available readily.The nighttime light intensity(NLI)data that is human-induced light emission data and one of the open alternative data,possibly improves the accuracy of FP and FA estimation.However,few studies have examined the relationship between NLI and FP/FA.Therefore,the objectives of this study are to examine whether NLI can be a significant indicator for estimating zonal FP and FA relative to other socio-economic indicators and to examine the types of NLIs that can accurately estimate the FP and FA through a case study in Japan.As a result of the analysis,NLI data are identified as a significant variable for the estimation of FP and FA among various socio-economic variables.Although some of the indicators related to secondary industries provide higher accuracy,NLI exhibits better estimates than the popular indicators such as GRP and population.In addition,we propose three types of total NLI that multiply the unit NLI by the zonal area and this generates higher accuracy of unit NLI,the average light intensity of all pixels in a zone.We have also found that the use of habitable area for the estimation of total NLI provides the highest accuracy among the four types of NLIs including unit NLI.Through the analysis,NLI data is sufficiently applicable for estimating zonal FP and FA,relative to other important socio-economic indicators,although space transferability should be examined in other study areas.These findings could help estimating FP/FA particularly in countries and regions with limited statistical data available.