• Journal of Korean Society of Transportation
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• v.30 no.6
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• pp.3-12
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• 2012

Additive willingness-to-pay (WTP) for leisure-travel time saving focused on the Iksan-Pohang Expressway and the Donghae Expressway was surveyed during the summer months to estimate the value of travel-time savings (VTTS) for non-business leisure trips. Travelers traveling between 2 and 3 hours on Iksan-Pohang Expressway had WTP of 723 won per 10 minutes of leisure-travel time savings and those traveling between 3 and 4 hours on Donghae Expressway had WTP of 854 won per the same. Based on this survey, we learned that WTP in leisure travel time savings increased with the total travel time. 300 effective samples for each expressway were collected, and estimation was separately conducted on the basis of Cox test.

• Journal of the Korean Society of Systems Engineering
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• v.19 no.1
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• pp.64-78
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• 2023

This paper introduces urban air mobility (UAM) and the definition and types of vertiports required for UAM operations. It also examines domestic policy trends related to UAM and identifies UAM routes in Seoul currently planned by the government. To do so, we reviewed prior research on vertiports, analyzed new regulations from the European Aviation Safety Agency, and studied domestic vertiport specifications and deployment plans for UAM operations based on the size of the S-A1 airframe being developed by Hyundai, and applied them to Samsung Station, the core area of the demonstration routes. Next, using the 'Travel Time Savings Ratio', a method for evaluating transportation economics, we compared and analyzed the time taken by passenger vehicles and the time saved by using UAMs to derive a highly economical demonstration route. As a result, the Samsung Station↔Cheongnyangri Station section was found to be the most efficient. These findings are expected to be utilized for adjusting the distribution of UAMs when operating the demonstration route in the future.

• Journal of Korean Society of Transportation
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• v.29 no.5
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• pp.121-138
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• 2011

More affordable and available cutting-edge technologies (e.g., wireless vehicle communication) are regarded as a possible alternative to the fixed infrastructure-based traffic information system requiring the expensive infrastructure investments and mostly implemented in the uninterrupted freeway network with limited spatial system expansion. This paper develops an advanced decentralized traveler information System (ATIS) using vehicle-to-vehicle (V2V) communication system whose performance (drivers' travel time savings) are enhanced by three complementary functions (autonomous automatic incident detection algorithm, reliable sample size function, and driver behavior model) and evaluates it in the typical $6{\times}6$ urban grid network with non-recurrent traffic state (traffic incident) with the varying key parameters (traffic flow, communication radio range, and penetration ratio), employing the off-the-shelf microscopic simulation model (VISSIM) under the ideal vehicle communication environment. Simulation outputs indicate that as the three key parameters are increased more participating vehicles are involved for traffic data propagation in the less communication groups at the faster data dissemination speed. Also, participating vehicles saved their travel time by dynamically updating the up-to-date traffic states and searching for the new route. Focusing on the travel time difference of (instant) re-routing vehicles, lower traffic flow cases saved more time than higher traffic flow ones. This is because a relatively small number of vehicles in 300vph case re-route during the most system-efficient time period (the early time of the traffic incident) but more vehicles in 514vph case re-route during less system-efficient time period, even after the incident is resolved. Also, normally re-routings on the network-entering links saved more travel time than any other places inside the network except the case where the direct effect of traffic incident triggers vehicle re-routings during the effective incident time period and the location and direction of the incident link determines the spatial distribution of re-routing vehicles.