Hot-spot parking is becoming the Achilles' heel of the tourism industry. The more tourists that are attracted to the scenic site, the more often they will encounter a hassle of congestion to find a parking place; while those existing facilities for daily traffic are not supposed to support the excessive volume outburst. In this paper, we present a new parking guidance information system (PGI). By taking advantage of the technical advances of today in wireless communication of vehicular ad-hoc network, each vehicle will request and obtain a relatively fair opportunity to park. The competition and the corresponding allocation on the available slots emerging along the time scale are considered, in order to ensure that no vehicle enters a state of starvation. This is the first attempt to solve the spatiotemporal problem of resource assignment based on our extensive work on the Hungarian algorithm. The contribution as one part of the sustainable development of big historic cities is to minimize the idle driving and waiting, without increasing the parking supply, which could be costly and unnecessary to build in those urban areas. Both analytical and experimental results demonstrate the success of our effort, in terms of the average cruising/waiting time in each individual parking case and its upper bound. The data is compared with the best results known to date and shows a new direction to improve the resource assignment.