Trip Planning Queries in Road Networks

机动性是人类的基本特征。作为一个物种，我们总是为了太多的原因而迁徙。随着当今移动通信设备的丰富，有关移动性的数据可以相对容易地收集，从而提供大量的时空数据。智能地使用这些数据可以使人们在几个方面更有效率地出行，例如，通过更有效和高效地拼车来消耗更少的燃料，减少交通时间等等，从而走向所谓的智能城市。大量的流量监控应用、社交网络等可以利用这些数据源，并为其聚集更多的价值。此外，通过考虑非时空数据，例如公共事件、天气模式和路径受欢迎程度，这些数据可能变得相当复杂和丰富。鉴于这一总体主题，拟议的研究计划将集中在公路网中的出行计划查询这一主题。旅行计划查询考虑道路网络、起点和终点以及旅行者(或其组)想要访问的一组兴趣点。旅行计划查询可以有几种变型：兴趣点可以属于不同的兴趣点类别(可能需要以任意的、完全的或部分的顺序遍历)，或者可能必须考虑兴趣点的开放时间以及交通状况或公共交通时间表，兴趣点之间或从预定路径到潜在兴趣点的最大距离，*拟议的研究方案将通过研究旅行计划查询的三个相关方面，有助于推动旅行计划查询领域的总体发展：(A)多式联运。到目前为止，在文献中，绝大多数旅行计划查询都考虑了单一的交通方式。考虑到旅行者在一次旅行中使用一种以上交通方式的可能性具有重要的现实意义。(B)丰富的道路网。公路网本身相对简单，也很容易理解。尽管如此，可以从它们的上下文环境和它们的历史使用中考虑大量信息，以便丰富它们并提供语义上更有趣的答案。(C)时间依赖性。时间是计划中的一个内在因素，例如，旅行时间在一天/一年中有所不同，旅行者可能需要考虑特定的出发或到达时间。这些方面在旅行计划查询中没有得到广泛考虑。此外，鉴于这些方面的普遍重要性，无论是单独的还是合并的)，加深对这些方面的理解将有助于广泛界定的时空研究中的知识体系，并使这些方面能够与其他查询相关联地加以考虑。

Mobility is a basic human characteristic. As a species we have always been moving about for a plethora of reasons. With today's abundance of mobile communication devices, data about mobility can be collected relatively easily, thus providing large amounts of spatio-temporal data. Using such data intelligently can enable people to move more efficiently in several aspects, e.g., consuming less fuel by sharing rides more effectively and efficiently, spending less time in traffic, etc., thus moving towards so-called smart cities. A large number of traffic monitoring applications, social networks, etc., can leverage such data sources and aggregate further value to it. Moreover, this data can become rather complex and richer by considering non-spatio-temporal data, e.g., public events, weather patterns and path-popularity. Given this overarching theme, the proposed research program will focus on the topic of trip planning queries in road networks. A trip planning query considers a road network, a starting and a destination point, and a set of points-of-interest a traveller (or group thereof) wants to visit. There can be several variations of trip planning queries: points-of-interest may belong to different categories-of-interest (which may be needed to be traversed in an arbitrary, full or partial order) or one may have to account for opening hours of points-of-interest along with traffic conditions or public transportation schedules, maximum distance between point-of-interest or from pre-determined paths to potential points-of-interest, etc. ******The proposed research program will contribute to advancing the state-of-the-art in the domain of trip planning queries in general by investigating three relevant aspects thereof: (a) Multi-modal transportation. Thus far in the literature, the vast majority of trip planning queries have considered a single mode of transportation. It is of practical importance to consider the possibility of travellers using more than one transportation mode in a single trip. (b) Enriched road networks. Road networks themselves are relatively simple and well understood. Nonetheless, there is a large amount of information that can be taken into account from their contextual environment as well as their historical use in order to enrich them and provide semantically more interesting answers. (c) Temporal dependency. Time is an intrinsic factor in planning, e.g., travel times vary during the day/year and travellers may need to consider a particular departure or arrival time. Those aspects have not been widely considered in the context of trip planning queries. Furthermore, given the general importance of those aspects, individually or in combination), furthering their understanding will contribute to the body of knowledge in spatio-temporal research broadly defined and enable the consideration of those aspects with respect to other queries as well.**