MIDET: A Method for Indexing Traffic Events

Abstract

Traffic events announcements such as jams and road closures are continuously reported by mobile and Web applications. This collection of spatio-temporal data is an important source of information for urban planning, and can be used to orchestrate a number of actions to mprove the mobility, such as traffic control, traffic lights synchronization and preventive maintenance. Such analysis usually involves computation of spatial relationships among data, and may involve location of landmarks, roads and different types of events. In this paper, we propose a Method for Indexing Traffic Events (MIDET) for querying spatio-temporal data, whose location can be represented as a point or collection of points. MIDET is based on a fixed-grid space-oriented partitioning. In order to tackle the data skew, each grid cell is associated with a set of blocks containing event records. Moreover, a bitmap index is used for filtering out blocks without retrieving the actual data. MIDET provides the following benefits: adoption of a simple bulk loading process to manage dynamic insertion streams, and in-memory spatial joins. We conducted an experimental study using real data obtained from Waze. MIDET’s query performance was compared with Postgis, which adopts an R-tree index structure.

Um Sistema para Consultar Eventos de Trânsito Históricos do Waze

“…Estudos sobre diferentes formas de otimizar consultas que envolvem relacionamentos espaciais foram apresentados em [Chaudhry et al 2020] e [Mahmood et al 2019]. O diferencial do presente trabalho está no uso do modelo de armazenamento MIDET [Duarte et al 2021], que, diferente de outros trabalhos, foi projetado para consultar dados históricos. MIDET pode ser facilmente estendido para considerar duas características importantes de eventos de trânsito: a inserc ¸ão de dados em fluxo e o processamento paralelo e distribuído de consultas.…”

“…Este artigo apresenta um sistema para a consulta de eventos de trânsito históricos coletados pelo Waze, chamado de MIDET-IU. O MIDET-IU foi implementado utilizando o modelo de armazenamento de eventos MIDET [Duarte et al 2021], apresentado no SBBD 2021. Este modelo particiona a área de interesse em células geográficas (CGs) retangulares de tamanho fixo e utiliza indexac ¸ão baseada em Bitmaps.…”