An Area Partitioning Approach to the Conflation of Road Networks with Highly Different Level of Details

A road network represents road objects in a given geographic area and their interconnections, and is an essential component of intelligent transportation systems (ITS) enabling emerging new applications such as dynamic route guidance, driving assistance systems, and autonomous driving. As the digitization of geospatial information becomes prevalent, a number of road networks with a wide variety of characteristics coexist. In this paper, we present an area partitioning approach to the conflation of two road networks with a large difference in level of details. Our approach first partitions the geographic area by the Network Voronoi Area Diagram (NVAD) of low-detailed road network. Next, a subgraph of high-detailed road network corresponding to a complex intersection is extracted and then aggregated into a supernode so that a high matching precision can be achieved via 1:1 node matching. To improve the matching recall, we also present a few schemes that address the problem of missing corresponding object and representation dissimilarity between these road networks. Numerical results at Yeouido, Korea's autonomous vehicle testing site, show that our area partitioning approach can significantly improve the performance of road network matching.

Improve urban traffic efficiency with prohibiting left-turn policy

Enhancing traffic flow plays an important role in the traffic management of urban arterial networks. The policy of prohibiting left-turn (PLT) at selected highly demanded intersections has been adopted as an attempt to increase the efficiency at these intersections. In this paper, we study the impact of PLT by mathematical analysis and simulations based on the cellular automaton model. Using the flow-density relation, three system performance indexes are examined: the average trip completion rate, the average traffic flow, and the average velocity of vehicles. Different route guidance strategies, including the shortest path and the quickest path, are investigated. We show that when left turn is prohibited, vehicles are distributed more homogeneously in the road network, and the system performs better and reaches a higher capacity. We also derive a critical length of link, above which the benefit of PLT will decrease.

The Impact of Digital Navigation on Travel Behaviour

Digital navigation – the combined use of satellite positioning, digital mapping and route guidance – is in wide use for road travel yet its impact is little understood. Evidence is emerging of significant changes in use of the road network, including diversion of local trips to new major road capacity and increased use of minor roads, which have problematic implications for investment decisions and for the management of the network. However, the ability of digital navigation to predict estimated time of arrival under expected traffic conditions is a welcome means of mitigating journey time uncertainty, which is one of the undesirable consequences of road traffic congestion. There is very little available information about the impact of digital navigation on travel behaviour, a situation that needs to be remedied to enhance the efficiency of road network operation.Digital navigation – the combined use of satellite positioning, digital mapping and route guidance – is in wide use for road travel yet its impact is little understood. Evidence is emerging of significant changes in use of the road network, including diversion of local trips to new major road capacity and increased use of minor roads, which have problematic implications for investment decisions and for the management of the network. However, the ability of digital navigation to predict estimated time of arrival under expected traffic conditions is a welcome means of mitigating journey time uncertainty, which is one of the undesirable consequences of road traffic congestion. There is very little available information about the impact of digital navigation on travel behaviour, a situation that needs to be remedied to enhance the efficiency of road network operation.

Predictive Intelligent Transportation: Alleviating Traffic Congestion in the Internet of Vehicles

Due to the limitations of data transfer technologies, existing studies on urban traffic control mainly focused on isolated dimension control such as traffic signal control or vehicle route guidance to alleviate traffic congestion. However, in real traffic, the distribution of traffic flow is the result of multiple dimensions whose future state is influenced by each dimension’s decisions. Presently, the development of the Internet of Vehicles enables an integrated intelligent transportation system. This paper proposes an integrated intelligent transportation model that can optimize predictive traffic signal control and predictive vehicle route guidance simultaneously to alleviate traffic congestion based on their feedback regulation relationship. The challenges of this model lie in that the formulation of the nonlinear feedback relationship between various dimensions is hard to describe and the design of a corresponding solving algorithm that can obtain Pareto optimality for multi-dimension control is complex. In the integrated model, we introduce two medium variables—predictive traffic flow and the predictive waiting time—to two-way link the traffic signal control and vehicle route guidance. Inspired by game theory, an asymmetric information exchange framework-based updating distributed algorithm is designed to solve the integrated model. Finally, an experimental study in two typical traffic scenarios shows that more than 73.33% of the considered cases adopting the integrated model achieve Pareto optimality.

ESTABLISHMENT OF A UNIFORM ROUTE GUIDANCE SYSTEM IN UKRAINE TAKING INTO ACCOUNT THE WORLD’S BEST PRACTICES TO IMPROVE ROAD SAFETY

Route guidance tools have a significant impact on road safety on public roads, as they carry important information on route guidance: provide drivers with information on the location on a specified road, regularly confirm the planned direction of movement, timely inform road users about the change of specified route direction and indicate the distance to the final object. This is very important information for the driver and it is difficult to overestimate it in road safety. Timely informing of drivers on the route direction will allow them carrying out adjustments in advance and feel confident on the road. Ensuring the completeness of route guidance information prevents emergency braking of vehicles in the area of traffic junctions and violation of the maneuvering rules to make a turn / turnaround in the right direction, and such maneuvers lead to road accidents. The establishment of a uniform route guidance system will reduce the road accident level and the cost of transportation due to excessive mileage of vehicles in the case of wrong route and help the drivers freely and easily get to their destination. The main need for information is felt by the drivers of vehicles whose actions directly impact the road safety. This, in turn, determines the basic principles and requirements for the composition, placement and choice of information tools. During the trip, the drivers need the information that would allow them navigating freely on the roads when passing the selected route that will relieve the stress of drivers and reduce the probability of road accidents, as well as increase the capacity of roads. It helps the drivers to adjust the previously selected route taking into account the real traffic conditions during the trip thereby minimizing the time consumption. To navigate the roads during movement, the drivers need the information about streets, objects and directions. Such information is provided by information signs, with which the road network must be equipped in sufficient quantity. The information provision should differ depending on the settlements, public roads and traffic conditions. A comprehensive solution of the issue of quality information provision to the road users can be achieved only by establishing a uniform route guidance system for road users which will take into account the needs for information of different categories of road users.