Project

The amount of vehicles and therefor the density of roads increased a lot in the Netherlands. Controlling the traffic at a network scale became very important. Due to increasing congestion on the Dutch roads, the demand for road capacity increases. To increase the amount of road capacity, new infrastructure could be build. The costs for this solution are however very high. Instead of new infrastructure, a better utilisation of the existing infrastructure could cope with this problem. A better utilisation of the existing infrastructure can be reached by carrying out dynamic traffic management (DTM). DTM is however more efficient for… Read More »Controlling sub-networks with MFD

Ring roads around major cities are intensively used, and congestion is often a problem. On these expressways congestion can back-propagate onto connecting freeways, and via on-ramps onto the urban road network . It is therefore beneficial to be able to suppress the growth of congestion or even prevent the onset of it as much as possible. Implementing route guidance is a means to steer the network state away from bad traffic conditions. Finding the optimal route guidance settings is a complex task. A proactive approach implies the need for prediction, as the traffic conditions are constantly changing and control actions… Read More »Proactive route guidance on a ring road using a decentralized control algorithm

During the past decades, the number of cars on the road and the need for transportation has increased rapidly. Those increasing traffic volumes lead to an increase of congestion, reduced safety and an increase in pollution. Recent numbers show that there has been an increase of 16% between 2000 and 2012 in the amount of traffic on Dutch roads. It is expected that this growth continues will continue. The costs of congestion and delays are estimated to be between 1.8 and 2.4 billion euro per year. The easiest way to increase road capacity is to build more roads, which has been… Read More »Prevent congestion using dynamic speed limits

Traffic congestion on freeways is a serious problem in most countries, with manifold adverse effects − from lost vehicle hours, fuel overuse to emissions. Empirical researches have attributed higher traffic demand, bottlenecks and disturbances from individual driver behaviour as the key interplaying causes for a breakdown in traffic. As adding extra infrastructure on one hand is often dismissed as a financially or spatially unviable alternative, and on the other has been scientifically known to induce more demand, traffic management and control have assumed great importance today. Dynamic control using variable speed limits (VSL) has been a promising approach for mainstream control of traffic to prevent and resolve… Read More »Integrating roadside speed control with ramp metering

Currently the traffic managers base their decisions mainly on experience: they implicitly estimate the traffic state at hand and the expectation in the near future by means of several data sources. Examples of these data sources are the roadside cameras, loop detectors and road works information. In this way they select the right predefined scenario and associated measures to control the traffic operations. However, in the future this method will not provide sufficient results. The decision making process will become more complex: more data will become available from different sources in different forms (e.g. travel time camera’s, individual speed data… Read More »Short-term prediction of traffic operations in traffic control centers

Congestion is probably the main problem in highways, not only in the Netherlands, but worldwide as well. The reasons it occurs vary from case to case; high demand disproportionate to the infrastructure, accidents or frequent lane changes. The latter, and more specifically merging at on-ramps, will be further analysed in this project. Merging at on-ramps can cause disruptions to the traffic flow. Merging behaviour differs from driver to driver; others merge too soon, others too late. Merging is based on gap acceptance, which is the gap between two vehicles already on the highway that is accepted by the merging vehicle;… Read More »Optimising weaving behaviour through ITS

Traffic control measures aim at improving traffic conditions. Traffic control measures have been implemented and tested in practice. One of the most effective control measures is ramp metering. Ramp metering is a traffic control measure which regulates the inflow from the on-ramp to the mainline of the freeway. Ramp metering has been implemented a lot in practice and recently even in a large Field Operational Test (FOT): the PraktijkProef Amsterdam (PPA). Ramp metering uses a certain algorithm to optimize the traffic throughput on the freeway and to prevent the capacity drop. Over the years several different algorithms have been developed… Read More »Optimal adaptive control approach for ramp metering

In practice, microscopic traffic simulation models are often used for the analysis and management of transport systems. These models simulate the movement of individual vehicles by using a carfollowing model for the longitudinal behaviour of drivers and lane change model for their lateral behaviour. However, current lane change models cannot simulate all driving behaviour that is seen in reality. Therefore, recent work has studied driving behaviour by means of driving experiments in combination with interviews to get insight in motives behind driving behaviour. This work revealed that drivers apply four different lane change strategies when driving on motorways: 1. Speed… Read More »Strategies for lane change choice

It needs to be noted that there is not one definition for unbundling (separation of traffic flows). However, the main principle of separating traffic flows is that flows do not intersect and therefore at least one of the flows can retain its level of service. In situations where traffic flows intersect, it is possibe that capacity drops or dangerous situations occur due to differences in speed. These are also the main reasons for applying unbundling. Many reports focus on one specific way of unbundling; collector-distributor lanes, express lanes, bus lanes, freight traffic lanes or bicycle paths. These all are examples… Read More »Separating traffic flows: when and how?

As automated vehicles on public roads become more common, road authorities have to consider action to facilitate their introduction. A main challenge lies in the largely unknown effects of the introduction of automated vehicles on mixed (conventional and automated) traffic. Given the financial advantages for carriers, an area where this challenge is especially urgent is truck platooning. Truck platooning is defined as two or more trucks driving at reduced inter-vehicle gaps (typically less than one second) enabled by wireless vehicle-to-vehicle communication and of which both longitudinal and lateral control are automated. Motorways will be the first road type where automated… Read More »Effects of truck platooning at motorway on-ramps