Optimizing distribution of metered traffic flow in perimeter control: Queue and delay balancing approaches

Perimeter traffic flow control based on the macroscopic or network fundamental diagram provides the opportunity of operating an urban traffic network at its capacity. Because perimeter control operates on the basis of restricting inflow via reduced green times at selected entry (gated) links, vehicles on those links may be subject to queuing and...

How many cars in the city are too many?: Towards finding the optimal modal split for a multi-modal urban road network

Interactions among different modes or vehicle classes in urban road networks affect the network performance in different and complex ways. Thus, an answer to the question of “how many cars are too many for a city?” is not trivial. However, multi-modal macroscopic fundamental diagrams (MFD) offer a novel opportunity to answer this question. So...

A Macroscopic Flow Model for Mixed Bicycle–Car Traffic

Bicycles are gaining popularity as a mode of transport resulting in a mixed bicycle–car traffic situation on urban roads. Cyclists however, are hardly included in traffic flow models which complicates the design of safe and congestion-free traffic situations. This work introduces class-specific speed functions based on two variables, being space...

Departure rates optimization and perimeter control: Comparison and cooperation in a multi-region urban network

With the renewed interest in the Macroscopic Fundamental Diagram (MFD) in the last decade, studies on network-level urban traffic control have increased in popularity. A popular urban traffic control approach is perimeter control, in which vehicle accumulation is kept below some critical accumulation value. An alternative control strategy is to...

Multi-lane Traffic Flow Model: Speed Versus Density Difference as Lane Change Incentive and Effect of Lateral Flow Transfer on Traffic Flow Variables

For better and more efficient motorway traffic control strategies on a lane level, accurate modelling and prediction of traffic conditions is essential. Existing real-time traffic state estimation methods aggregate traffic across lanes. Hence, there is a need for lane-specific traffic flow models. The majority of the existing macroscopic lane...

First order multi-lane traffic flow model – an incentive based macroscopic model to represent lane change dynamics

Unbalanced lane usage on motorways might lead to the reduction in capacity<br/>of the motorway. Lane-level traffic management present new opportunities<br/>to balance the lane-flow distribution and help reduce congestion.<br/>In order to come up with efficient traffic management strategies on a<br/>lane-level, there is a need for accurate lane...

Empirical MFDs using Google Traffic Data

<br/>The Macroscopic Fundamental Diagram (MFD) describes the relation between accumulation and speed in a zone. While theoretically expected, empirical validations have been done with limited numbers of floating car (e.g., taxi) data, and loop detectors. This paper will verify existence, shape and crispness of the MFD using Floating Car Data ...

Traffic-responsive signals combined with perimeter control: investigating the benefits

Empirical and research evidence suggests that traffic-responsive signal control strategies are generally not as efficient in over-saturated traffic conditions characterized by queue spillbacks. Recent studies on (MFD/NFD) have identified a destabilizing gridlock process that arises in congested networks which precludes efficient operation. The...

Using taxi GPS data for macroscopic traffic monitoring in large scale urban networks: Calibration and MFD derivation

A two-Fluid Model (TFM) of urban traffic provides the macroscopic description of traffic state. The TFMs parameters are hard to calibrate, particularly for the dynamic traffic conditions. This leads to the TFM often being used to compare the quality of service through the plot of stopping time versus trip time of the vehicles in the network....

Macroscopic Fundamental Diagram for pedestrian networks: Theory and applications

The Macroscopic Fundamental diagram (MFD) has proven to be a powerful concept in understanding and managing vehicular network dynamics, both from a theoretical angle and from a more application-oriented perspective. In this contribution, we explore the existence and the characteristics of the pedestrian Macroscopic Fundamental Diagram (p-MFD)...

Combination of traffic-responsive and gating control in urban networks: Effective interactions

Recent findings regarding macroscopic relationships of urban traffic measures such as the Macroscopic or Network Fundamental Diagram (MFD or NFD) have led to the development of novel traffic control strategies that can be applied at a network-wide level. One pertinent example is perimeter flow control (also known as gating or metering), which...

An Area-Aggregated Dynamic Traffic Simulation Model

Microscopic and macroscopic dynamic traffic models not fast enough to run in an optimization loop to coordinate traffic measures over areas of twice a trip length (50x50 km). Moreover, in strategic planning there are models with a spatial high level of detail, but lacking the features of traffic dynamics. This paper introduces the Network...

Traffic dynamics: Its impact on the macroscopic fundamental diagram

Literature shows that–under specific conditions–the Macroscopic Fundamental Diagram (MFD) describes a crisp relationship between the average flow (production) and the average density in an entire network. The limiting condition is that traffic conditions must be homogeneous over the whole network. Recent works describe hysteresis effects:...

Macroscopic Traffic Dynamics with Heterogeneous Route Patterns

This paper investigates at an aggregated (macroscopic) scale the effects of route patterns on a road network. Four main variables are considered: the production, the mean speed, the outflow and the mean travel distance. First, a simple network with heterogeneous travel distances between origins and destinationsis studied by simulation. It...

Data requirements for traffic control on a macroscopic level

With current techniques, traffic monitoring and control is a data intensive process. Network control on a higher level, using high level variables, can make this process less data demanding. The macroscopic fundamental diagram relates accumulation, i.e. the number of vehicles in an area, to the network performance, but only holds for situations...