ETH-Forschende zeigen auf, dass sich die Verkehrskapazität von Städten anhand der Struktur ihres Strassennetzes vorhersagen lässt. Mit diesem Wissen können Stadtplanerinnen und Stadtplaner künftig quantitativ bestimmen, wie bauliche Eingriffe die Verkehrsleistung beeinflussen. Artikel in den ETH News
Traffic in an urban network becomes congested once there is a critical number of vehicles in the network. To improve traffic operations, develop new congestion mitigation strategies, and reduce negative traffic externalities, understanding the basic laws governing the network’s critical number of vehicles and the network’s traffic capacity More
The macroscopic fundamental diagram provides insights on traffic flow at a macroscopic level. Given its elegance, it has become a popular tool to analyse various traffic-related problems. We show that the MFD can also be used to estimate the level of heterogeneity in a network, which allows city planners the More
The platooning of trucks has been considered in many studies as a potential approach to reduce some of the negative effects caused by trucking on the highways. A platoon of trucks is formed by decreasing the spacing between the trucks and adjusting their speeds at the same time. More
In urban environments, where buses and cars operate in mixed fashion, bus delays can be exacerbated at signalized intersections due to the interactions with cars. This research will investigate the use of additional signals to provide priority to buses at signalized intersections, while minimizing the negative effects to More
In the last decades, cities around the world have started to reduce speed limits in both residential areas and city centers. In Switzerland, for example, more than 700 districts and municipalities have streets and areas with 30 km/h regulations, and there have been initiatives to extend those to More
To understand the physics of urban mobility, traffic dynamics of multimodal urban networks need to be analyzed under many different scenarios, including various network properties. To this end, an aggregated model for multimodal systems, following the concept of the three-dimensional bi-modal macroscopic fundamental diagram (3D-MFD), can be used More
The development in connected and automated vehicles provides more flexibility in the monitoring and control of traffic systems. Equipped with communication systems and various sensors, connected and automated vehicles can communicate with the infrastructure to report real-time information, such as location, speed, etc. Moreover, the automated driving system More
In: Transportation Cruising-for-parking is a common phenomenon in urban areas worldwide. Properly understanding and mitigating cruising can reduce travel times, alleviate traffic congestion, and improve the local environment. In this paper, we present a case study of the city of Zurich, using a macroscopic model to analyze the current More
In: Transportmetrica B: Transport Dynamics. S.1-21. Mehr This paper studies traffic behaviour on one-way, two-way and two-way streets with prohibited left turns using three different methods; analytical formulations, static traffic assignment and microsimulation. While two-way networks result in shorter routes, one-way networks increase intersection throughput. Two-way networks without left More
In: Transportation Research Part C: Emerging Technologies, 77. S.257-274. Mehr Recent years have seen a renewed interest in Variable Speed Limit (VSL) strategies, and their potential as a freeway metering mechanism or a homogenization scheme. This paper uses empirical data to examine both the macroscopic and microscopic effects More
In: Transportation Research Part C: Emerging Technologies, Volume 72, November 2016. S.109-129, ISSN 0968-090X. More This paper proposes an efficient signal control algorithm under the co-existence of conventional vehicles, connected vehicles and automated vehicles. Trajectories of the automated vehicles are modified to reduce delay and stops. Simulations show that both More
In: Journal of Advanced Transportation, 50 (4). S.406-420. PDF More An on-street parking maneuver often starts a temporary bottleneck, leading to additional delay endured by the following vehicles. If the maneuver occurs near a signalized intersection, the service rate of the intersection might be reduced. In this paper, a More
In: Transportation Research Part C: Emerging Technologies, 64. S.28-44. More The paper establishes the first real-time control algorithm for pre-signals. The algorithm combines multiple operation strategies at the intersection. It functions well with a wide range of input values and is robust to input errors. The real-time pre-signal minimizes person More
In: Accident Analysis & Prevention, 85. S.219-228. Mehr One of the challenges in traffic safety analyses is the heterogeneous nature of safety data. The study suggests that latent class clustered regression approach is suitable for reducing heterogeneity and revealing important hidden relationships in traffic safety analyses.
In: Transportation Research part B: Methodological. Mehr PDF The urban parking and traffic systems are essential components of the overall urban transportation structure. The interactions between them can be highly influential to their performance. Here, we propose a methodology to model macroscopically such interactions and evaluate their effects on More
In: Transportmetrica B: Transport Dynamics. DOI 10.1080/21680566.2015.1025892 Mehr The paper evaluates the trade-offs between loop detector data and floating car data for the real-time estimation of origin–destination matrices in small networks. Results are used to evaluate the trade-offs between loop detector coverage and the penetration rate of floating car More
In: Transportation Research Record: Journal of the Transportation Research Board (accepted or in press). More This paper analyses traffic performance on an abstract grid network with different street configurations using the Network Exit Function (NEF) – an aggregate relationship between trip-completion rate and the number of vehicles circulating in a network.
In: Accident Analysis & Prevention, 72. S.330–340. Mehr This study is based on a five-year national pedestrian safety dataset for Switzerland. It explores the application of a partial proportional odds (PPO) model to bridge the gap between conventional crash injury severity models. The study shows that PPO models More
Transportation Research Part C, 46. S.121-131. Mehr Information from connected vehicles, such as the position and speed of individual vehicles, can be used to optimize traffic operations. An algorithm for two one-way-streets is proposed to gain insights about the value (in terms of delay savings) of using connected More
Transportation Research Record. PDF ECitation One of the major causes of bus delays in urban environments are signalized intersections. The use of a pre-signal has been proposed in order to utilize the full capacity of the main signal while still providing bus priority. The goal of this research More
Transportation Research Record, 2359, 1-9. Mehr Parking duration is an important element in reflecting the parking demand, very often a patrol survey is conducted to obtain the data. This paper introduces an analytical model to understand the effects of survey cost and other inputs on survey accuracy in a More
In: Reliability Engineering & System Safety, 162. S.28-39. PDF A non-parametric approach is proposed for qualitative sensitivity analysis (i.e., screening) of dependent inputs. Numerical experiments show that it can properly identify the influential inputs. Its low computational cost but high accuracy makes it practical for the initial screening More
An on-street parking manoeuvre can often start a temporary traffic bottleneck. When the manoeuvre occurs at a close distance upstream a signalized intersection, the intersection might be starved for traffic due to the parking manoeuvre and a part of the intersection capacity is wasted. In this project, the More
Cities all over the world are struggling with congestion problems and its negative impacts. Zurich for example restricts the access to the inner city through a traffic lights control system in order to reduce congestion. The Traffic Engineering Group of the Institute for Transport Planning and Systems (IVT) More
Cities across the world are starting to recover space, previously devoted to cars, for other uses. The main purpose of this project was to better understand the removal of space in urban settings and to provide some analytical results showing that it is possible to remove streets from More
The goal of this project was to evaluate the data requirements for a possible implementation of a macroscopic fundamental diagram (MFD) control scheme in an urban area. Particularly, we have studied the accuracy of MFDs created using only a percentage of the links (i.e., streets). This is especially More
Current VSS standards for the design and evaluation of uncontrolled intersections only take into account conflicts between private vehicles. Unfortunately, this limits the applicability of the standards in most Swiss urban networks, as they cannot be used to model other modes such as public transport, pedestrians, or bicycles. More
The MULTITUDE is a joint research project funded by the European Union COST programme (COST Action TU0903). The main objective was to develop, implement and promote the use of methods and procedures for supporting the use of traffic simulation models, especially regarding model calibration and validation, to ensure More
In patrol surveys, patrolling observers check the parking area every δ minutes (i.e., at fixed time intervals) and record the plate number of the car occupying each stall. To find the average parking duration, an estimated value is obtained by averaging the parking duration of each car observed. More
The City of Zürich acquired «Verkehr In Städten – SIMulationsmodell» (VISSIM), a microscopic multi-modal traffic flow simulation software, to effectively model traffic within the city. VISSIM is a widely used simulation software with many applications and high potential. However, like other commercial microscopic traffic simulation software, VISSIM has a More
In October 2010, Monica Menendez was appointed Director of the Traffic Engineering Research Group of the Institute for Transport Planning and Systems at ETH Zurich. Prior to that, she was a Management Consultant at Bain & Company’s San Francisco office. She joined Bain after receiving a MSc and a PhD in Civil and Environmental Engineering from the University of California, Berkeley in 2006. Her research interests include traffic flow theory and operations, sustainable transportation, and logistics.