This paper examines the conditions for which ramp metering can be bene®cial to the overall system in terms of travel time savings for a simple trac corridor that consists of a freeway and a set of parallel arterials connected by entrance ramps. The focus is on analyzing state and control relationships to arrive at general analytical results regarding optimal metering policies, rather than on e...

Non-recurrent congestion or incidents are detrimental to the operability and efficiency of busy urban transport networks. There exists multiple Automatic Incident Detection Algorithms (AIDA) to remotely detect the occurrence of an incident in highway or freeway scenarios, however very little research has been performed to automatically detect incidents in signalised urban arterials. This limite...

The goal of the study is to collect a comprehensive set of freeway and on-ramp operational data for the assessment of ramp metering systems. This paper is a presentation of data and initial findings for vehicle operations on loop ramps; a small subset of the larger project. The results reported here focus on the changes in modal activity (e.g. speed/acceleration) that occurred on two of the stu...

Freeway merging in congested traffic is a significant challenge toward fully automated driving. Merging vehicles need to decide not only how to merge into a spot, but also where to merge. We present a method for the freeway merging based on multi-policy decision making with a reinforcement learning method called passive actorcritic (pAC), which learns with less knowledge of the system and witho...

This paper addresses the problem of freeway traffic flow estimation. The freeway is considered as a network of components representing different freeway stretches called segments. The evolution of the traffic in a segment is modelled as a dynamic stochastic system, influenced by states of neighbour segments. Measurements are received only at boundaries between some segments and averaged within ...

This study uses regression analysis to evaluate long-run traffic management system performance. Three important traffic management systems in the Twin Cities metro area—Ramp Metering, Variable Message Signs, and Freeway Service Patrols (the Highway Helper Program) were evaluated using multiple regression models to predict link speed and incident rate. We find that ramp meters increase freeway l...

Ramp metering has been recognized as an effective freeway management strategy to either avoid or ameliorate freeway traffic congestion by limiting access to the freeway. California has applied ramp metering widely in major metropolitan areas. Currently, California has three major ramp metering systems: San Diego Ramp Metering System (SDRMS), Semi-Actuated Traffic Management System (SATMS), and ...

This study presents a mixed integer model for an integrated control between off-ramp and arterial traffic flows. The proposed study intends to minimize the queue spillback from offramp to the freeway mainline that may significantly degrade the performance quality of the entire freeway system. In this study, the Cell Transmission Model (1, 2) is employed to capture the traffic propagation on bot...

Traffic conditions vary over time, and therefore, traffic behavior should be modeled as a stochastic process. In this study, a probabilistic approach utilizing Autocorrelation is proposed to model the stochastic variation of traffic conditions, and subsequently, predict the traffic conditions. Using autocorrelation of the time series samples of density and flow which are collected from segments...

When implementing ramp metering in the context of freeway networks, traffic can spontaneously re-route due to the applied control actions. Although this re-routing can have an important impact on the resulting traffic situation in the traffic network and on the performance of the traffic network as a whole, re-routing is not automatically included in current model predictive frameworks for free...