Bhargava Rama Chilukuri

The Distribution of Congestion on a Class of Stochastic Kinematic Wave Models

This paper shows that a wide range of stochastic extensions of the kinematic wave model tend to the same parameter-free expression for the probability of congestion at a given time-space point. This is shown for white noise initial density with deterministic and stochastic fundamental diagram in the case of Riemann problems and the bottleneck problem. It is also found that the stochastic solution i preserves the structure of the deterministic solution and ii tends to the deterministic solution with time at a given location.

SCOOT and incidents: Performance evaluation in simulated environment

SCOOT is a widely used adaptive signal control system. There have been many evaluations of SCOOT during normal traffic conditions. It is hypothesized that SCOOTs ability to adapt to varying traffic during incidents provides an added benefit over its normal congestion-relieving capability. Through an interface between CORSIM and an actual SCOOT system, this study evaluates, in a simulated environment, SCOOTs performance during incidents to quantify these additional benefits. The evaluation is made over a range of volumes and incident durations. A theoretical test network and two real-world networks are simulated. Network and intersection delay, travel time, and queue length are used as measures of effectiveness (MOEs) throughout the comparison to quantify total and marginal benefits. During a 45-min incident within the Salt Lake City downtown area network, SCOOT reduced network delay, travel time, intersection delay, and queue length by 28.3%, 22.8%, 30.7 %, and 24.2 %, respectively, relative to the optimized plan-based control. Similar results were observed on the other real-world network. Although adaptive control has benefits above plan-based signal control, the findings indicate that during incidents, SCOOT provides an additional increase in benefits. The findings indicate that average SCOOT MOEs improve by 7% for a 15-min incident, by 12% for a 30-min incident, and by 18% for a 45-min incident depending on congestion level. The additional benefits that SCOOT adaptive control provides during incidents are quantified through the systems inherent ability to respond to traffic conditions in real time.

Microsimulation-Based Framework for Freeway Travel Time Forecasting

This paper presents a microsimulation-based framework for generating short-term forecasts of travel time on freeway corridors. The microsimulation model that was developed replicated freeway capacity drop and relaxation phenomena critical for modeling non–steady state conditions. This framework was evaluated offline on a real-world freeway corridor by using data from manual counts and the Georgia Department of Transportations video detection system. The travel time forecasts were compared with ground truth travel time data; the comparison demonstrated the efficacy of this framework to produce realistic forecasts.