This paper describes the fundamental design and development of a new decision-support tool for time-based arrival metering, referred to as the En Route Descent Advisor (EDA). This automation is being developed at NASA Ames Research Center as a component of the Center-TRACON Automation System (CTAS). EDA computes advisories for the air-traffic controller to help deliver aircraft to an arrival-me...

The objective of this study is to determine whether ramp meters increase the capacity of active freeway bottlenecks, and if they do, how. The traffic flow characteristics at twenty-seven active bottlenecks in the Twin Cities have been studied for seven weeks without ramp metering and seven weeks with ramp metering. A series of hypotheses regarding the relationships between ramp metering and the...

The general purpose of this study is to develop both efficient and equitable freeway ramp control strategies. Measures of efficiency and equity for ramp meters are defined and applied to data collected in the Twin Cities ramp metering shut-off experiment. A trade-off between efficiency and equity is evident from the results of data analysis. A new time-dependent optimization program for the glo...

We deepen our previous analytical studies to include simulations, with special considerations on the effect that the metering mechanisms at the DiffServ boundary nodes have on differentiation. The two metering and marking mechanisms compared are token bucket and exponential weighted moving average (EWMA). The conjecture made in our analytical models is that the EWMA principle marks packets per ...

Understanding the behavior of weaving flows and estimating the effects of time-variant traffic conditions on the capacity of weaving areas is of critical importance in developing effective operational strategies, which can achieve the maximum utilization of existing capacity for a given freeway system. The previous phase of this research identified and classified the major weaving areas in the ...

-This paper describes the design, development and results from a high fidelity human-in-the-loop simulation of an integrated set of trajectory-based automation tools providing precision scheduling, sequencing and controller merging and spacing functions. These integrated functions are combined into a system called the Terminal Area Precision Scheduling and Spacing (TAPSS) system. It is a strate...

We have developed the first hardware and software (intellectual property) metering scheme that enables reliable low overhead proofs for the number of manufactured parts and copied programs. The key idea is to make each design slightly different during postprocessing phase. Therefore, if two identical hardware/software designs or a design that is not reported by the foundry are detected, the des...

Research recently conducted at the University of Central Florida involving crashes on Interstate-4 (I-4) freeway in Orlando, Florida led to the creation of new statistical and neural networks models that are capable of determining rear-end and lane-change crash risks along the freeway in real-time. For determining the rear-end crash risk, it was found that rear-end crashes occur within one of t...

Measurements taken downstream of freeway/on-ramp merges have verified that discharge flow diminishes when a merge becomes an active bottleneck. We show that metering the on-ramp can recover the higher discharge flow and thereby increase merge capacity. Detailed observations collected using video revealed that the outflow drop following activation was triggered by a queue that formed near the me...