Drivers in urban neighborhoods who cruise streets, seeking inexpensive on-street parking create a significant fraction of measured traffic congestion. The solution to this problem is to reduce the total traffic volume including cruising traffic by implementing a congestion pricing scheme: the imposition of a usage fee on a limited-capacity resource during times of high demand. We review the history of two alternatives for implementing congestion pricing scheme: road pricing (RP), which involves cordoning off a section of the center city and imposing a fee on all vehicles that enter it; and parking pricing (PP), which increases the costs of on-street and perhaps off-street parking. PP is needed in many environments where a significant fraction of drivers are simply cruising, looking for inexpensive on-street parking. In this paper, we propose a simple method to estimate the number of cruising drivers and the optimal parking price. Our survey in Boston shows that the number of cruising vehicles reaches 10-20% of the total number of parking spaces during peak hours and the required congestion charge (CC) for onstreet parking is at least about $1/ hour.

Drivers in urban neighborhoods who patrol streets, seeking inexpensive on-street parking create a significant fraction of measured traffic congestion. The pool of drivers patrolling at any time can be modeled as a queue, where ‘queue service’ is the act of parking in a recently vacated parking space and queue discipline is SIRO – Service In Random Order. We develop a queueing model of such driver behavior, allowing impatient drivers to abandon the queue and to settle for more expensive off-street parking. We then relate the model to the economic theory of congestion pricing, arguing that price differentials between on-street and off-street parking should be reduced in order to reduce traffic congestion. Reducing the number of "patrolling drivers" often can reduce urban road congestion significantly, in some cases as effectively as technologically expensive road pricing schemes that cordon off the center city.

Background: Among the indices able to replace invasive central venous pressure (CVP) measurement for patients with acute decompensated heart failure (ADHF) the diameters of the inferior vena cava (IVC) and their respiratory fluctuations, so-called IVC collapsibility index (IVCCI), measured by echocardiography, have recently gained ground as a quite reliable proxy of CVP.Objectives: The aims of our study were to compare three different ways of evaluating cardiac overload by using the IVC diameters and/or respiratory fluctuations and by calculating the inter-method agreementPatients and Methods: Medical records of patients hospitalized for right or bi-ventricular acute decompensated heart failure from January to December 2013 were retrospectively evaluated. The predictive significance of the IVC expiratory diameter and IVC collapsibility index (IVCCI) was analyzed using three different methods, namely a) the criteria for the indirect estimate of right atrial pressure by Rudski et al. (J Am Soc Echocardiogr. 2010), b) the categorization into three IVCCI classes by Stawicki et al. (J Am Coll Surg. 2009), and c) the subdivision based on the value of the maximum IVC diameter by Pellicori et al. (JACC Cardiovasc Imaging. 2013).Results: Among forty-seven enrolled patients, those classified as affected by persistent congestion were 22 (46.8%) using Rudski’s criteria, or 16 (34%) using Stawicki’s criteria, or 13 (27.6%) using Pellicori’s criteria. The inter-rater agreement was rather poor by comparing Rudski’s criteria with those of Stawicki (Cohen’s kappa=0.369, 95% CI 0.197 to 0.54), as well as by comparing Rudski’s criteria with those of Pellicori (Cohen’s kappa=0.299, 95% CI 0.135 to 0.462). Further, a substantially unsatisfactory concordance was also found for Stawicki’s criteria compared to those of Pellicori (Cohen’s kappa=0.468, 95% CI 0.187 to 0.75).Conclusions: The abovementioned IVC ultrasonographic criteria for hemodynamic congestion appear clearly inconsistent. Alternatively, a sequential or simultaneous combination of clinical scores of congestion, IVC ultrasonographic indices, and circulating levels of natriuretic peptides could be warranted.

Earlier methods in classic DEA investigate congestion for DMUs with crisp data. Although in real world we face data which are not crisp necessarily, available methods in this situation are not enough. In this paper for investigating congestion, a new method with fuzzy data has been promoted.In order to evaluate the performance of the method it is shown how our new method lead in exact results by an numerical example.