Daniel Dailey

University of Washington Seattle | UW · Department of Electrical Engineering

This paper presents a new multidimensional framework for modeling car-following based on statistical evaluation of work zone and non-work zone driver behavior. The models developed as part of this multidimensional framework are based on psycho-physical concepts for car-following which are close in character to the Wiedemann model used in popular tr...

This paper presents a new multidimensional framework for modeling car-following based on statistical evaluation of work zone and non-work zone driver behavior. The models developed as part of this multidimensional framework are based on psycho-physical concepts for car-following which are close in character to the Wiedemann model used in popular tr...

The design of mini-roundabouts has been around and practiced in Europe for decades. It has been a successful and low-cost intersection configuration using existing external boundaries of intersections. Nevertheless, accessible traffic capacity models for mini-roundabouts do not exist. This study provides design recommendations and a simulation appr...

This paper presents the concept of a Living Laboratory (LL) and how it is applied to transportation operations research through a case study. This case study focuses on calibrating the Wiedemann car-following model parameters specific to freeway work zones. Applying the concept of a LL enables the experimental platform to be in a natural real-world...

This paper focuses on the experimental aspect of short range communication between a moving vehicle and a stationary receiver. The accumulated measurements of signal to noise ratio fit a single line of site model rather well with the implication that the communications channel will function best as the distance between the radios is reduced. Howeve...

In this paper we present a simplified model for traffic management cameras and a calibration method based on a known distance along the road. We then describe how to estimate this interval from the images using an autocorrelation method applied to lane marker features. Assuming the camera has been calibrated and the vehicle lanes have been identifi...

This paper develops a quantitative relationship between Nexrad radar reflectivity and surface traffic conditions. Data from two data mines on the University of Washington campus are combined to evaluate the quantitative relationship between freeway speed reduction and rain fall rate as measured by Doppler radar. Radar data are converted into rainfa...

Traffic models have frequently been used to evaluate (1) traffic management systems, (2) traffic control schemes, and (3) automated vehicle routing, as well as for planning purposes. Simulation-in-the-loop control is presently used in control schemes where the processes internal to the plant model are not easily reduced to analytical equations. Thi...

Extracting quantitative measures from roadway camera images requires calibration of the camera. Roadway features such as fog lines and lane boundaries can provide the information necessary to calibrate the cameras on the fly. In addition, "straightening" the image allows for linear measurements in the image which in turn allows the use of linear co...

The Washington State Department of Transportation (WSDOT) operates a central traffic management system used for both day-to-day surveillance as well as for traveler information. In King county real-time traffic speed information is created using virtual sensors based on tracking transit vehicles. In order for this new information source to be merge...

The Washington State Department of Transportation (WSDOT) has a network of several hundred CCTV traffic surveillance cameras deployed on the freeways and arterials around Seattle for congestion monitoring. However, these cameras are not calibrated and can be panned, tilted and zoomed. This paper presents a novel method of automatically computing en...

In this paper we present a simplified model for traffic management cameras and a calibration method based on a known distance along the road. We then describe how to estimate this interval from the images using an autocorrelation method applied to lane marker features. Assuming the camera has been calibrated and the vehicle lanes have been identifi...

An algorithm to estimate speed from traffic surveillance cameras in a variety of traffic congestion, weather, and lighting conditions is presented. The features from the images are projected into a one-dimensional sub-space and transformed into a linear coordinate system by using a simplified camera model. A cross-correlation technique is used to s...

Assuming a standard pinhole camera model, we show that there is a calibrating "scale factor" and a simple formula that relates the change in distance along a line parallel to the highway direction to a change in the image vertical coordinate. Using this scale factor, we can estimate vehicle speeds by tracking vehicle images in successive time-tagge...

In past work we described a system of components that are used to construct transit traveler information applications. In this paper we describe an ongoing project that uses the same component architecture to combine maps, schedules, and AVL information from four transit agencies. The result is a set of Web applications suitable for both transit ma...

In this paper, we present a new three-stage algorithm to calibrate roadside traffic management cameras and track vehicles to create a traffic speed sensor. The algorithm first estimates the camera position relative to the roadway using the motion and edges of the vehicles. Given the camera position, the algorithm then calibrates the camera by estim...

In this paper, we present a statistical method to extract images of passenger cars from highway traffic scenes. The expectation-maximization (EM) algorithm is used to classify the vehicles in the images as either being passenger cars or some other bigger vehicles, cars versus non-cars. The vehicle classification algorithm uses training sets of 100-...

In this paper we present a general prescription for the prediction of transit vehicle arrival/departure. The prescription identifies the set of activities that are necessary to preform the prediction task, and describes each activity in a component based framework. We identify the three components, a Tracker, a Filter, and a Predictor, necessary to...

A new algorithm is presented for estimating speed from roadside cameras in uncongested traffic, congested traffic, favorable weather conditions, and adverse weather conditions. Individual vehicle lanes are identified and horizontal vehicle features are emphasized by using a gradient operator. The features are projected into a one-dimensional subspa...

An algorithm is presented for correcting errors in archived loop data from freeway traffic-management systems that are the result of poorly calibrated sensors. These errors pose a significant difficulty when archived data are used in off-line analysis because the calibration errors are difficult to detect by using traditional methods. In the presen...

A corridor approach to travel-time estimates by using transit vehicles as probes is presented. These estimates increase the information density along the corridor, compared with use of only probe information at specified points. Speed estimates are provided that track the significant changes identified in inductance-loop data, but the estimate of t...

The wide variety of remote sensors used in Intelligent Transportation Systems (ITS) applications (loops, probe vehicles, radar, cameras, etc.) has created a need for general methods by which data can be shared among agencies and users who own disparate computer systems. In this paper, we present a methodology that demonstrates that it is possible t...

In this paper, we present an algorithm to estimate mean vehicle speed from un-calibrated roadside cameras. The algorithm presented creates a new virtual speed sensor that leverages the large numbers of low quality cameras already installed by transportation agencies. The calibration problem considered here is complicated by the ability of the opera...

We present an algorithm to calibrate roadside traffic management cameras to create a traffic speed sensor. We present a simplified camera model that can produce good single vehicle speed estimates.

In this paper, we present an algorithm to detect scene change that indicates that camera re-calibration is necessary. This work is in support of using un-calibrated traffic management roadside cameras for automated speed estimates. We construct an activity region using moving vehicle edges, and small differences in the activity region in consecutiv...

In this paper, we present algorithms that use transit vehicles as probes for determining traffic speeds along freeways and other primary arterials. We describe a system of "virtual" probe sensors that measure transit vehicle speeds using automatic vehicle location system (AVL) tracking data. Examples showing the correlation between probe data and i...

A transit vehicle information system that delivers estimated departure times for buses at user-selectable geographic locations to Internet-enabled mobile devices is reported. The system is not merely schedule based; it makes use of real-time vehicle position reports to predict travel times to future locations. How the physical restrictions of mobil...

An algorithm with which to estimate mean vehicle speed from roadside cameras owned by a traffic management agency is presented. These roadside cameras are not calibrated nor are calibration marks available in the scene. However, estimating camera calibration coefficients is the most important step in extracting quantitative information about the th...

We report the overall use patterns for a transit application that features graphical positioning of transit buses in real-time. Its purpose is to provide information to travelers that is not available from static schedules and thereby allow them to make better, informed travel decisions. Busview is accessed via the World Wide Web. Analysis of Web s...

We report on a real-time transit vehicle information system which delivers content to Internet-enabled mobile devices, such as cell phones. The content is in the form of predicted arrival/departure times for buses at user-selectable geographic locations within a transit region. We discuss how the physical restrictions of such devices, e.g., screen...

The design and implementation of a distributed transit vehicle information system is presented. The system, which is called Busview, delivers real-time transit vehicle location data to the traveling public via the World Wide Web. The data is presented in graphical format on a variety of display windows. Functionality of the program is described, an...

The Smart Trek Model Deployment Initiative, a US Department of Transportation-funded intelligent transportation systems program in the Puget Sound region, has made great strides in integrating and disseminating traveler information. The initiative focuses on real time information to help travelers make informed decisions about their travel options....

New algorithms are presented that use transit vehicles as probes for determining traffic speeds and travel times along freeways and other primary arterials. A mass transit tracking system based on automatic vehicle location data and a Kalman filter used to estimate vehicle position and speed are described. A system of virtual probe sensors that mea...

An algorithm is presented to predict transit vehicle arrival times up to 1 h in advance. It uses the time series of data from an automated vehicle location system, consisting of time and location pairs. These data are used with historical statistics in an optimal filtering framework to predict future arrivals. The algorithm is implemented for a lar...

The creation and use of an intelligent transportation systems archived data user services data mine that is available on the World Wide Web are described. The transportation infrastructure in the Seattle metropolitan area is instrumented with thousands of inductance loops. The data from these loops can be used in a variety of modeling and transport...

We present a novel approach to estimate traffic speed using a sequence of images from an uncalibrated camera. We assert that exact calibration is not necessary to estimate speed. Instead, we use: 1) geometric relationships inherently available in the image, 2) some common-sense assumptions that reduce the problem to a one-dimensional geometry, 3) f...

This paper presents an algorithm to predict transit vehicle arrival times up to an hour in advance. The time series of data from an automated vehicle location system, consisting of time and location pairs, is used with historical statistics in an optimal filtering framework to predict future arrivals

The Seattle model deployment initiative has created a new technology for data sharing in an ITS environment. This technology, the ITS Backbone that uses Self Describing Data (http:/ /www.its.washington.edu/bbone/), creates a framework in which to build applications. These applications use Self Describing Data (SDD) to obtain real-time data over the...

Presented is a new algorithm for estimating speed by using a sequence of video images from an uncalibrated camera. An assertion is made that exact calibration is not necessary for estimating speed. Instead, the following are used to propose a novel method that extracts scale information and estimates speed: (a) geometric relationships inherently av...

Performance monitoring is an issue of growing concern both nationally and in the state of Washington. Travel times and speeds always have been of interest to traveler information researchers, but there is limited infrastructure with which to collect such data on a continuous basis. Transit vehicles were used as probes, and a framework was developed...

This paper presents an algorithm for estimating travel time using volume and occupancy data from a series of single inductance loops. The algorithm is based on the statistics of the measurements obtained from a traffic management system. The algorithm produces an estimate of speed and travel time as well as providing a reliability test for the spee...

Seattle Smart Traveler (SST) is a world wide web (WWW) application designed to test the concept of "dynamic" rideshare matching. SST collects spatial and temporal trip information using a series of WWW pages, performs a match using SQL specifications to a database engine, and supports both the standard phone-based contact methodology as well as two...

This report describes two phases of the development of the Busview project. The first phase was done as a research project and designed principally for University of Washington campus users. The second phase was the construction of a Java applet to make an expanded version of the information available to a regional audience. The report is effective...

This paper provides an overview of the Seattle Wide-area Information for Travelers (SWIFT) project. The SWIFT project delivers traffic and traveler information via FM subcarrier to hand-held wireless devices as well as in-vehicle devices. SWIFT is an unusual public/private partnership in which the public sector takes the responsibility for obtainin...

This paper presents an algorithm for estimating mean traffic speed using volume and occupancy data from a single inductance loop. The algorithm is based on the statistics of the measurements obtained from a traffic management system. The algorithm produces an estimate of speed and provides a reliability test for the speed estimate.

Seattle Smart Traveler (SST) is an application of World Wide Web (WWW) technology to test the concept of automated dynamic rideshare matching. In SST, the rideshare clientele interact with the rideshare system using only WWW pages. SST collects spatial and temporal trip information using a series of WWW pages, performs a match using structured quer...

Seattle Smart Traveler (SST) is an application of World Wide Web (WWW) technology to test the concept of automated dynamic ride-share matching. This paper reports a new statistical model for quantifying ride-share matching and car pooling. The model is validated using the SST experimental results, and the model demonstrates that the car-pooling pro...

We present an algorithm to estimate speed using a sequence of video images from an uncalibrated camera. The algorithm uses frame differencing to isolate moving edges and track vehicles between frames. The algorithm uses a known vehicle length distribution with image information to estimate speed

This paper presents an algorithm for predicting the arrival time of transit vehicles using a combination of both AVL and historical data. The algorithm is presented in its two components: tracking (using a Kalman filter framework) and prediction (using statistical estimation). The algorithm produces an estimate of the predicted arrival time for a g...

This paper presents an algorithm for estimating mean traffic speed using volume and occupancy data from a single inductance loop. The algorithm is based on the statistics of the measurements obtained from a traffic management system. The algorithm produces an estimate of speed and provides a reliability test for the speed estimate.

The wide variety of remote sensors used in intelligent transportation systems (ITS) applications (loops, probe vehicles, radar, cameras, etc.) has created a need for general methods by which data can be shared among agencies and users who own disparate computer systems. In this paper a methodology is presented that demonstrates that it is possible...

The wide variety of remote sensors used in intelligent transportation systems (ITS) applications (loops, probe vehicles, radar, cameras etc.) has created a need for general methods by which data can be shared among agencies and users who own disparate computer systems. We present a methodology that demonstrates that it is possible to create, encode...

We present an algorithm that estimates position using the Global Positioning System (GPS) C/A code measurements. We include an approximation for the covariance of the position estimate

This paper presents to a performance quantification methodology for browser applications that operate in a distributed computing environment and are used in a nondeterministic way. It asserts that usability is intimately tied to response time, and that a single metric to quantify response time can be developed using probabilistic arguments. This me...

This paper presents an overview of data fusion issues in a regional architecture setting to support a major operational test. It describes an Intelligent Transportation Society (ITS) regional architecture that will be used to implement data acquisition and data fusion in the Seattle Wide Area Information for Traveler (SWIFT) project

This paper presents an application of microscopic traffic modeling to perform real time highway traffic simulation and prediction. The simulation uses inductance loop data as model input and predicts the downstream traffic based on a microscopic model. The preliminary results show high cross-correlation between the prediction and the real data

This paper presents a performance metric which uses a single number to characterize the response time for a non-deterministic client-server application operating over the Internet. When applied to a Macintosh-based distance learning application called the Digital Anatomist Browser, the metric allowed us to observe that "A typical student doing a ty...

This paper demonstrates the viability of using cross-correlation techniques with inductance loop data to measure the propagation time of traffic. The propagation time between loops separated by 0.5 miles is measured by using time-average activation counts ("volume") from inductance loops. The resulting time delay is used to estimate the mean speed....

Structural information in medicine is information about the physical body. Recent advances in medical imaging and biotechnology have greatly increased the amount and importance of structural information, and advances in networking envisioned by the High Performance Computing and Communication Initiative (HPCC) will allow this kind of information to...

A parameterization of in-core and ex-vessel signals is presented. This set of parameters can be used to quantify the state of the vibrating core internal components in an operating commercial PWR. Coordinated in-core and ex-vessel noise measurements in an operating PWR are the basis upon which the parameters are estimated.

Simultaneous in-core/ex-core neutron noise measurements are investigated. A signal decomposition scheme is proposed for the ex-core signals. Partial spectral estimates are constructed from the in-core signals. Frequency bands that differentiate modified/baffle jet excited assemblies from ‘normal’ are predicted using a clustering algorithm. A simple...

A procedure is introduced for characterizing one dimensional, two phase flow in terms of three properties; propagation, structure, and dynamics. It is shown that all of these properties can be measured by analyzing the response of the reactor neutron field to a two phase flow perturbation. Therefore, a nuclear reactor can be regarded as a two phase...

The neutron noise induced by an air-water loop located in a nuclear reactor is investigated. A simple model of the neutron noise is developed using phenomenological arguments. The model is verified by comparison to experimental results, and three-dimensional, two-energy group diffusion calculations. The aim of the work is to provide the theoretical...

Considerable activity has been devoted in recent years to the use of neutron noise for investigation of problems in pressurized-water reactors (PWRs). The investigators have found that neutron noise provides an effective way to monitor reactor internal vibrations such as vertical and lateral core motion; core support barrel and thermal shield shell...

This project has accomplished three significant tasks. First, a state-of-the-art literature review has provided an organizational framework for categorizing the various data fusion projects that have been conducted to date. A popular typology was discussed which situates data fusion technologies in one of three levels, depending on the degree to wh...

In this paper we describe the usage of a transit vehicle information system that delivers estimated departure times for a large transit fleet by way of internet-enabled mobile devices. While a number of experimental and commercial products are beginning to offer such a service this paper reports the actual usage by patrons of a large transit fleet....

The characterizatoin of two-phase flow in a nuclear reactor is of significance for both operational and safety reasons. This study reports on the exploration of flow-regime characterization by using measurements of the neutron-flux fluctuations induced by the two-phase flow passing through a nuclear-reactor core. It is shown that many significant p...

16. ABSTRACT In this report, we present the use of a generalize prediction algorithm with schedule and vehicle position data from the Tri-Met transit system. We demonstrate the viability of using a general framework, originally developed for use in King County, Washington, to create accurate arrival/departure predictions for the Portland Metro area...

Seattle Smart Traveler (SST) is a world wide web (WWW) application designed to test the concept of "dynamic" rideshare matching. SST collects spatial and temporal trip information using a series of WWW pages, performs a match using SQL specifications to a database engine, and supports both the standard phone-based contact methodology as well as two...

Abstract Image processing has been applied to traffic analysis in recent years, with different goals. In this report, a new approach is presented for extracting vehicular speed information, given a sequence of real-time traffic images. We extract moving edges and process the resulting edge information to obtain quantitative geometric measurements o...

The use of a nuclear reactor as a two phase flow instrument is demonstrated. The basic response functions relating significant two phase flow properties to fluctuations of the neutron density are presented. Methods of treating the data to extract the properties of two phase flow fluctuations are discussed. A typical measurement result is presented....

Thesis (M.S.E.(Nuclear))--University of Washington, 1982. Includes bibliographical references.