scholarly journals Point-Process modeling of Secondary Crashes

2021 ◽  
Author(s):  
Samarth Motagi ◽  
Sirish Namilae ◽  
Audrey Gbaguidi ◽  
Scott Parr ◽  
Dahai Liu
Keyword(s):  
Point Process ◽  
Rate Function ◽  
Model Parameters ◽  
Department Of Transportation ◽  
Background Rate ◽  
Traffic Incident ◽  
Florida Department ◽  
Stationary Function ◽  
Secondary Crashes ◽  
Events Data

Abstract Secondary crashes or crashes that occur in the wake of a preceding or primary crash are among the most critical incidents occurring on highways, due to the exceptional danger they present to the first responders and victims of the primary crash. In this work, we developed a self-exciting temporal point process to analyze crash events data and classify it into primary and secondary crashes. Our model uses a self-exciting function to describe secondary crashes while primary crashes are modeled using a background rate function. We fit the model to crash incidents data from the Florida Department of Transportation, on Interstate-4 (I-4) highway for the years 2015-2017, to determine the model parameters. These are used to estimate the probability that a given crash is secondary crash and to find queue times. To represent the periodically varying traffic levels and crash incidents, we model the background rate, as a stationary function, a sinusoidal non-stationary function, and a piecewise non-stationary function. We show that the sinusoidal non-stationary background rate fits the traffic data better and replicates the daily and weekly peaks in crash events due to traffic rush hours. Secondary crashes are found to account for up to 15.09% of the traffic incident, depending on the city on the I4 Highway.

scholarly journals Theory and Applications of the Unit Gamma/Gompertz Distribution

Mathematics ◽  
2021 ◽  
Vol 9 (16) ◽  
pp. 1850
Author(s):  
Rashad A. R. Bantan ◽  
Farrukh Jamal ◽  
Christophe Chesneau ◽  
Mohammed Elgarhy
Keyword(s):  
Stochastic Ordering ◽  
Real Data ◽  
Rate Function ◽  
The Other ◽  
Likelihood Method ◽  
Model Parameters ◽  
Data Sets ◽  
Gompertz Distribution ◽  
Probability And Statistics ◽  
Analytical Behavior

Unit distributions are commonly used in probability and statistics to describe useful quantities with values between 0 and 1, such as proportions, probabilities, and percentages. Some unit distributions are defined in a natural analytical manner, and the others are derived through the transformation of an existing distribution defined in a greater domain. In this article, we introduce the unit gamma/Gompertz distribution, founded on the inverse-exponential scheme and the gamma/Gompertz distribution. The gamma/Gompertz distribution is known to be a very flexible three-parameter lifetime distribution, and we aim to transpose this flexibility to the unit interval. First, we check this aspect with the analytical behavior of the primary functions. It is shown that the probability density function can be increasing, decreasing, “increasing-decreasing” and “decreasing-increasing”, with pliant asymmetric properties. On the other hand, the hazard rate function has monotonically increasing, decreasing, or constant shapes. We complete the theoretical part with some propositions on stochastic ordering, moments, quantiles, and the reliability coefficient. Practically, to estimate the model parameters from unit data, the maximum likelihood method is used. We present some simulation results to evaluate this method. Two applications using real data sets, one on trade shares and the other on flood levels, demonstrate the importance of the new model when compared to other unit models.

Collection, Analysis, and Reporting of Kentucky Traffic Incident Management Performance

2021 ◽  
pp. 036119812110010
Author(s):  
Xu Zhang ◽  
Reginald R. Souleyrette ◽  
Eric Green ◽  
Teng Wang ◽  
Mei Chen ◽  
...  
Keyword(s):  
Motor Vehicle ◽  
Management Strategies ◽  
Incident Management ◽  
Vehicle Crashes ◽  
Clearance Time ◽  
Emergency Responders ◽  
Traffic Incident ◽  
Choropleth Maps ◽  
Traffic Incident Management ◽  
Secondary Crashes

Traffic incidents remain all too common. They negatively affect the safety of the traveling public and emergency responders and cause significant traffic delays. Congestion associated with incidents can instigate secondary crashes, exacerbating safety risks and economic costs. Traffic incident management (TIM) provides an effective approach for managing highway incidents and reducing their occurrence and impacts. The paper discusses the establishment and methods of calculation for five TIM performance measures that are used by the Kentucky Transportation Cabinet (KYTC) to improve incident response. The measures are: roadway clearance time, incident clearance time, secondary crashes, first responder vehicle crashes, and commercial motor vehicle crashes. Ongoing tracking and analysis of these metrics aid the KYTC in its efforts to comprehensively evaluate its TIM program and make continuous improvements. As part of this effort, a fully interactive TIM dashboard was developed using the Microsoft Power BI platform. Dashboard users can apply various spatial and temporal filters to identify trends at the state, district, county, and agency level. The dashboard also supports dynamic visualizations such as time-series plots and choropleth maps. With the TIM dashboard in place, KYTC personnel, as well as staff at other transportation agencies, can identify the strengths and weaknesses of their incident management strategies and revise practices accordingly.

scholarly journals Bayesian and Classical Inference under Type-II Censored Samples of the Extended Inverse Gompertz Distribution with Engineering Applications

Entropy ◽  
2021 ◽  
Vol 23 (12) ◽  
pp. 1578
Author(s):  
Ahmed Elshahhat ◽  
Hassan M. Aljohani ◽  
Ahmed Z. Afify
Keyword(s):  
Real Life ◽  
Rate Function ◽  
Parameter Distribution ◽  
Model Parameters ◽  
Alpha Power ◽  
Type Ii ◽  
Failure Rate Function ◽  
Censored Samples ◽  
Inverse Gamma ◽  
Bathtub Shape

In this article, we introduce a new three-parameter distribution called the extended inverse-Gompertz (EIGo) distribution. The implementation of three parameters provides a good reconstruction for some applications. The EIGo distribution can be seen as an extension of the inverted exponential, inverse Gompertz, and generalized inverted exponential distributions. Its failure rate function has an upside-down bathtub shape. Various statistical and reliability properties of the EIGo distribution are discussed. The model parameters are estimated by the maximum-likelihood and Bayesian methods under Type-II censored samples, where the parameters are explained using gamma priors. The performance of the proposed approaches is examined using simulation results. Finally, two real-life engineering data sets are analyzed to illustrate the applicability of the EIGo distribution, showing that it provides better fits than competing inverted models such as inverse-Gompertz, inverse-Weibull, inverse-gamma, generalized inverse-Weibull, exponentiated inverted-Weibull, generalized inverted half-logistic, inverted-Kumaraswamy, inverted Nadarajah–Haghighi, and alpha-power inverse-Weibull distributions.

Development and Implementation of a Pavement Marking Management System in Florida

2018 ◽  
Vol 2672 (12) ◽  
pp. 209-219
Author(s):  
Bouzid Choubane ◽  
Joshua Sevearance ◽  
Charles Holzschuher ◽  
James Fletcher ◽  
Chieh (Ross) Wang
Keyword(s):  
Management System ◽  
Handheld Devices ◽  
Department Of Transportation ◽  
Pavement Markings ◽  
Lighting Conditions ◽  
Florida Department ◽  
Roadway Safety ◽  
Application Techniques ◽  
Effective Use ◽  
Pavement Marking

The visibility of pavement markings is an important aspect of a safe transportation system as the markings convey vital roadway warnings and guidance information to the traveling public. Therefore, it is beneficial to maintain acceptable visibility levels of markings on pavements under all weather and lighting conditions. To ensure the intended in-service visibility level is adequately maintained, the reflectivity must be monitored and quantified accordingly. Historically, visibility or retroreflectivity of in-service pavement markings has been measured with handheld devices and visual inspections. However, visual surveys are considered subjective and the handheld measurements are tedious and potentially hazardous. Consequently, the Florida Department of Transportation (FDOT) has focused on the use of a non-contact technology capable of assessing pavement markings continuously at highway speeds with improved safety and efficiency. The use of mobile technology for measuring reflectivity has allowed FDOT to develop and, subsequently, implement a Pavement Marking Management System (PMMS) to improve the safety and nighttime visibility of its roadways. Implementation of such a system provides an efficient and less subjective methodology to identify conditions that are detrimental to roadway safety, and strategize mitigating solutions including the selection of appropriate materials and application techniques. The system will ultimately result in an effective use of state funds while ensuring the safety of the traveling public. This paper presents a description of the Florida Pavement Markings Management System and its subsequent implementation including FDOT’s effort to ensure the quality, consistency, repeatability, and accessibility of statewide pavement marking retroreflectivity data.

scholarly journals A New Flexible Bathtub-Shaped Modification of the Weibull Model: Properties and Applications

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Qinghu Liao ◽  
Zubair Ahmad ◽  
Eisa Mahmoudi ◽  
G. G. Hamedani
Keyword(s):  
Weibull Distribution ◽  
Hazard Rate ◽  
Likelihood Estimation ◽  
Estimation Procedure ◽  
Weibull Model ◽  
Rate Function ◽  
Model Parameters ◽  
Hazard Functions ◽  
Practical Applications ◽  
Nonnested Models

Many studies have suggested the modifications and generalizations of the Weibull distribution to model the nonmonotone hazards. In this paper, we combine the logarithms of two cumulative hazard rate functions and propose a new modified form of the Weibull distribution. The newly proposed distribution may be called a new flexible extended Weibull distribution. Corresponding hazard rate function of the proposed distribution shows flexible (monotone and nonmonotone) shapes. Three different characterizations along with some mathematical properties are provided. We also consider the maximum likelihood estimation procedure to estimate the model parameters. For the illustrative purposes, two real applications from reliability engineering with bathtub-shaped hazard functions are analyzed. The practical applications show that the proposed model provides better fits than the other nonnested models.

scholarly journals Slashed Lomax Distribution and Regression Model

Symmetry ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 1877
Author(s):  
Huihui Li ◽  
Weizhong Tian
Keyword(s):  
Regression Model ◽  
Hazard Rate ◽  
Rate Function ◽  
Model Parameters ◽  
Asymmetric Distribution ◽  
Hazard Rate Function ◽  
Simulation Studies ◽  
Ecm Algorithm ◽  
Lomax Distribution ◽  
Skewness And Kurtosis

In this article, the slashed Lomax distribution is introduced, which is an asymmetric distribution and can be used for fitting thick-tailed datasets. Various properties are explored, such as the density function, hazard rate function, Renyi entropy, r-th moments, and the coefficients of the skewness and kurtosis. Some useful characterizations of this distribution are obtained. Furthermore, we study a slashed Lomax regression model and the expectation conditional maximization (ECM) algorithm to estimate the model parameters. Simulation studies are conducted to evaluate the performances of the proposed method. Finally, two sets of data are applied to verify the importance of the slashed Lomax distribution.

Intersection Level of Service for the Bicycle Through Movement

2003 ◽  
Vol 1828 (1) ◽  
pp. 101-106 ◽  
Author(s):  
Bruce W. Landis ◽  
Venkat R. Vattikuti ◽  
Russell M. Ottenberg ◽  
Theodore A. Petritsch ◽  
Martin Guttenplan ◽  
...  
Keyword(s):  
Transportation Network ◽  
Pearson Correlation ◽  
Geographic Origin ◽  
Level Of Service ◽  
Total Width ◽  
Department Of Transportation ◽  
Service Model ◽  
Florida Department ◽  
Bicycle Level Of Service ◽  
Time Perceptions

The Florida Department of Transportation (DOT) has initiated multi-modal level-of-service (LOS) methodologies, including that for the bicycle travel mode. It has already adopted a bicycle LOS methodology for the roadway segment portion of the transportation network, the Bicycle Level of Service Model. Florida DOT’s ultimate goal is to develop corridor- and facilities-level LOS methodologies. Toward that goal, Florida DOT sponsored research to develop the first part of an intersection bicycle LOS methodology, the Intersection LOS for the bicycle through movement. This Intersection LOS for the bicycle through movement would provide a measure of the level of safety and comfort experienced by bicyclists riding through an intersection. The Intersection LOS model for the bicycle through movement is based on Pearson correlation analyses and stepwise regression modeling of approximately 1,000 combined real-time perceptions from bicyclists traveling a course through a typical U.S. metropolitan area’s signalized intersections. The study’s participants represented a cross section of age, gender, and geographic origin of the population of cyclists. Although further hypothesis testing is being conducted, the resulting general model for the Intersection LOS for the bicycle through movement is highly reliable, has a high correlation coefficient ( R2 = 0.83) with the average observations, and is transferable to the vast majority of U.S. metropolitan areas. The study reveals that roadway traffic volume, total width of the outside through lane, and the intersection (cross street) crossing distance are primary factors in the Intersection LOS for the bicycle through movement.

Repeatability and Reproducibility of Mobile Retroreflectivity Units for Measurement of Pavement Markings

2013 ◽  
Vol 2337 (1) ◽  
pp. 74-82 ◽  
Author(s):  
Bouzid Choubane ◽  
Joshua Sevearance ◽  
Hyung Suk Lee ◽  
Patrick Upshaw ◽  
James Fletcher
Keyword(s):  
Handheld Devices ◽  
Department Of Transportation ◽  
Safety Hazards ◽  
Handheld Device ◽  
Pavement Markings ◽  
Florida Department ◽  
Reference Device ◽  
Efficient Alternative ◽  
Repeatability And Reproducibility ◽  
Pavement Marking

The Florida Department of Transportation has historically used a combination of handheld devices and visual surveys to evaluate the retroreflectivity of pavement markings. However, visual surveys have the inherent limitations of operator bias, while the use of a handheld device is slow and labor intensive and presents safety hazards. Many highway agencies have recognized that a mobile retroreflectivity unit (MRU) may be a safer and more efficient alternative to the handheld retroreflectometers. Because the measurement process relies on the operator-driven instrument, a level of uncertainty is always a concern in evaluating pavement markings with the MRU. This research was aimed at assessing the precision and bias of the MRU while using the handheld retroreflectometer as a reference device. Ten 1.0-mi-long field sites were selected to include various pavement surface types and pavement marking materials (paints and thermoplastics). The results indicated that, when compared with the handheld retroreflectometers, the MRU demonstrated no statistical differences or bias at a 95% confidence level for the retroreflectivity values ranging between 200 and 800 mcd/m2/lux. In addition, it was determined that the retroreflectivity values from two properly conducted tests using a single MRU on the same pavement marking should not differ by more than 7.8%, and when different MRUs were used on the same pavement marking, the retroreflectivity values should not differ by more than 13.3%. This paper presents a description of the testing program, the data collection effort, and the subsequent analyses and findings.

Superpave Field Implementation: Florida’s Early Experience

1998 ◽  
Vol 1609 (1) ◽  
pp. 51-60 ◽  
Author(s):  
James A. Musselman ◽  
Bouzid Choubane ◽  
Gale C. Page ◽  
Patrick B. Upshaw
Keyword(s):  
Asphalt Pavement ◽  
Early Experience ◽  
Field Application ◽  
Pavement Performance ◽  
Department Of Transportation ◽  
Concerted Effort ◽  
The Past ◽  
Early Experiences ◽  
Florida Department ◽  
Current Loading

Over the past 10 to 15 years, Interstate pavements in northern Florida have experienced a significant number of failures, primarily due to rutting. It was believed that the present fine-graded, 50-blow Marshall-designed mixes were inadequate to withstand current loading conditions. The newly developed Superpave system represented an opportunity to address several of Florida’s asphalt pavement problems. Thus, the Florida Department of Transportation made a concerted effort to implement Superpave technology in 1996. During this period, eight projects were changed from the traditional Marshall mix designs to Superpave. Although the new procedure offers potential for improved pavement performance, there has been very little experience nationally with its field application. Florida’s early experiences with the field implementation of Superpave are documented.

Deployment and Testing of Optimized Autonomous and Connected Vehicle Trajectories at a Closed-Course Signalized Intersection

2018 ◽  
Vol 2672 (19) ◽  
pp. 45-54 ◽  
Author(s):  
Aschkan Omidvar ◽  
Mahmoud Pourmehrab ◽  
Patrick Emami ◽  
Rebecca Kiriazes ◽  
John C. Esposito ◽  
...  
Keyword(s):  
Traffic Control ◽  
Traffic Engineering ◽  
Signal Control ◽  
Connected Vehicle ◽  
Department Of Transportation ◽  
Vehicle Trajectories ◽  
Florida Department ◽  
Traffic Control System ◽  
Demand Condition ◽  
Field Deployment

In this paper, we discuss the deployment and testing of an intelligent real-time isolated intersection traffic control system (IICS), designed to optimize simultaneously signal control and automated vehicle (AV) and connected vehicle (CV) trajectories for low demand condition. The work described here is part of an ongoing larger project (funded by the National Science Foundation and the Florida Department of Transportation, FDOT) to develop, test, and deploy the IICS. The focus of this paper is on the deployment and testing of the algorithm at the Traffic Engineering and Research Laboratory (TERL), FDOT’s closed-course facility. The algorithm (described in more detail elsewhere) optimizes signal control and provides optimal AV and CV trajectories at isolated intersections. The algorithm is designed to handle AV, CV, and conventional vehicles in a mixed traffic and low demand condition. The paper provides an overview of the IICS framework, discusses the development and testing of the necessary software and hardware, and presents the scenarios tested at the TERL. The results from the field test confirm the feasibility of the IICS, and will be used to enhance it for future testing and ultimately for field deployment and in high demand condition.

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