DSpace Repository :: Browsing by Author "Jones, Steven L."

Browsing by Author "Jones, Steven L."

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Accessibility and university populations: local effects on non-motorized transportation in the Tuscaloosa-Northport area
(University of Alabama Libraries, 2012) Lundberg, Benjamin; Weber, Joe; University of Alabama Tuscaloosa
This research examined the local bicycle and pedestrian networks through Geographic Information Systems (GIS) and survey data, using the Tuscaloosa and Northport, Alabama, area as a case study. The local non-motorized travel networks were analyzed in GIS to measure the overall network connectivity and accessibility. Results of the measures of network connectivity and modeling of accessibility indicated that areas within one mile of the UA's campus have the highest levels of bicycle and pedestrian network connectivity and accessibility. As a travel distance increases from UA, connectivity and accessibility for the bicycle and pedestrian networks decreases. An on-line survey was administered to the University of Alabama (UA) students and employees, and the results of the survey were used to formulate an understanding of how UA's population views non-motorized travel and the respective networks. Survey results show that individuals within the sample population use non-motorized travel methods to commute to UA but their use is significantly lower than automobile use. In addition, the survey data was considered alongside evaluations of network connectivity and accessibility, thus providing a powerful tool for studying the local bicycle and pedestrian travel networks.
Analyzing crash frequency and severity data using novel techniques
(University of Alabama Libraries, 2014) Mehta, Gaurav Satish; Jones, Steven L.; Lou, Yingyan; University of Alabama Tuscaloosa
Providing safe travel from one point to another is the main objective of any public transportation agency. The recent publication of the Highway Safety Manual (HSM) has resulted in an increasing emphasis on the safety performance of specific roadway facilities. The HSM provides tools such as crash prediction models that can be used to make informed decisions. The manual is a good starting point for transportation agencies interested in improving roadway safety in their states. However, the models published in the manual need calibration to account for the local driver behavior and jurisdictional changes. The method provided in the HSM for calibrating crash prediction models is not scientific and has been proved inefficient by several studies. To overcome this limitation this study proposes two alternatives. Firstly, a new method is proposed for calibrating the crash prediction models using negative binomial regression. Secondly, this study investigates new forms of state-specific Safety Performance Function SPFs using negative binomial techniques. The HSM's 1st edition provides a multiplier applied to the univariate crash prediction models to estimate the expected number of crashes for different crash severities. It does not consider the distinct effect unobserved heterogeneity might have on crash severities. To address this limitation, this study developed a multivariate extension of the Conway Maxwell Poisson distribution for predicting crashes. This study gives the statistical properties and the parameter estimation algorithm for the distribution. The last part of this dissertation extends the use of Highway Safety Manual by developing a multivariate crash prediction model for the bridge section of the roads. The study then compares the performance of the newly proposed multivariate Conway Maxwell Poisson (MVCMP) model with the multivariate Poisson Lognormal, univariate Conway Maxwell Poisson (UCMP) and univariate Poisson Lognormal model for different crash severities. This example will help transportation researchers in applying the model correctly.
Assessing the role of bikesharing in transit-oriented development: a case study of Birmingham
(University of Alabama Libraries, 2016) Glass, Caroline Day; Appiah-Opoku, Seth; University of Alabama Tuscaloosa
Transit-oriented development (TOD) is a community development strategy that has increasingly gained exposure in urban areas across the United States as a method for reducing sprawl and increasing community vitality. Specifically, bikesharing is seen to play a major role in the success of transit-oriented development across urban communities as it increases travel possibilities, encourages public transit connections, and provides opportunities for recreation. This research employed a case study of Zyp BikeShare, a point-to-point bike rental program that began in Birmingham, Alabama, in 2015. Here, we analyzed the bikesharing program in terms of implementation and development, user catchment, transit paths, and usage trends. In doing so, we were able to create a methodology for analyzing specific bikeshare programs. Similar methodology can be applied to other bikesharing programs as the transit-oriented development technique continues to grow and develop in American cities.
Assessing the weekend accessibility of Rutgers University libraries
(University of Alabama Libraries, 2015) Hoffman, Amanda Jane; Weber, Joe; University of Alabama Tuscaloosa
Rutgers University- New Brunswick is a public four-year institution located within the limits of New Brunswick and Piscataway, New Jersey. Separated into four sub-campuses, Rutgers University – New Brunswick has developed an intricate campus transit system. Rutgers is one of many institutions who have sought to become more sustainable entities, in order to continue to provide exceptional services to students for the foreseeable future. In order to do so, universities are beginning to look towards alternative methods of transportation for their students to limit the use of private vehicles. This thesis research highlights the weekend accessibility of the four major campus libraries on the New Brunswick campus of Rutgers, comparing the usage of the campus transit system and one’s private vehicle. Using the potential interaction model of accessibility, this research measures the accessibility of each sub-campus to the library on the other 3 sub-campuses and each library to students coming from the other sub-campuses. The results of this research show which campus library is the most accessible to students from the other sub-campuses and which sub-campus is the most accessible to the 3 other libraries. This research also highlights the accessibility gap between students who take the campus transit system and those who make use of their private vehicle.
Bridge weigh-in-motion deployment opportunities in Alabama
(University of Alabama Libraries, 2011) Brown, Alan James; Jones, Steven L.; Richardson, James A.; University of Alabama Tuscaloosa
Overweight vehicle enforcement is a continuous problem for all state Departments of Transportation. Various technologies are in use across the US to aid in the enforcement of vehicle weight limits. However, to date, no technology has been shown to be a definitive solution. The various technologies currently available were researched and the pros and cons of each highlighted. Focus was placed on Bridge Weigh-in-Motion (B-WIM) and an extensive literature review has been conducted following all developments in the field of B-WIM since 1979. The advantages of B-WIM include its ease of installation, portability and potential for high accuracy vehicle weight measurements. Accuracy however is site specific, which makes the selection of a bridge an extremely important element in the success of a B-WIM installation. A bridge selection tool prototype was developed using ArcGIS. The tool was designed to select bridges with the physical characteristics associated with achieving high B-WIM weight measurement accuracies. Daily truck volumes and current Weigh-in-Motion (WIM) sites were also included in the tool to allow for an effective choice of route for installation. As the systems use cellular data signals to transfer data to the weigh crew during the pre-selection process, cell service maps were also included in the tool. The prototype showed that such a tool is feasible and should be beneficial for ALDOT. ALDOT owns two B-WIM systems which it intends to use for overweight vehicle enforcement. An accuracy test of the system was conducted. A bridge in West Alabama was selected for installation. Calibration was conducted and random vehicles were statically weighed to verify the accuracy of the system. A gross vehicle weight accuracy of B (10) was obtained which is more than sufficient for pre-selection of potentially overweight vehicles. Alternative sensor locations and orientations were also investigated and signals were compared. It was found that longitudinal axle detectors located close to the bridge supports provided the cleanest and most distinct signals at the test location. Weighing sensors located at the mid-span provided the best signals for weighing trucks.
Conditional cell transmission model for two-way arterials in oversaturated conditions
(University of Alabama Libraries, 2010) Wang, Ping; Jones, Steven L.; University of Alabama Tuscaloosa
In 2007, congestion caused urban Americans to travel 4.2 billion hours more and to purchase an extra 2.8 billion gallons of fuel for a congestion cost of $87.2 billion - an increase of more than 50% over the previous decade. Urban arterials operating in oversaturated conditions are now very common and are expected to become even more prevalent. As a result, there is an urgent need to explicitly address oversaturation. Simulation of oversaturation plays an important role in addressing it. However, the previous research, including existing traffic simulation software and theoretical approaches, take full account of traffic flow on two way arterials in oversaturated conditions. Therefore, improvements of existing traffic flow model simulation techniques are necessary to adequate study such fully oversaturated arterials. The objective of this research is to develop a novel feature for traffic flow models, to simulate when traffic queues on two way arterials periodically extend until then block an upstream signal in oversaturated conditions. Such a model should be capable of delineating the dynamic of traffic flow created by the merging and diverging activities on two way arterials. In additional, it should have the capability of describing blockages, spillback and shock wave phenomena along the oversaturated arterials. The Cell Transmission model (CTM) is used in the dissertation, because it can accommodate all traffic conditions from light condition to oversaturated condition. However, it has limitations and has only recently been extended from one way two way arterials. Two way arterials have more diverge and merge activities at intersections, which make the coding of CTM more complex and time-consuming. Second, a noticeable inaccuracy in prior CTM research is the failure to simulate the blockages at intersections. They typically estimate the delay occurring on segments and ignore the delay occurring at intersections. These limitations affect CTM's accuracy and limit its use. To enhance CTM, a conditional cell transmission model (CCTM) is developed with two improvements. First, CTM is expanded for two-way arterials by taking account of all diverge and merge activities at intersections. Second, a conditional cell is added to simulate periodic spillback and blockages at an intersection. The cell exists conditionally, depending on whether or not there is a spillback at an intersection. In other words, if spillback happens, the conditional cell exists and stores the vehicles which spill back into the intersection; if there is no spillback, the conditional cell will not exist. In CCTM, users may input the probability of a conditional cell (drivers breaking the driving rule) and probability of occurrence of useful location of a gap to match the characteristics of local drivers' behavior. This is a unique contribution of CCTM. The CCTM traffic flow simulation was initially developed using evolutions of small model of six cell mode. It included (a segment cell, a diverge cell, a cell in front of an intersection, a cell in a left turn lane, a cell in the minor street and a conditional cell). They were loaded with light duty traffic, moderate duty traffic and heavy duty traffic respectively. To test the overall performance of CCTM, a series of experiments are designed and performed for a multilane, two-way, three-signal sample network. Experiments were conducted to give sensitivity analyses to four user-defined parameters including traffic demand, traffic signal timing, possibility of occurrence of a useful gap and possibility of a conditional cell. The results demonstrate that CCTM can accommodate various traffic demands and CCTM's accurate representation of traffic flow. Finally, to validate CCTM, it is compared with HCS (Highway Capacity Software 2000). Three scenarios of traffic demand are inputted into HCS and the results of travel speeds are compared with those of CCTM. The consistency between HCS 2000 and CCTM shows that CCTM is a reliable methodology of modeling traffic flow in oversaturated condition.
Development of crash modification factors for bridge rail improvements
(University of Alabama Libraries, 2015) Fields, Robert Tyler; Jones, Steven L.; University of Alabama Tuscaloosa
Bridge components such as bridge railings are safety features designed to protect drivers. The guidelines for those safety features have recently been updated to accommodate for the increase in vehicle size. One method to bring non-conforming bridges up to current standards is retrofitting. The objective of this research is to determine the safety effectiveness of retrofitted bridges that have been updated to current standards. Bridge data and bridge related crash data from historical data for Alabama were collected. The data was cleaned and processed in a geographic information system. The remaining data was used in the development of Safety Performance Functions (SPFs) and Crash Modification Factors (CMFs). The SPFs used in this study were developed to predict crash frequency and severity in future years based on roadway and geometric characteristics. The SPFs for general crashes were developed using Negative Binomial. The SPFs for severity of single vehicle crashes were developed using both Negative Binomial and Conway-Maxwell-Poisson. The SPFs used in this study were developed in a connected study and used in this study as part of the CMF development. After obtaining the various prediction models for general crashes and for single vehicle severity crashes, the research utilized the information obtained from them in the development of the CMFs. This research employed the empirical Bayes (EB) before-after approach to develop the CMFs. The CMFs were a measure of effectiveness for retrofitting bridge railings to meet current standards. CMFs were determined for both the general crash and for severity of single vehicle crashes. The findings of this research were that retrofitting bridges to conform to the current standards results in a reduction in crashes and a reduction in the severity of crashes. The findings of this research can aid in the decision making process involving bridge railing improvements
Evaluating Transportation Network Mobility and Enhancing Traffic Signal Operations Performance Using Probe Data and Connected Vehicle Technology
(University of Alabama Libraries, 2021) Talukder, MD Abu Sufian; Hainen, Alexander M.; University of Alabama Tuscaloosa
High-quality, reliable, and robust data is key to better understanding performance and improvement needs for transportation infrastructure. Predominantly, transportation systems performance has been evaluated using infrastructure-based data, which is often limited by high costs, small sample size, and potential inaccuracy. With recent advancements in technology, previously unobtainable large high-fidelity data, such as probe data and connected vehicle (CV) data, can now be utilized to address many challenges related to transportation systems. This dissertation investigates various research and practical oriented applications for such emerging transportation data sources. The first part of this dissertation develops a novel methodology for characterizing mobility of transportation networks. Using probe vehicle travel times, a route-based travel time reliability metric is proposed for assessing and comparing transportation system’s performance from one geographic area to another. The second part of this dissertation uses CV-technology to develop methodology for improving operational efficiency at a signalized intersection. Two innovative traffic signal control algorithms are established to demonstrate real-time delay optimization for both connected and non-connected vehicles. The third part of this dissertation extends the use of CV-technology to facilitate prioritized freight movement in a signalized corridor. An estimated time of arrival (ETA)-based priority logic is developed, and the proposed priority system is deployed along US-82 in Northport and Tuscaloosa, Alabama. Finally, this dissertation explores the application of emerging transportation data collection technologies to characterize and evaluate transportation systems performance. The techniques presented in this dissertation will be helpful to transportation agencies, planners, and practitioners to assess existing performance and need for future transportation infrastructure.
Evaluation of the Alabama ticketing aggressive cars and trucks selective enforcement program
(University of Alabama Libraries, 2016) Dye, Daniel Christopher; Jones, Steven L.; University of Alabama Tuscaloosa
Crashes involving passenger vehicles and large commercial motor vehicles have a greater potential for being severe. A summary of crash statistics involving these types of crashes is presented and the problem is examined. Selective Traffic Enforcement Programs attempt to curb particular causes of crashes by using media campaigns and high-visibility enforcement. A background on the Click It or Ticket and Ticketing Aggressive Cars and Trucks programs is given. The focus of this research was to evaluate the effectiveness of the Alabama implementation of the Ticketing Aggressive Cars and Trucks program from January 2010-August 2015. Data was collected from various sources to evaluate the program. This included crash data as well as officer reports from each program shift completed. The crash data was mapped and evaluated for hotspots. Officer reports were evaluated for how many hours were worked, where officers focused their enforcement, how many and what types of citations were written, and the effects of varying levels of enforcement on crash rates. Analysis of Variation and Fisher’s Least Significant Difference post-hoc tests were performed to evaluate this data. In addition to the above sources of data, video observation of traffic events were also recorded and analyzed for effects of the program. Evaluators scored each car-truck interaction as safe, or unsafe, with unsafe actions including changing lanes too close to the front of a truck, remaining in a truck’s blind spot for an unsafe amount of time, or following too close to another vehicle. The results of the analysis showed that the program was effective. Officers successfully focused their enforcement on areas with the highest density of the targeted crashes. Medium levels of enforcement decreased crashes versus low levels (506 versus 555 crashes, significant at p-value 0.003.) High and medium enforcement was shown to reduce the number of crashes compared with low levels of enforcement (509 versus 555 crashes, significant at p-value 0.004.) Observational data was not able to demonstrate any noticeable effects of the program. Recommendations to improve the program include increasing public awareness of the program, increasing officer contacts per hour, concentrating officer enforcement over designated periods and designating months as enforcement or non-enforcement months for purposes of evaluation. Ways to improve the evaluation of the program included the introduction of a control corridor and automation of observational analysis.
Exploratory applications of epidemiological methods in transport safety and mobility
(University of Alabama Libraries, 2017) Adanu, Emmanuel Kofi; Jones, Steven L.; University of Alabama Tuscaloosa
Evident similarities and links between the outcomes of traffic crashes and stranded (or constrained) mobility have been identified and are reported in this research. Generally, a high level of travel activities is an indicator of high crash exposure. However, studies have shown that the highest rates of traffic fatalities occur in low- and middle-income regions, where many citizens experience relatively low levels of motorized travel. This ironic observation reveals serious challenges facing transport mobility systems in the less privileged regions of the world. Studies on traffic crashes and mobility constraints also reveal that they both have individual and regional variations in their occurrence, effects, and severities. Consequently, the outcomes of traffic crashes and constrained mobility are serious public health concerns worldwide. As public health problems, their study is analogous to the study of diseases and other injuries and thus, suitable for the application of epidemiological techniques. This dissertation therefore explores the use of epidemiological techniques to analyze traffic crashes and mobility/accessibility constraints from a human-centered perspective. The dissertation therefore consists of two major focus areas. The first part of the study applies widely used epidemiology/public health – based statistical tools to analyze traffic crashes with the aim of gaining better understanding of the human-centered causes and factors that influence these causes, and how these ultimately affect the severity of crashes. This part is further divided into two sub-sections. The first sub-section used latent class analysis to identify homogeneous clusters of human-centered crash causal factors and then applied latent class logit and random parameters logit modeling techniques to investigate the effects of these factors on crash outcomes. The second sub-section of the first part of the dissertation applies multilevel regression analysis to understand the effects of driver residential factors on driver behaviors in an attempt to explain the area-based differences in the severity of road crashes across sub-regions. Both studies are necessary to develop potential human-centered mitigations and interventions and for the effective and targeted implementation of those countermeasures. The second part of the study provides an epidemiological framework for addressing mobility/accessibility constraints with a view to diagnosing symptoms, recommending treatment, and even discussing the idea of transmission of constrained mobility among city dwellers. The medical condition, hypomobility, has been used to connote constrained mobility and accessibility for people in urban areas. In transportation and urban studies, hypomobility can result in a diminished ability to engage in economic opportunities and social activities, hence deepening poverty and social exclusion and increasing transport costs, among other negative outcomes. The condition is especially pronounced in poor urban areas in developing countries. The framework proposed in this study is expected to help identify and address barriers to mobility and accessibility in the rapidly growing cities throughout the developing world, with particular applicability to the rapidly developing cities in Sub-Saharan Africa. Ultimately, this dissertation explores the application of epidemiological techniques to two major transportation problems: traffic safety and constrained mobility. The techniques presented in this dissertation provide policy makers, agencies, and transport professionals with tools for evidence-based policies and effective implementation of appropriate countermeasures.
Exploring the potential health and safety issues of artisanal and small-scale gold mining in Ghana; a case study
(University of Alabama Libraries, 2017) McWhorter, William; Appiah-Opoku, Seth; University of Alabama Tuscaloosa
Artisanal and Small-Scale Gold Mining is a way of life for many individuals living in developing countries, especially Africa. This subsistence form of mining provides many households with an income to provide food and shelter for their families. Although done with good intentions, limited financial resources along with the lack of government capacity to properly regulate small-scale gold mining activities leads to hazardous working conditions that can be detrimental to both human health and the environment. By using a case study approach, this paper explores the current mining techniques being used in rural Ghana to identify the health and safety issues associated with small-scale gold mining and policy options to help streamline the mining process. Although the appropriate regulations exist, much of Ghana’s small-scale gold mining sector is pushed to operate informally which through financial shortcuts exposes miners and the surrounding community to health and safety risks. By identifying the issues at hand, we hope to promote more effective policies that streamline the small-scale gold mining process through active local government cooperation while creating a more sustainable environment and safe workplace for future generations.
A feasibility study of a bike share program on the University of Alabama campus
(University of Alabama Libraries, 2019) Oppong, Judith Ntow; Appiah-Opoku, Seth; University of Alabama Tuscaloosa
This thesis sets out to examine how feasible a bike share program will be at the University of Alabama (UA). Three case studies of campus bike sharing programs across the United States are used to show the different bike sharing systems in existence. The advantages of a bike sharing program are highlighted to show how the system can offer alternative transportation to the university campus. The current status of bicycle uses on University of Alabama campus as well as policies put in place are also discussed. The last part of the thesis applies lessons learnt from the case studies and evolution of bike share to a feasibility study for UA campus.
Framework for integrating indigenous and scientific knowledge for transportation planning in developing countries
(University of Alabama Libraries, 2012) Tefe, Moses Kwame; Jones, Steven L.; University of Alabama Tuscaloosa
Conventional transportation planning is developed based on theories that originate from industrialized countries and is based on the rational/comprehensive model, which is an exercise in data manipulation. The basic requirements of the process are the availability of large amounts of good data and analytic capabilities. These are readily available in industrialized countries, but often lacking in developing countries, hence the need to explore other non-traditional methods for project evaluation. This research documents a framework suggested for screening urban transportation projects in developing countries to reflect local issues relevant to sustainability. The framework is based on the integration of indigenous and scientific knowledge to reflect the sustainability of candidate projects. This is achieved through a transactive or dialogical instrumentalism and social learning, to integrate inputs from system users and providers to produce a term defined as the Localized Sustainability Score (LSS). This is a method that readily identifies with the consensus building tradition of local communities in developing countries. The LSS of the projects are then used to produce a relative ranking of potential projects, for use as a decision support for project screening and selection. The proposed method was developed through a case study in Accra, Ghana and the results indicate that the framework adequately represented local sustainable transportation needs, priorities and perceptions. The LSS determined for some selected projects maintained the original relative rankings that were already derived using conventional methods. The LSS also has the added advantage of evaluating projects of different scales.
Freeway Incident Management: Analyzing the Effectiveness of Freeway Service Patrols on Incident Clearance Times
(University of Alabama Libraries, 2021) Islam, Naima; Hainen, Alexander M.; University of Alabama Tuscaloosa
Traffic incidents caused by vehicular crashes, roadway construction, disabled and abandoned vehicles, extreme weather conditions, and planned special events, comprise about half of all traffic congestion. As the duration of traffic incidents increases, it increases the probability of severe congestion, secondary crashes, traveler delay, travel time variability, emissions and fuel consumption, air pollution, economic and social inadequacy, as well as reduces the roadway capacity and the reliability of the whole transportation system. Freeway service patrol (FSP) programs have been considered as an effective Traffic Incident Management (TIM) program for reducing incident duration and thereby minimizing the adverse effects of traffic incidents. The overarching goal of this dissertation is to assess the impact of Alabama Service and Assistant Patrol (ASAP) program based on a unique compiled dataset. The specific objectives are: (1) to merge and match four different datasets, including response data, crash data, traffic volume data and ASAP data; (2) to identify the explanatory variables of incident clearance times with an emphasis on the ASAP coverage area information; (3) to assess duration data using hazard-based duration models with the aim of determining which modeling method best fits the data; and (4) to verify the spatial transferability for the impact of ASAP coverage area. To achieve the research objectives, this dissertation is divided into three parts. The first part describes the Weibull distribution with gamma heterogeneity in identifying the explanatory variables of incident clearance times. The second part compares two advanced econometric modeling methods (random parameters and latent class) in identifying which modeling method best fits the data. The third part employs random parameters modeling method to verify the spatial transferability of the impact of the ASAP program across the state. Ultimately, this dissertation presents a data-driven assessment of the ASAP program in the state. The distinctive contribution of this research is to provide a better understanding of the significant variables that influenced the freeway incident clearance times. The findings of this dissertation are anticipated to assist TIM agencies in formulating and implementing strategic plans to reduce freeway incident clearance times while maximizing the advantages of the ASAP program.
GIS-based evaluation of the effectiveness of selective law enforcement campaigns in reducing crashes
(University of Alabama Libraries, 2015) Simandl, Jenna; Graettinger, Andrew Joseph; University of Alabama Tuscaloosa
State Departments of Transportation (DOTs) across the nation fund selective enforcement campaigns to improve traffic safety. The Alabama Department of Transportation (ALDOT) deploys a mobile selective law enforcement campaign targeting the negative driver behaviors that contribute to the most severe crashes, including speeding, driving under the influence, and failing to wear a seatbelt. The focus of this research was to integrate officer patrol routes, citations issued, crashes, and selective enforcement periods into one spatial and temporal map to evaluate the effectiveness of selective enforcement in reducing crashes along state routes in Alabama from August 1, 2010 to July 31, 2011. Structured Query Language (SQL) and Geographic Information System (GIS) technology were used to organize selective enforcement data into a relational database, geolocate Electronic Citations (eCitations), verify and locate selective enforcement areas, incorporate Electronic Crash (eCrash) data, and evaluate the decreased and/or increases in crash frequencies and the number of citations issued before and during selective enforcement. The approach to locate and verify selective enforcement locations successfully identified 21 locations across the state of Alabama. Statistical analysis was performed using a Paired Difference t-test. When evaluating the locations both by area type of urban or rural and collectively, there were significant increases in the number of citations issued, with an average 254% increase. There were marked decreases in the number of crashes when crashes were separately analyzed by the location type. P-values of 0.148 and 0.122 for urban and rural locations, respectively, confirm the decrease in crash frequency with 85% confidence. There were minimal decreases in the number of crashes when evaluating the locations collectively; however, there was a slight decrease in crash severity, with an average 2.45% decrease. Therefore, selective law enforcement efforts and the increase of issued citations along state routes in Alabama have started to improve public safety and decrease the number of crashes at select areas. Future work will involve strengthening the crash decreases with a proposed selective enforcement campaign recommendation, developing crash modification factors, and calculating a return of investment.
Identifying, anticipating, and mitigating freight bottlenecks on Alabama interstates
(University of Alabama Libraries, 2011) Anderson, Kenneth; Lindly, Jay K.; University of Alabama Tuscaloosa
This project establishes a framework for the creation and maintenance of a statewide strategy for identifying, anticipating, and mitigating freight bottlenecks on interstate highways for the state of Alabama. It uses a methodology established and developed by Cambridge Systematics for identifying and quantifying bottlenecks. This research identified a total of nine freight bottlenecks on Alabama interstates using 2006 traffic data supplied by ALDOT. These include six bottlenecks, termed "capacity" bottlenecks, which are caused by an insufficient capacity in relation to demand (where the ratio of Average Annual Daily Traffic to the hourly capacity of the roadway in passenger cars per hour is greater than eight) on a basic section of roadway. The other three bottlenecks are "interchange" bottlenecks, which are similar to capacity bottlenecks except that they occur at interchanges involving multiple interstates. The six sections of roadway identified as capacity bottlenecks follow: * Interstate 65 from Exit 252 to Exit 259B * Interstate 65 from Exit 238 to Exit 246 * Interstate 20/59 from Exit 123 to Exit 130 * Interstate 65 from Exit 247 to Exit 250 * Interstate 10 from 26A to Exit 27 * Interstate 10 from Exit 15B to Exit 17A The three interchanges identified as bottlenecks follow: * Interstate 459 at Interstate 65 * Interstate 20/59 at Interstate 65 * Interstate 20/59 diverge (into separate Interstate 20 and Interstate 59) A third type of bottleneck called a "roadway geometry" bottleneck involves congested roadways that have grades greater than 4.5% lengths exceeding one mile. However, none of these types of bottlenecks were identified on Alabama interstates because there is no stretch of interstate of that length with that steep of grade. Identification of bottleneck locations was done using a GIS database that was created specifically for use in this report. This database merged multiple, previously existing databases including the National Highway Planning Network, the Highway Performance Monitoring System, and the Freight Analysis Framework. Each of the bottlenecks identified were assigned a cost value for the delay that it causes in 2006 as well as in 2025 and 2040. This type of information is useful to planners when they are selecting sections of interstate highways for upgrade. Similarly, projections of delay cost were calculated for interstate road sections and interchanges that were classified as bottlenecks in year 2006. For example, the George C. Wallace Tunnel in Mobile, which is the capacity bottleneck on Interstate 10 from Exit 26A to Exit 27, had roughly $150,000 in delay to freight movements in 2006 but is expected to increase to $1,836,000 in delay by the year 2025. That is a greater than ten-fold increase. The report also lists methods through which the basic framework established in this report can be improved upon to provide greater accuracy in bottleneck identification and delay cost calculations.
Incorporating systems thinking approach in a multilevel framework for human-centered crash analysis
(Elsevier, 2019) Adanu, Emmanuel Kofi; Penmetsa, Praveena; Wood, Dustin; Jones, Steven L.
Variations that exist in the frequency and severities of crashes across regions may be due to differences in road user behaviors or indirectly due to differences in regional characteristics. Regional strategies towards “vision zero” road fatalities, consisting of appropriate safety policies and laws, supported with public education and backed by appropriate sanctions, have the ability to shape road user behaviors in the long term. In this paper, certain human-centered crash factors are viewed as the outcome of a hierarchical system made up of road users nested in regions, in a way that regional characteristics like policies and punitive measures influence road user behaviors. Hence, we propose a multilevel framework that captures driver characteristics and regional attributes that directly and indirectly affect crash outcomes. The concept was applied to crash data analysis for the state of Alabama, where it was found that the probability of a fatal crash involving a typical driver is 0.115. About 6.19% of the variability in the fatal crash rate involving drivers from the state is accounted for by the city and 3.84% is accounted for by the county of residence of the causal driver, leaving 89.97% of the variability to be accounted for by driver attributes or other crash contributing factors. Fatal crash rates varied significantly across the state and some crash factors were more pronounced among drivers from particular cities and counties. In view of these findings, specific countermeasures and structural adjustments may be targeted in locations with the highest proportions of risky driver behaviors.
Integrating Novel Connected Vehicle Event Data for Proactive Road Safety Improvement
(University of Alabama Libraries, 2024) Okafor, Sunday; Jones, Steven L.
Despite substantial progress in advancing road safety, fatalities and injuries from road crashes continue to pose a major public health concern globally. This dissertation explored the integration of novel Connected Vehicle (CV) hard braking event (HBE) data for proactive road safety improvement. It comprised four distinct but related studies. The first part of the dissertation presents a systematic review of existing studies on the use of CV events and related data in road safety research, focusing on data combinations, study contexts, and methodological approaches. The study adopted a modified PICO framework popularly used in medical science reviews by considering road crashes as a public health issue needing proactive intervention. A total of 21 papers were included in the final analysis based on a detailed synthesis of search results from multiple databases. The second part of the dissertation examined the correlation between historical crashes and HBE across different roadway functional classes and urbanized and rural areas in Alabama. The correlation was conducted at the segment level to provide a preliminary insight into the classes of roadways where HBE could be most appropriate as surrogates of historical crashes. The third part of the dissertation utilized multiple statistical approaches to investigate the potential integration of HBE as crash surrogates for proactive safety screening of arterial road networks. This study focused primarily on comparing the identified hotspots based on different crash types and HBE to justify the suitability of HBE as surrogates for proactive roadway screening. The fourth part of the dissertation employed an interpretable machine learning technique to examine the individual and interactive effects of HBE risk factors alongside traditional risk factors on crash frequency. This study provides insights into how the interaction of risk factors from CV, roadways, and traffic attributes could influence crash frequency, thereby providing additional information for proactive road safety improvement measures. Overall, this dissertation contributes to advancing road safety and provides valuable insights for the proactive evaluation of roadway safety performance by safety agencies to identify and remedy safety issues in advance, thereby limiting future crashes.
A macro-level analysis of safety data using geospatial techniques and spatial econometric methods and models
(University of Alabama Libraries, 2017) Zephaniah, Samwel Oyier; Jones, Steven L.; University of Alabama Tuscaloosa
Motor vehicle accidents are a source of many preventable injuries and deaths, worldwide. Several statistical and econometric models have been developed to predict and explain crash events. Research indicate that 93% of traffic accidents are due to human error. The objective of this research is twofold – first, to develop a macro level safety planning framework by identifying socioeconomic factors that influence crash frequencies and second, to characterize traffic congestion attributed to a crash events. To this effect, a Geographically Weighted Poisson Regression (GWPR) model, a suite of Spatial Econometric models and a Mixed Logit model were estimated. Data used included crash records from 2009 to 2013 in Alabama comprising 647,477 crash events. These included 4,814 crashes on Interstate 65 and 21,818 crashes related to Driving Under the Influence (DUI). Other data comprised socioeconomic data from US census, weather data, traffic data, spatial data from ESRI and crowd sourced speed data. Results indicate that DUI crash rates and frequencies at postal code level are predominantly influenced by rate of employment, income, population density, level of education, household size and housing characteristics. In addition, level of congestion attributed to a crash depends on factors including traffic volume, speed, weather, time of the event, severity of the crash, presence of physical barrier separating opposing traffic lanes, work zone, percent of heavy trucks and whether the crash occurred in an urban area or rural area. These results are unequivocal regarding the importance of geographic variation and heterogeneity in driver behavior and the general road safety.
Multi-perspective system-wide analyses of adaptive traffic signal control systems using microsimulation and contemporary data sources
(University of Alabama Libraries, 2016) Lidbe, Abhay Dnyaneshwar; Hainen, Alexander M.; University of Alabama Tuscaloosa
The primary function of traffic signals is to assign the right of way to vehicular and pedestrian traffic at intersections. Effective traffic signal system reduces congestion, increases intersection capacity, and improves other traffic related performance measures such as safety and mobility. To ensure these goals are met, traffic signals require updated timings to maintain proper operation. These updated signal timings impact not only traffic performance, but overall transportation system efficiency. Because traditional signal timing plans may not accommodate variable and unpredictable traffic demands, a more proactive approach is necessary to ensure properly timed and maintained traffic signals. Adaptive traffic control systems (ATCS) continually collect data and optimize signal timing on a real time basis thereby reducing the aforementioned drawbacks of traditional signal retiming. Understanding and characterizing how these systems are working is important to transportation engineers, and evaluating these systems can provide useful insights. The objective of this dissertation is to develop evaluation methodologies (both operational and economical) for adaptive traffic signal control that go beyond the traditional assessments that use traffic measures of effectiveness (MOEs). Case studies are conducted for Sydney Coordinated Adaptive Traffic System (SCATS) implementations in Alabama, which are useful in objective evaluations of ATCS (in general) for both their current and future operational environments by using microsimulation techniques and/or field data from contemporary data sources. The study contains detailed comparative analyses of traffic operations of the study corridors for existing peak hour traffic conditions under the previous time-of-day (TOD) plan and similar peak hour conditions after SCATS implementation. Although simulation analysis using VISSIM traffic microsimulation software is the primary methodological technique used for evaluating comparative performances, arterial data from other sources (Bluetooth MAC Address Matching and crowdsourced travel data) are also used to perform the evaluations, which is a novel application for this context. While past studies have considered either the arterial or its side-streets performances in their evaluations, this work explored a system-wide approach looking at the composite performance of both dimensions together. Finally, for transportation agencies which operate within budget constraints, it is important to know the real worth of attaining the benefits from ATCS implementations. The last chapter of this dissertation extends the evaluation methodology to include benefit-cost analysis (BCA) by evaluating the ATCS performance for both current and future traffic conditions. This information will be helpful for transportation agencies, planners, and practitioners to understand and justify their ATCS investment and also serve as a guideline for their future ITS projects.

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Browsing by Author "Jones, Steven L."

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