Paul P Jovanis

Pennsylvania State University | Penn State · Department of Civil and Environmental Engineering

The increasing availability and implementation of in-vehicle data recorder (IVDR) technologies has resulted in an increased number of safety applications based on the behavior of drivers during actual driving. The objective of this study is to formulate a flexible framework for IVDR data analysis that has the capability to include roadway geometric...

The Highway Safety Manual provides multiple methods that can be used to identify sites with promise (SWiPs) for safety improvement. However, most of these methods cannot be used to identify sites with specific problems. Furthermore, given that infrastructure funding is often specified for use related to specific problems/programs, a method for iden...

In recent years, the increasing availability of in-vehicle data recorder technologies has resulted in more safety studies that have unobtrusively observed the behavior of drivers during actual driving. The research in this paper proposes and applies a flexible analysis structure that can be applied to data that reflect events of interest - includin...

Over the course of the study, under the direction of the National Academies, and with the support of VTTI, the teams at each of the six study centers successfully • Identified and contacted more than 16,358 people who expressed some interest in participating in the study. Of these, 3,247 became primary test participants in targeted demographic age...

This study responds to the need to screen events observed during naturalistic driving studies to derive a set of crashes and near crashes with common etiologies; these crashes are referred to as "well-defined surrogate events?' Two factors are critical to the identification of these well-defined surrogate events: selection of screening criteria and...

There is a need to extend and refine the use of crash surrogates to enhance safety analyses. This is particularly true given opportunities for data collection presented by naturalistic driving studies. This paper connects the original research on traffic conflicts to the contemporary literature concerning crash surrogates using the crash-to-surroga...

There is a need to explore the relationship, if any, between the probability of a crash and the hours worked by truck drivers. The need arises from the continued adjustment of federal hours of service regulations for truck drivers. This research used data logs from less-than-truckload carrier operations in 2004 to 2005 and in 2010 to estimate the p...

Naturalistic driving studies have been conducted over the past 5 years or more and have commonly reviewed video and kinematic data to identify and analyze crash, near-crash, and critical-incident events. But statistical methods that are applicable to these event data are needed. This paper addresses two issues in model development for naturalistic...

A case-control study of 231 truck crashes (and 462 controls) was completed with data from three trucking companies from 2004, when new hours-of-service (HOS) regulations went into effect in the United States. Analysis using time-dependent logistic regression indicates that increased crash risk is associated with hours of driving, with risk increase...

Recent research has shown the importance of spatial correlation in road crash models. However, many different spatial correlation structures are possible; hence, different segment neighboring structures are tested to establish the most promising one in the context of modeling crash frequency in road networks. Furthermore, a multilevel approach is u...

There is a need to evaluate low-cost safety strategies that states may implement as part of their Strategic Highway Safety Plan. FHWA organized a pooled fund study of 26 states to evaluate several low-cost safety strategies, including the reallocation of total paved width. This study identifies whether it is safer to increase lane width or increase...

Traditionally, highway safety analyses have used univariate Poisson or negative binomial distributions to model crash counts for different levels of crash severity. Because unobservables or omitted variables are shared across severity levels, however, crash counts are multivariate in nature. This research uses full Bayes multivariate Poisson lognor...

Recently completed naturalistic (i.e., unobtrusive) driving studies provide safety researchers with an unprecedented opportunity to study and analyze the occurrence of crashes and a range of near-crash events. Rather than focus on the details of the events immediately before the crash, this study seeks to identify methodological paradigms that can...

Despite the evident spatial character of road crashes, limited research has been conducted in road safety analysis to account for spatial correlation; further, the practical consequences of this omission are largely unknown. The purpose of this research is to explore the effect of spatial correlation in models of road crash frequency at the segment...

The FHWA has been seeking to better integrate the use of surface weather information into traffic operations (e.g., National Academy of Sciences, 2004). One area of particular interest has been the use of enhanced weather information and forecasting to improve response to winter road maintenance demands (e.g., Mahoney, 2003; Boon and Cluett, 2002)....

There is a need to investigate educational offerings in highway safety available through engineering, public health, and injury prevention programs at universities in the United States. A series of surveys was distributed to universities and transportation engineering research centers throughout the United States from March 2004 to March 2005, requ...

The use of observational data to estimate safety effectiveness for changes in shoulder width is explored. Common statistical models are applied to estimate safety effectiveness of shoulder width; however, two unique approaches, the case control and the cohort methods, are used in the design stage. Case control and cohort designs are common methods...

There is a need to better understand and quantify the safety implications of geometric improvements and countermeasures. A commonly accepted measure of safety effectiveness is the crash modification factor (CMF) defined as the expected number of crashes with a countermeasure divided by the number expected without the countermeasure. This paper eval...

Road segments with elevated weather-related crash risk are identified using historical crash and traffic information for Pennsylvania. The ranking of sites is performed with Full Bayesian Hierarchical Models with random effects using two ranking criteria: the expected excess crash frequency (compared to similar sites) and the relative risk (the rat...

Using injury and fatal crash data for Pennsylvania for 1996-2000, full Bayes (FB) hierarchical models (with spatial and temporal effects and space-time interactions) are compared to traditional negative binomial (NB) estimates of annual county-level crash frequency. Covariates include socio-demographics, weather conditions, transportation infrastru...

The detailed analysis of preexisting crash and noncrash data representing an estimated 16 million vehicle miles of travel has revealed strong consistency between crash analysis using data from the 1980s and field experiments conducted in the 1990s. Time of day of driving is associated with crash risk: night and early morning driving has elevated ri...

A series of studies including: lab experiments, Computer Assisted Telephone Interviews (CATI), and mailout- and-call-in surveys were developed as part of a market research project, administered in the Davis and Sacramento, CA areas from 1996 to 1997. The objective of the research was to examine the suitability of advanced transportation services an...

The detailed analysis of preexisting crash and noncrash data representing an estimated 16 million vehicle miles of travel has revealed strong consistency between crash analysis using data from the 1980s and field experiments conducted in the 1990s. Time of day of driving is associated with crash risk: night and early morning driving has elevated ri...

A study of the usability of statewide web-based traveler information systems was conducted to assess their effectiveness in conveying, road and weather information to travelers. Guidelines from traveler information systems and the website design literature were coalesced to create an assessment framework to include important elements from a user's...

If real-time driver en route guidance advice does not meet driver preferences (e.g., preference for taking the freeway) or the advice is not correct, drivers are very likely to ignore the information, and the guidance system becomes ineffective in their route choice no matter how advanced the system. There is a need to investigate the factors affec...

Numerous driver, vehicle, roadway, and environmental factors contribute to crash-injury severity. In addition to main effects, interactions between factors are very likely to be significant. The large number of potentially important factors, combined with the complex nature of crash etiology and injury outcome, present significant challenges to the...

Recent developments in information technologies, providing new ways to disseminate and use information, may help alleviate congestion, reduce user cost and time, and enhance safety. This influence of technology use, however, is mediated by telecommunication and information technology ownership and use. A multivariate probit model specification is u...

This study focused on determining whether advanced transportation services and information systems could enhance the mobility of disabled and elderly travelers in their use of transit, paratransit, or advanced paratransit services. The advanced proposed systems included regular paratransit and two advanced paratransit systems (real-time paratransit...

This study examined the potential of advanced information systems to increase the mobility of disabled travelers using public transportation. A stated preference survey inquired as to whether subjects would make more trips by transit, paratransit, and/or real-time paratransit if kiosk, on-board, in-home, and/or personal information systems were ava...

Experiments were conducted in a fixed-base, high-fidelity simulator to evaluate selected in-vehicle route guidance systems. Drivers navigated a simulated network using five route guidance systems: paper map, head-down turn-by-turn display, head-down electronic route map, head-up turn-by-turn display, and an audio guidance system. The primary measur...

This paper presents a statistical analysis of commuters' route choice including the effect of traffic information. The paper utilizes data collected from two stated preference survey techniques. Two route choice models were estimated. The first model used five hypothetical binary choice sets collected in a computer-aided telephone interview. The ob...

A study of the effects of advanced transit information on commuter propensity to use transit is described. A computer-aided telephone interview was designed and conducted in Sacramento and San Jose, California. The most important information items that nontransit users seek about the transit services available to them is investigated. Using a custo...

Advanced transit information can contribute to the improvement of transit service levels by providing their users with information on several transit attributes. These systems might encourage non-transit users to use public transit if the desired information is provided. This paper presents a study into the effects of advanced transit information s...

Several intelligent vehicle-highway system demonstration projects are currently assessing the feasibility of using probe vehicles to collect real-time traffic data for advanced traffic management and information systems. They have used a variety of criteria to determine the number of probes necessary, but few generalizable algorithms have been deve...

Several intelligent vehicle–highway system demonstration projects are currently assessing the feasibility of using probe vehicles to collect realtime traffic data for advanced traffic management and information systems. They have used a variety of criteria to determine the number of probes necessary, but few generalizable algorithms have been devel...

A study of the effects of advanced transit information on commuter propensity to use transit is described. A computer-aided telephone interview was designed and conducted in Sacramento and San Jose, California. The most important information items that nontransit users seek about the transit services available to them is investigated. Using a custo...

Experiments were conducted in a fixed base high fidelity simulator to study the effect of in-vehicle route guidance devices on the attentional demands of driving. Drivers navigated a simulated network using five route guidance systems: paper map, heads-down turn-by-turn display, heads-down electronic route map, heads-up turn-by-turn display, and au...

Experiments were conducted in a moderate-fidelity desktop simulator to investigate the attentional demand of four types of turn-by-turn route guidance displays. Subjects had to perform a tracking task with the mouse and record their decision to turn left, go straight, or turn right at an intersection, by pressing the left, middle or right mouse but...

In this study, evaluation of impacts on users for transit information system usage is done in two stages. In the first stage, a simple transit information system was developed and tested with in-house participants (subjects). Due to the lack of literature in similar studies, the first stage experiments help in designing an actual prototype for cond...

This paper describes work performed at U.C. Davis in the area of Advanced Travel Information Systems (ATIS). The project develops a Voice Operated Information System (VOIS) for drivers' information and guidance. The principal aim of this work was to develop a suitable interface for the untrained user (driver), and investigate the degree to which di...

Computer simulation is often-used methodology to study travel behavior as a cost effective alternative to field studies. In this study, we utilize PC-based computer simulation to study the effects of information on route choice and learning. Building on the efforts of a prior stage of simulation, further experiments that utilize an expanded traffic...

A study was conducted to determine ways in which travel time variation affects route choice behavior and the potential interplay among travel time variation, traffic information acquisition, and route choice. In a computer-aided telephone interview, a stated preference section was included to investigate this issue, and 564 respondents in the Los A...

A statistical analysis of commuters' route choice is presented. A binary logit model with normal mixing distribution using stated preference repeated-measurement data is estimated. General descriptive statistics are initially introduced in the paper to explore various route choice criteria and provide the basis for model estimation. The analysis is...

Computer-based simulation experiments were designed and conducted using 100 regular commuters from the Sacramento, Calif. region. By using computer-based simulation, a hypothetical traffic network was created and dynamic route choice data were collected for a sequence of 20 simulated trial days for each participant. A fractional factorial experimen...

The survey approach is often used in studying drivers' route choice behavior. Surveys enable the researcher to analyze route choice behavior and the effects of traffic information directly from reported behavior and perceptions of the respondent. A sample that represents well the population in the study area could facilitate better understanding of...

A computer based microsimulation was used to collect traveler behavior data during the analysis of route choice problems. The simulation collected 32 sequential binary route choice decisions made by 343 subjects under various experimental conditions. The experimental factors included information accuracy, feedback, provision of descriptive rational...

Containing traffic congestion is a serious international problem. Advanced traveler information systems (ATIS) have been proposed as one of many solutions to this problem. ATIS could improve system travel times and speeds by providing drivers with real-time traffic information. It could also provide pre-trip information. In order to design systems...

Experiments were conducted in a driving simulator developed by the Hughes Aircraft Corporation to study the human factors aspects of route guidance systems. The primary objective of this research was to study how in-vehicle route guidance system attributes, driver characteristics, and traffic conditions affect driving performance. Four types of rou...

A model of driver's route choice behavior under advanced traveler information system (ATIS) is developed based on data collected from learning experiments using interactive computer simulation. The experiment subjected drivers to 32 simulated days in which they were to choose between the freeway or a side road. A neural network model is used as a c...

A model of drivers' route choice behavior under advanced traveler information systems (ATIS) is developed based on data collected from learning experiments using interactive computer simulation. A neural network model is used as a convenient modeling technique in the analysis. Results indicated that most subjects made route choices based mainly on...

This paper describes the experimental analysis techniques and modelling efforts applied to sequential pre-trip route choice behavior data under the influence of an Advanced Traveler Information System (ATIS). This effort is the first step in a process to develop a basic understanding of the factors which influence route choice and how ATIS will aff...

This research is aimed at the identification of all types of accidents that have occurred on freeways which may affect the vehicle movement in the assumed automated left lane. The emphasis was on six-lane or more urban freeways. The accident data was obtained from the California TASAS ( Traffic Accidents Surveillance and Analysis System) data base...

This paper presents a statistical analysis of commuters' route choice behavior and the influence of traffic information. The analysis is based on a 1992 computer-aided telephone interview survey of Los Angeles area morning commuters. The results underscore the important relationship between the use of traffic information and the propensity to chang...

This report reviews the recent studies adopted in order to understand drivers' behavior, and in particular, behavior when influenced by an Advanced Traveler Information System (ATIS). Different approaches were used in these studies: field experiments, route choice surveys, interactive computer simulation games, route choice simulation and/or modeli...

This report documents the results of a user needs assessment conducted to define the concept of real-time ridesharing, and identify the problems that are to be addressed by the proposed Real-Time Rideshare Matching System. The user needs are then utilized to develop functional requirements for the real-time rideshare matching system. The functional...

A method has been developed to estimate the relative accident risk posed by different patterns of driving over a multiday period. The procedure explicitly considers whether a driver is on duty or off duty for each half hour of each day during the period of analysis. From a data set of over 1,000 drivers, nine distinct driving patterns are identifie...

A conceptual framework for accident occurrence is developed based on the principle of the driver as an information processor. The framework underlies the development of a modeling approach that is consistent with the definition of exposure to risk as a repeated trial. Survival theory is proposed as a statistical technique that is consistent with th...

The analysis of discrete accident data and aggregate exposure data frequently necessitates compromises that can obscure the relationship between accident occurrence and potential causal risk components. One way to overcome these difficulties is to develop a model of accident occurrence that includes accident and exposure data at a mathematically co...

Researchers at the University are engaged in two projects related to the testing of in-vehicle navigation systems. One project is concerned with the interrelationship between the given route guidance information, the driver's belief or anticipation, and the route choice made by the driver. Additionally, the impact of alternative route guidance sche...

Industry-supplied data allowed a structured statistical comparison of the safety performance of tractor-semitrailers (singles) and doubles by comparing their accident experience on the same routes for 3 years. This paired structure essentially controls for roadway, environment and traffic conditions. Separate comparisons of vehicle safety performan...

A framework to analyze the impact of the new electronic communication technologies on transportation systems in the business setting has been proposed. A component of the framework that focuses on the media choice processes of individuals was empirically tested using scenarios in which the physical mail media, courier services, the telephone, voice...

Data are obtained from ten intersection approaches for twenty-five 15-minute analysis periods. Saturation flows in the field are significantly higher than those in the manual. A value of nearly 2,000 vehicles per hour of green per lane (vphgpl) is consistently observed at field sites where the Highway Capacity Manual (HCM) estimates values of 1,800...

A model of communications media choice in business organizations is formulated based upon the results of exploratory interviews and the consumer choice literature. Choice is modelled as a function of organizational characteristics, individual characteristics, communication activity characteristics, communication initiator-recipient relationships an...

Coordinated timing plans may be developed for actuated signal systems but all existing optimization methods require that each actuated signal be converted to its nearest equivalent pretimed unit. Using bandwidth maximization as a starting point, a new procedure is developed that specifically accounts for actuated timing flexibility. Yield points an...

For U.S. children of preschool and school age, fatal pedestrian injury is more common than fatal passenger injury, but there is no agreement on preventive approaches and their efficacy. Development of preventive measures requires understanding of how and why such injuries occur, which in turn requires better methods to sort out the many factors whi...

Consideration of highway safety studies in a time-space domain is used to introduce the concept that different study designs result in different underlying probability distributions describing accident occurrence. Poisson regression is proposed as a superior alternative to conventional linear regression for many safety studies because it requires s...

A method for identifying control subareas in traffic signal networks has been developed and tested with data from the Miami, Florida, business district. The procedure combines the use of cluster and discriminant analysis to group signalized intersections. Unlike existing procedures which use degrees of association between adjacent signals, the mult...

Flexible work hours have been promoted as a low-cost approach to improve the productivity of the existing transportation system. However, analytical tools are needed to evaluate the impact such policies have on workers' arrival time choices. This paper develops a behaviorally-based structure, using utility maximization concepts, to relate travel, f...

Transit agencies are currently facing a multitude of problems, including declining ridership, reduced government subsidies, and increased operating costs. Rather than focus exclusively on investments and options that change the characteristics of transportation system supply, agencies can explore options that change the characteristics of the trave...

The traffic network model, TRANSYT 6, has been modified to include fuel consumption and vehicle emission impacts, as well as modal and spatial demand responses. Tests on a 5-mile section at Wilshire Boulevard in Los Angeles indicate that the most promising strategies from an environmental and passenger productivity viewpoint appear to be exclusive...

The traffic network model, TRANSYT 6, has been modified to include fuel consumption and vehicle emission impacts, as well as modal and spatial demand responses. Tests on a 5-mile section at Wilshire Boulevard in Los Angeles indicate that the most promising strategies from an environmental and passenger productivity viewpoint appear to be exclusive...

This paper addresses methodological issues faced in the development of a study to assess two issues related to user perception of level of service (LOS) at signalized intersections: (1) the appropriateness of the current Highway Capacity Manual levels of service for signalized intersections in terms of users' time-estimating capabilities and LOS pe...

: Changes in the U.S. hours of service policy in January 2004 argue for an assessment of the safety implications of the new policy. Time-dependent logistic regression and case-control sampling are applied to derive a sample of 231 crashes and 462 non-crashes during 2004 for three national-scale trucking companies. The analysis focuses on changes in...

Thesis (Ph. D. in Engineering)--University of California, Berkeley, June 1980. Includes bibliographical references.

Thesis supervisor: Paul P. Jovanis. Thesis (B.S.)--Pennsylvania State University, 2004. Library holds archival microfiche negative and service copy.