Alberto M Figueroa-Medina | University of Puerto Rico Mayaguez (original) (raw)
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Papers by Alberto M Figueroa-Medina
International Conference on Transportation and Development 2019
Advances in Human Factors of Transportation, 2019
Traffic crashes in suburban school zones pose a serious safety concern due to a higher presence o... more Traffic crashes in suburban school zones pose a serious safety concern due to a higher presence of school-age pedestrians and cyclists as well as potential speeding issues. A study that investigated speed selection and driver behavior in school zones was carried out using two populations from different topographical and cultural settings: Puerto Rico and Massachusetts. A school zone from Puerto Rico was recreated in driver simulation scenarios and local drivers who are familiar with the environment were used as subjects. The Puerto Rico school simulation scenarios were replicated with subjects from Massachusetts to analyze the impact of drivers’ familiarity on the school-roadway environment. Twenty-four scenarios were built with pedestrians, on-street parked vehicles, and traffic flow used as simulation variables in the experiment. Results are presented in terms of speed behavior, reaction to the presence of pedestrians, speed compliance, and mean reduction in speeds for both familiar and unfamiliar drivers.
Journal of Legal Affairs and Dispute Resolution in Engineering and Construction, 2019
AbstractThe increased use of smartphones during the last decade has resulted in thousands of cras... more AbstractThe increased use of smartphones during the last decade has resulted in thousands of crashes per year in the United States and its territories. Drivers’ usage increases are particularly con...
Transportation Research Record: Journal of the Transportation Research Board
Willingness-to-pay measures were estimated for users of the PR-22 Freeway in the Commonwealth of ... more Willingness-to-pay measures were estimated for users of the PR-22 Freeway in the Commonwealth of Puerto Rico. The first dynamic toll lane (DTL) facility in Puerto Rico started operations in 2013 on PR-22. The PR-22 segment examined consists of two reversible express lanes along the median with a dynamic pricing scheme and six general traffic lanes with a fixed toll rate. Willingness-to-pay for the DTL was assessed using the Van Westendorp Price Sensitivity Meter (VWPSM) analysis. Moreover, discrete choice analysis was used to estimate the users’ willingness to pay for travel time savings. The data used in this analysis was obtained through an online survey that presented participants with direct willingness-to-pay questions, toll lane choice scenarios, and, for declared DTL users, questions about their reasons for using the facility. The aggregate analysis of the VWPSM estimated a willingness-to-pay range for the DTL of 1.00to1.00 to 1.00to2.79, which is lower than the maximum toll rate of $4...
The focus placed on pedestrian safety is based on the alarming increase in fatalities in the U.S.... more The focus placed on pedestrian safety is based on the alarming increase in fatalities in the U.S. in recent years. The 6,283 pedestrian fatalities observed in 2018 was the largest number on record from the previous 28 years. The study of pedestrian behavior and the evaluation of new and innovative pedestrian safety countermeasures are needed to reduce road-related fatalities. The objective of this study was to carry out a roadway crossing experiment using virtual reality (VR) simulation equipment. The study analyzed the behavior of pedestrians when making the decision to cross at an uncontrolled location on a one-lane and a two-lane urban street. The experiment included eight scenarios showing different vehicle speeds and vehicle gap values. The goal was to measure the ability of the subjects to detect safe vehicle gap times in traffic to cross the road and their walking speeds when crossing. Comparisons between gender and age groups were made based on the factors measured in the ex...
Transportation Research Board 100th Annual MeetingTransportation Research BoardTransportation Research Board, 2021
Case Studies on Transport Policy, 2022
The motivation for this research was the lack of a protocol to apply an Unmanned Aerial Vehicle (... more The motivation for this research was the lack of a protocol to apply an Unmanned Aerial Vehicle (UAV) platform for traffic data collection and effectively analyze and evaluate incidents in high-speed multi-lane and freeway corridors. The ultimate purpose of this research study was to integrate the use of drones into real-time incident detection to assist in reducing congestion and delay, improve traffic operations, and enhance overall safety in the corridor and contiguous surface transportation networks. Phase I of the research project consisted of a comprehensive literature review, selection and acquisition of drones and drone training to develop the protocol, data collection using the drone platform and dual sensing technologies, and evaluation of vehicle detection algorithms.
Abstract: The study of highway crash occurrence and its causation has been a prominent research s... more Abstract: The study of highway crash occurrence and its causation has been a prominent research subject in recent decades due to its significant impact and cost to society. Highway crashes are random events that are caused by many and very different contributing factors. The ...
Accident Analysis & Prevention
Proceedings of the 17th LACCEI International Multi-Conference for Engineering, Education, and Technology: “Industry, Innovation, and Infrastructure for Sustainable Cities and Communities”, 2019
Innovations on intersection design have been the focus of recent developments in the US and aroun... more Innovations on intersection design have been the focus of recent developments in the US and around the world. The second installment of the Every Day Counts initiative (EDC-2) from the Federal Highway Administration (FHWA) promoted five new intersection designs. One of them was the Diverging Diamond Interchange (DDI). This innovative design has been implemented in several cities in the US to improve operations and safety. Puerto Rico is currently building its first DDI in the intersection of an arterial street and a freeway in the Municipality of Gurabo. This paper discusses the main characteristics of the DDI and presents a design framework from conception to implementation. This framework considers the geometric, environmental, and cultural influence in the design of a DDI, while also paying attention to the influence of non-motorized users and the continuous evaluation of the intersection by using driving simulation as part of the effective project implementation. Other topics discussed include safety evaluation, signaling, traffic influence, and the use of driving simulation into the determination of operational safety at a DDI. Also, the comparison between the conventional diamond interchange and the DDI, potential DDI issues from an operational point of view, and the objectives or goals of this type of intersection design are presented. A discussion of the benefits of using a driving simulator as a tool to evaluate a DDI and the importance of the data gathered in the process are also explained. Details of the implementation of this framework in Puerto Rico are presented as concluding remarks.
Transportation Research Record, 2005
The mean free-flow speed and its variability across drivers are considered important safety facto... more The mean free-flow speed and its variability across drivers are considered important safety factors. Despite a large body of past research on operating speeds, there is still much to learn about the factors of free-flow speeds, especially on tangent segments of two-lane rural highways. The roadway factors of speed dispersion across drivers are largely unknown. Also, the use of the entire free-flow speed distribution suggested by other authors has not been yet addressed. Consequently, the existing models are not aimed to evaluate the speed variability at a site. This paper presents free-flow speed models that identify factors of mean speed and speed dispersion on tangent segments and horizontal curves of two-lane rural highways. Ten different highway variables, six of them functioning as both mean speed and speed dispersion factors, were identified as speed factors on tangent segments. Four different highway and curve variables, two of them functioning as both mean speed and speed dispersion factors, were identified as speed factors on horizontal curves. The developed free-flow speed models have the same prediction capabilities as traditional ordinary least squares models developed for specific percentile speeds. The advantages of the developed models include predicting any user-specified percentile, involving more highway characteristics as speed factors than traditional regression models, and separating the impacts on mean speed from the impacts on speed dispersion.
The mean free-flow speed and its variability across drivers are considered important safety facto... more The mean free-flow speed and its variability across drivers are considered important safety factors. Much of the speed research has been devoted primarily to two-lane rural highways. There is still much to learn about the factors of free-flow speeds on four-lane highways. The roadway factors of speed dispersion across drivers are largely unknown. Also, the use of the entire free-flow speed distribution suggested by other authors has not been yet addressed. Consequently, the existing models are not aimed to evaluate the speed variability at a site. This paper presents free-flow speed models that identify factors of mean speed and speed dispersion on four-lane suburban and rural highways. Two panel data models are presented; one developed with ordinary least squares (OLS-PD) and another that accounts for the random effect (RE) from the observation sites. The models identified a number of significant highway characteristics; several of them represented as both mean speed and speed disp...
Safety is typically linked to the road geometry and speed, and speed is directly associated to th... more Safety is typically linked to the road geometry and speed, and speed is directly associated to the road characteristics through the risk perceived by drivers. This endogeneous relationship is not reflected in the current approach of estimating speed and safety effects using single-equation models. This paper presents the results of a study that evaluated road design characteristics, free-flow speeds, crashes, and risk perception of drivers in four-lane highway segments located in suburban and rural areas. The results from single-equation speed and crash models were compared to speed and crash models developed simultaneously. The system of equations includes the effect of speed in the safety model while the effect of crash rate is included in the speed model. The road characteristics are considered exogenous variables in the system. The use of the simultaneous equations approach to calibrate the proposed system of relationships, aside from being the correct formulation to model the e...
In an effort to foster improved public involvement in the planning of transportation projects, an... more In an effort to foster improved public involvement in the planning of transportation projects, and within the framework of Context Sensitive Design, a method is developed that collects community preference at the inception of a project via questionnaire. Preferences are expressed with respect to a pre-selected set of criteria that represent sustainable transportation design features. After quantitative analysis to rank preferences, several “fly-through” visuals are created to capture various levels of community preference. These visuals can then be presented to the community for further comment. This methodology is implemented in Dulces Labios, which is a coastal community in the municipality of Mayaguez, Puerto Rico. The study demonstrates that it is feasible to collect community preference data as a means to inform the formulation of design options, and to interpret these preferences visually, in a manner that is accessible to people in a community with varying levels of education...
Ite Journal-institute of Transportation Engineers, 2018
International Conference on Transportation and Development 2019
Advances in Human Factors of Transportation, 2019
Traffic crashes in suburban school zones pose a serious safety concern due to a higher presence o... more Traffic crashes in suburban school zones pose a serious safety concern due to a higher presence of school-age pedestrians and cyclists as well as potential speeding issues. A study that investigated speed selection and driver behavior in school zones was carried out using two populations from different topographical and cultural settings: Puerto Rico and Massachusetts. A school zone from Puerto Rico was recreated in driver simulation scenarios and local drivers who are familiar with the environment were used as subjects. The Puerto Rico school simulation scenarios were replicated with subjects from Massachusetts to analyze the impact of drivers’ familiarity on the school-roadway environment. Twenty-four scenarios were built with pedestrians, on-street parked vehicles, and traffic flow used as simulation variables in the experiment. Results are presented in terms of speed behavior, reaction to the presence of pedestrians, speed compliance, and mean reduction in speeds for both familiar and unfamiliar drivers.
Journal of Legal Affairs and Dispute Resolution in Engineering and Construction, 2019
AbstractThe increased use of smartphones during the last decade has resulted in thousands of cras... more AbstractThe increased use of smartphones during the last decade has resulted in thousands of crashes per year in the United States and its territories. Drivers’ usage increases are particularly con...
Transportation Research Record: Journal of the Transportation Research Board
Willingness-to-pay measures were estimated for users of the PR-22 Freeway in the Commonwealth of ... more Willingness-to-pay measures were estimated for users of the PR-22 Freeway in the Commonwealth of Puerto Rico. The first dynamic toll lane (DTL) facility in Puerto Rico started operations in 2013 on PR-22. The PR-22 segment examined consists of two reversible express lanes along the median with a dynamic pricing scheme and six general traffic lanes with a fixed toll rate. Willingness-to-pay for the DTL was assessed using the Van Westendorp Price Sensitivity Meter (VWPSM) analysis. Moreover, discrete choice analysis was used to estimate the users’ willingness to pay for travel time savings. The data used in this analysis was obtained through an online survey that presented participants with direct willingness-to-pay questions, toll lane choice scenarios, and, for declared DTL users, questions about their reasons for using the facility. The aggregate analysis of the VWPSM estimated a willingness-to-pay range for the DTL of 1.00to1.00 to 1.00to2.79, which is lower than the maximum toll rate of $4...
The focus placed on pedestrian safety is based on the alarming increase in fatalities in the U.S.... more The focus placed on pedestrian safety is based on the alarming increase in fatalities in the U.S. in recent years. The 6,283 pedestrian fatalities observed in 2018 was the largest number on record from the previous 28 years. The study of pedestrian behavior and the evaluation of new and innovative pedestrian safety countermeasures are needed to reduce road-related fatalities. The objective of this study was to carry out a roadway crossing experiment using virtual reality (VR) simulation equipment. The study analyzed the behavior of pedestrians when making the decision to cross at an uncontrolled location on a one-lane and a two-lane urban street. The experiment included eight scenarios showing different vehicle speeds and vehicle gap values. The goal was to measure the ability of the subjects to detect safe vehicle gap times in traffic to cross the road and their walking speeds when crossing. Comparisons between gender and age groups were made based on the factors measured in the ex...
Transportation Research Board 100th Annual MeetingTransportation Research BoardTransportation Research Board, 2021
Case Studies on Transport Policy, 2022
The motivation for this research was the lack of a protocol to apply an Unmanned Aerial Vehicle (... more The motivation for this research was the lack of a protocol to apply an Unmanned Aerial Vehicle (UAV) platform for traffic data collection and effectively analyze and evaluate incidents in high-speed multi-lane and freeway corridors. The ultimate purpose of this research study was to integrate the use of drones into real-time incident detection to assist in reducing congestion and delay, improve traffic operations, and enhance overall safety in the corridor and contiguous surface transportation networks. Phase I of the research project consisted of a comprehensive literature review, selection and acquisition of drones and drone training to develop the protocol, data collection using the drone platform and dual sensing technologies, and evaluation of vehicle detection algorithms.
Abstract: The study of highway crash occurrence and its causation has been a prominent research s... more Abstract: The study of highway crash occurrence and its causation has been a prominent research subject in recent decades due to its significant impact and cost to society. Highway crashes are random events that are caused by many and very different contributing factors. The ...
Accident Analysis & Prevention
Proceedings of the 17th LACCEI International Multi-Conference for Engineering, Education, and Technology: “Industry, Innovation, and Infrastructure for Sustainable Cities and Communities”, 2019
Innovations on intersection design have been the focus of recent developments in the US and aroun... more Innovations on intersection design have been the focus of recent developments in the US and around the world. The second installment of the Every Day Counts initiative (EDC-2) from the Federal Highway Administration (FHWA) promoted five new intersection designs. One of them was the Diverging Diamond Interchange (DDI). This innovative design has been implemented in several cities in the US to improve operations and safety. Puerto Rico is currently building its first DDI in the intersection of an arterial street and a freeway in the Municipality of Gurabo. This paper discusses the main characteristics of the DDI and presents a design framework from conception to implementation. This framework considers the geometric, environmental, and cultural influence in the design of a DDI, while also paying attention to the influence of non-motorized users and the continuous evaluation of the intersection by using driving simulation as part of the effective project implementation. Other topics discussed include safety evaluation, signaling, traffic influence, and the use of driving simulation into the determination of operational safety at a DDI. Also, the comparison between the conventional diamond interchange and the DDI, potential DDI issues from an operational point of view, and the objectives or goals of this type of intersection design are presented. A discussion of the benefits of using a driving simulator as a tool to evaluate a DDI and the importance of the data gathered in the process are also explained. Details of the implementation of this framework in Puerto Rico are presented as concluding remarks.
Transportation Research Record, 2005
The mean free-flow speed and its variability across drivers are considered important safety facto... more The mean free-flow speed and its variability across drivers are considered important safety factors. Despite a large body of past research on operating speeds, there is still much to learn about the factors of free-flow speeds, especially on tangent segments of two-lane rural highways. The roadway factors of speed dispersion across drivers are largely unknown. Also, the use of the entire free-flow speed distribution suggested by other authors has not been yet addressed. Consequently, the existing models are not aimed to evaluate the speed variability at a site. This paper presents free-flow speed models that identify factors of mean speed and speed dispersion on tangent segments and horizontal curves of two-lane rural highways. Ten different highway variables, six of them functioning as both mean speed and speed dispersion factors, were identified as speed factors on tangent segments. Four different highway and curve variables, two of them functioning as both mean speed and speed dispersion factors, were identified as speed factors on horizontal curves. The developed free-flow speed models have the same prediction capabilities as traditional ordinary least squares models developed for specific percentile speeds. The advantages of the developed models include predicting any user-specified percentile, involving more highway characteristics as speed factors than traditional regression models, and separating the impacts on mean speed from the impacts on speed dispersion.
The mean free-flow speed and its variability across drivers are considered important safety facto... more The mean free-flow speed and its variability across drivers are considered important safety factors. Much of the speed research has been devoted primarily to two-lane rural highways. There is still much to learn about the factors of free-flow speeds on four-lane highways. The roadway factors of speed dispersion across drivers are largely unknown. Also, the use of the entire free-flow speed distribution suggested by other authors has not been yet addressed. Consequently, the existing models are not aimed to evaluate the speed variability at a site. This paper presents free-flow speed models that identify factors of mean speed and speed dispersion on four-lane suburban and rural highways. Two panel data models are presented; one developed with ordinary least squares (OLS-PD) and another that accounts for the random effect (RE) from the observation sites. The models identified a number of significant highway characteristics; several of them represented as both mean speed and speed disp...
Safety is typically linked to the road geometry and speed, and speed is directly associated to th... more Safety is typically linked to the road geometry and speed, and speed is directly associated to the road characteristics through the risk perceived by drivers. This endogeneous relationship is not reflected in the current approach of estimating speed and safety effects using single-equation models. This paper presents the results of a study that evaluated road design characteristics, free-flow speeds, crashes, and risk perception of drivers in four-lane highway segments located in suburban and rural areas. The results from single-equation speed and crash models were compared to speed and crash models developed simultaneously. The system of equations includes the effect of speed in the safety model while the effect of crash rate is included in the speed model. The road characteristics are considered exogenous variables in the system. The use of the simultaneous equations approach to calibrate the proposed system of relationships, aside from being the correct formulation to model the e...
In an effort to foster improved public involvement in the planning of transportation projects, an... more In an effort to foster improved public involvement in the planning of transportation projects, and within the framework of Context Sensitive Design, a method is developed that collects community preference at the inception of a project via questionnaire. Preferences are expressed with respect to a pre-selected set of criteria that represent sustainable transportation design features. After quantitative analysis to rank preferences, several “fly-through” visuals are created to capture various levels of community preference. These visuals can then be presented to the community for further comment. This methodology is implemented in Dulces Labios, which is a coastal community in the municipality of Mayaguez, Puerto Rico. The study demonstrates that it is feasible to collect community preference data as a means to inform the formulation of design options, and to interpret these preferences visually, in a manner that is accessible to people in a community with varying levels of education...
Ite Journal-institute of Transportation Engineers, 2018