Search

Search Results

• 1. [Article] Multi-Criteria Trucking Freeway Performance Measures in Congested Corridors

  Research was undertaken to develop multicriteria tools for measuring and analyzing the impact of recurring and nonrecurring congestion on freight. Unlike previous studies, this work used several distinct ...

  Citation × Citation Citation Abstract Copy Title: Multi-Criteria Trucking Freeway Performance Measures in Congested Corridors Author: Figliozzi, Miguel, Wheeler, Nikki Year: 2011 Research was undertaken to develop multicriteria tools for measuring and analyzing the impact of recurring and nonrecurring congestion on freight. Unlike previous studies, this work used several distinct data sources to analyze the effects of congestion on I-5 in the Portland, Oregon, metropolitan area: Global Positioning System data from commercial trucks, Oregon Department of Transportation corridor travel time loop data, and incident data. A new methodology and algorithms combine these data sources and estimate the impact of recurrent and nonrecurrent congestion on reliability and delays, costs, and emissions of freight movements. The results suggest that traditional traffic sensor data tend to underestimate the impact of congestion on travel times and variability of commercial vehicles. Congestion is detrimental not only for carriers' and shippers' costs but also for the planet because of increases in greenhouse gas emissions and for the local community because of increases in oxides of nitrogen, particulate matter, and other harmful pollutants. The developed methodology can provide useful freight operation and performance data for the freight community, transportation decision makers, and other transportation stakeholders. For more information: http://archives.pdx.edu/ds/psu/11487 Title: Multi-Criteria Trucking Freeway Performance Measures in Congested Corridors Author: Figliozzi, Miguel, Wheeler, Nikki Year: 2011 Research was undertaken to develop multicriteria tools for measuring and analyzing the impact of recurring and nonrecurring congestion on freight. Unlike previous studies, this work used several distinct data sources to analyze the effects of congestion on I-5 in the Portland, Oregon, metropolitan area: Global Positioning System data from commercial trucks, Oregon Department of Transportation corridor travel time loop data, and incident data. A new methodology and algorithms combine these data sources and estimate the impact of recurrent and nonrecurrent congestion on reliability and delays, costs, and emissions of freight movements. The results suggest that traditional traffic sensor data tend to underestimate the impact of congestion on travel times and variability of commercial vehicles. Congestion is detrimental not only for carriers' and shippers' costs but also for the planet because of increases in greenhouse gas emissions and for the local community because of increases in oxides of nitrogen, particulate matter, and other harmful pollutants. The developed methodology can provide useful freight operation and performance data for the freight community, transportation decision makers, and other transportation stakeholders. For more information: http://archives.pdx.edu/ds/psu/11487 Close

• 2. [Article] Evaluating the Use of Crowdsourcing as a Data Collection Method for Bicycle Performance Measures and Identification of Facility Improvement Needs

  This research developed a smartphone application called ORcycle to collect cyclists’ routes, users, and comfort levels. ORcycle combines GPS revealed route data collection with new questionnaires that ...

  Citation × Citation Citation Abstract Copy Title: Evaluating the Use of Crowdsourcing as a Data Collection Method for Bicycle Performance Measures and Identification of Facility Improvement Needs Author: Figliozzi, Miguel A., Blanc, Bryan Philip Year: 2015 This research developed a smartphone application called ORcycle to collect cyclists’ routes, users, and comfort levels. ORcycle combines GPS revealed route data collection with new questionnaires that try to elicit cyclists’ attitudes as well as comfort levels and factors that influence their perceived comfort and route choice. The new questionnaires were developed to better understand how cyclists’ comfort levels are affected by route characteristics, route stressors, safety reports, cyclists’ demographics, and cyclists’ cycling attitude. Preliminary results show that many trip characteristics, route choice factors, route stressors and demographic variables are correlated with comfort levels. ORcycle is the first statewide deployment of a smartphone application to collect bicycle specific safety and crash data in addition to travel and comfort data. Potential applications that can take advantage of the ORcycle data include: comfort and route models, prioritization of network improvements, and crash and injury risk models. Title: Evaluating the Use of Crowdsourcing as a Data Collection Method for Bicycle Performance Measures and Identification of Facility Improvement Needs Author: Figliozzi, Miguel A., Blanc, Bryan Philip Year: 2015 This research developed a smartphone application called ORcycle to collect cyclists’ routes, users, and comfort levels. ORcycle combines GPS revealed route data collection with new questionnaires that try to elicit cyclists’ attitudes as well as comfort levels and factors that influence their perceived comfort and route choice. The new questionnaires were developed to better understand how cyclists’ comfort levels are affected by route characteristics, route stressors, safety reports, cyclists’ demographics, and cyclists’ cycling attitude. Preliminary results show that many trip characteristics, route choice factors, route stressors and demographic variables are correlated with comfort levels. ORcycle is the first statewide deployment of a smartphone application to collect bicycle specific safety and crash data in addition to travel and comfort data. Potential applications that can take advantage of the ORcycle data include: comfort and route models, prioritization of network improvements, and crash and injury risk models. Close

• 3. [Article] Algorithms for Studying the Impact of Travel Time Reliability Along Multisegment Trucking Freight Corridors

  Performance measures allow planners and engineers to monitor and evaluate transportation facilities or projects and to justify the allocation of funds among alternative transportation improvement options. ...

  Citation × Citation Citation Abstract Copy Title: Algorithms for Studying the Impact of Travel Time Reliability Along Multisegment Trucking Freight Corridors Author: Figliozzi, Miguel, Wheeler, Nikki, Albright, Eric, Walker, Lindsay, Sarkar, Shreemoyee, Rice, Danielle Year: 2011 Performance measures allow planners and engineers to monitor and evaluate transportation facilities or projects and to justify the allocation of funds among alternative transportation improvement options. To capture the impact of corridor congestion on freight vehicles, new tools and methodologies are developed to analyze data from commercial vehicles and produce performance measures such as travel time, speed, and travel time reliability. Because long freight corridors comprise segments with varying reliability characteristics, the objective was to develop a programming logic that would use available truck Global Positioning System data to (a) identify natural segments or regions in a corridor between urban centers, Interstate junctions, or rural areas and (b) estimate corridorwide impact of travel time unreliability. The case study presented investigates the I-5 corridor in Oregon. The research applies statistical techniques to compute vehicle travel time and reliability for freight movements within each segment. The proposed methodology has been used successfully to identify distinct segments and characteristics of travel time reliability in freight corridors. Travel time information was used to compute cost effects of delays within rural and urban areas along the I-5 corridor. The research presents an advance in the processing and aggregation of Global Positioning System truck data to produce succinct yet informative performance measures and segments. For more information: http://archives.pdx.edu/ds/psu/11487 Title: Algorithms for Studying the Impact of Travel Time Reliability Along Multisegment Trucking Freight Corridors Author: Figliozzi, Miguel, Wheeler, Nikki, Albright, Eric, Walker, Lindsay, Sarkar, Shreemoyee, Rice, Danielle Year: 2011 Performance measures allow planners and engineers to monitor and evaluate transportation facilities or projects and to justify the allocation of funds among alternative transportation improvement options. To capture the impact of corridor congestion on freight vehicles, new tools and methodologies are developed to analyze data from commercial vehicles and produce performance measures such as travel time, speed, and travel time reliability. Because long freight corridors comprise segments with varying reliability characteristics, the objective was to develop a programming logic that would use available truck Global Positioning System data to (a) identify natural segments or regions in a corridor between urban centers, Interstate junctions, or rural areas and (b) estimate corridorwide impact of travel time unreliability. The case study presented investigates the I-5 corridor in Oregon. The research applies statistical techniques to compute vehicle travel time and reliability for freight movements within each segment. The proposed methodology has been used successfully to identify distinct segments and characteristics of travel time reliability in freight corridors. Travel time information was used to compute cost effects of delays within rural and urban areas along the I-5 corridor. The research presents an advance in the processing and aggregation of Global Positioning System truck data to produce succinct yet informative performance measures and segments. For more information: http://archives.pdx.edu/ds/psu/11487 Close

• 4. [Article] How to Estimate Pedestrian Demand

  There is growing support to improve the quality of the walking environment and make investments to promote pedestrian travel. Such efforts often require analytical non-motorized planning tools to estimate ...

  Citation × Citation Citation Abstract Copy Title: How to Estimate Pedestrian Demand Author: Clifton, Kelly, Singleton, Patrick Allen, Muhs, Christopher D., Schneider, Robert J. Year: 2015 There is growing support to improve the quality of the walking environment and make investments to promote pedestrian travel. Such efforts often require analytical non-motorized planning tools to estimate levels of pedestrian demand that are sensitive to environmental and demographic factors at an appropriate scale. Despite this interest and need, current forecasting tools, particularly regional travel demand models, often fall short. To address this gap, Oregon Metro and NITC researcher Kelly Clifton worked together to develop a pedestrian demand estimation tool. For generations, planners have been using statistical models to forecast travel demand, but these models have traditionally been auto-centered. The new tool will allow planners to allocate infrastructure based on pedestrian demand in the Portland, Oregon metropolitan area. The tool is also designed to be replicable, so that other metropolitan areas can adapt the model to begin estimating pedestrian demand in their cities. Title: How to Estimate Pedestrian Demand Author: Clifton, Kelly, Singleton, Patrick Allen, Muhs, Christopher D., Schneider, Robert J. Year: 2015 There is growing support to improve the quality of the walking environment and make investments to promote pedestrian travel. Such efforts often require analytical non-motorized planning tools to estimate levels of pedestrian demand that are sensitive to environmental and demographic factors at an appropriate scale. Despite this interest and need, current forecasting tools, particularly regional travel demand models, often fall short. To address this gap, Oregon Metro and NITC researcher Kelly Clifton worked together to develop a pedestrian demand estimation tool. For generations, planners have been using statistical models to forecast travel demand, but these models have traditionally been auto-centered. The new tool will allow planners to allocate infrastructure based on pedestrian demand in the Portland, Oregon metropolitan area. The tool is also designed to be replicable, so that other metropolitan areas can adapt the model to begin estimating pedestrian demand in their cities. Close

• 5. [Article] Enhancing Targeted Traffic Enforcement Efforts in Portland, Oregon

  Enforcement is a key component of any comprehensive traffic safety program, and through a unique effort the Portland Office of Transportation (PDOT) partners with schools, the court system, community groups ...

  Citation × Citation Citation Abstract Copy Title: Enhancing Targeted Traffic Enforcement Efforts in Portland, Oregon Author: Coffman, Max, Monsere, Christopher Year: 2006 Enforcement is a key component of any comprehensive traffic safety program, and through a unique effort the Portland Office of Transportation (PDOT) partners with schools, the court system, community groups and the Police Bureau to develop a coordinated citywide program to improve traffic safety. However, like many government agencies, the Police Bureau faces constraints that limit the resources it can devote to traffic safety. In response, PDOT and the Police Bureau’s Traffic Division have instituted a program of Strategic and Focused Enforcement (SAFE) to better allocate limited traffic safety personnel and resources. Using historical crash data, PDOT identified 30 high crash corridors and the Police Bureau directed enforcement to these areas. This paper explores alternative techniques to identify SAFE corridors using more recent crash and driver error data. It also highlights the potential for the city to carry this program through to a more robust, high-profile implementation phase, and the new data analysis options that will become available in the next few years. This study will be useful for other practitioners wishing to engage enforcement as a key ally in improving traffic safety. Title: Enhancing Targeted Traffic Enforcement Efforts in Portland, Oregon Author: Coffman, Max, Monsere, Christopher Year: 2006 Enforcement is a key component of any comprehensive traffic safety program, and through a unique effort the Portland Office of Transportation (PDOT) partners with schools, the court system, community groups and the Police Bureau to develop a coordinated citywide program to improve traffic safety. However, like many government agencies, the Police Bureau faces constraints that limit the resources it can devote to traffic safety. In response, PDOT and the Police Bureau’s Traffic Division have instituted a program of Strategic and Focused Enforcement (SAFE) to better allocate limited traffic safety personnel and resources. Using historical crash data, PDOT identified 30 high crash corridors and the Police Bureau directed enforcement to these areas. This paper explores alternative techniques to identify SAFE corridors using more recent crash and driver error data. It also highlights the potential for the city to carry this program through to a more robust, high-profile implementation phase, and the new data analysis options that will become available in the next few years. This study will be useful for other practitioners wishing to engage enforcement as a key ally in improving traffic safety. Close

• 6. [Article] Empirical Analysis of Bus Bunching Characteristics Based on Bus AVL/APC Data

  Bus bunching takes place when headways between buses are irregular. Bus bunching is associated with longer waiting times for riders, overcrowding in some buses, and an overall decrease on the level of ...

  Citation × Citation Citation Abstract Copy Title: Empirical Analysis of Bus Bunching Characteristics Based on Bus AVL/APC Data Author: Feng, Wei, Figliozzi, Miguel A. Year: 2015 Bus bunching takes place when headways between buses are irregular. Bus bunching is associated with longer waiting times for riders, overcrowding in some buses, and an overall decrease on the level of service and capacity. Understanding the temporal and spatial characteristics and the causes and effects of bus bunching incidents from archived bus data can greatly aid transit agencies to develop efficient mitigation strategies. This paper presents methods to identify and visualize specific time periods and segments where bus bunching incidents occur based on automatic vehicle location (AVL) and automatic passenger count (APC) data. The paper also proposes methods that help analyze the causes and effects of bus bunching based on AVL/APC data. Temporal and spatial distributions of bus bunching events indicate high concentration during high frequency service hours and segments, and increasing concentration toward downstream. Time point bus stops can help reduce bus headway variability but with limited capability. Results indicate that irregular departure headway at the initial stop is the key cause of bus bunching rather than downstream traffic conditions and passenger demand uncertainty. A bus departure headway control at the initial stop of high frequency service zone is highly recommended, and a switch from schedule-based control to headway-based control strategy at time point stops in high frequency service zone is suggested. Title: Empirical Analysis of Bus Bunching Characteristics Based on Bus AVL/APC Data Author: Feng, Wei, Figliozzi, Miguel A. Year: 2015 Bus bunching takes place when headways between buses are irregular. Bus bunching is associated with longer waiting times for riders, overcrowding in some buses, and an overall decrease on the level of service and capacity. Understanding the temporal and spatial characteristics and the causes and effects of bus bunching incidents from archived bus data can greatly aid transit agencies to develop efficient mitigation strategies. This paper presents methods to identify and visualize specific time periods and segments where bus bunching incidents occur based on automatic vehicle location (AVL) and automatic passenger count (APC) data. The paper also proposes methods that help analyze the causes and effects of bus bunching based on AVL/APC data. Temporal and spatial distributions of bus bunching events indicate high concentration during high frequency service hours and segments, and increasing concentration toward downstream. Time point bus stops can help reduce bus headway variability but with limited capability. Results indicate that irregular departure headway at the initial stop is the key cause of bus bunching rather than downstream traffic conditions and passenger demand uncertainty. A bus departure headway control at the initial stop of high frequency service zone is highly recommended, and a switch from schedule-based control to headway-based control strategy at time point stops in high frequency service zone is suggested. Close

• 7. [Article] Exploring Thresholds for Timing Strategies on a Pedestrian Active Corridor

  Traditional signal timing policies have typically prioritized vehicles over pedestrians at intersections, leading to undesirable consequences such as large delays and risky crossing behaviors. The objective ...

  Citation × Citation Citation Abstract Copy Title: Exploring Thresholds for Timing Strategies on a Pedestrian Active Corridor Author: Kothuri, Sirisha Murthy, Koonce, Peter, Monsere, Christopher M., Reynolds, Titus Year: 2015 Traditional signal timing policies have typically prioritized vehicles over pedestrians at intersections, leading to undesirable consequences such as large delays and risky crossing behaviors. The objective of this paper is to explore signal timing control strategies to reduce pedestrian delay at signalized intersections. The impacts of change in signal controller mode of operation (coordinated vs. free) at intersections were studied using the micro-simulation software VISSIM. A base model was developed and calibrated for an existing pedestrian active corridor. A hypothetical network of three intersections was used to explore the effects of mode of operation and measures of delay for pedestrians and all users. From a pedestrian perspective, free operation was found to be more beneficial due to lower delays. However, from a system wide (all user) perspective, coordinated operation showed the greatest benefits with lowest system delay under heavy traffic conditions (v/c > 0.7). In the off-peak conditions when traffic volumes are lower, free operation resulted in lowest system delay (v/c < 0.7). During coordination, lower cycle lengths were beneficial for pedestrians, due to smaller delays. The results revealed that volume to capacity (v/c) ratios for the major street volumes coupled with pedestrian actuation frequency for the side street phases, could be used to determine the signal controller mode of operation that produces the lowest system delay. The results were used to create a guidance matrix for controller mode based on pedestrian and vehicle volumes. To demonstrate application, the matrix is applied to another corridor in a case study approach. Title: Exploring Thresholds for Timing Strategies on a Pedestrian Active Corridor Author: Kothuri, Sirisha Murthy, Koonce, Peter, Monsere, Christopher M., Reynolds, Titus Year: 2015 Traditional signal timing policies have typically prioritized vehicles over pedestrians at intersections, leading to undesirable consequences such as large delays and risky crossing behaviors. The objective of this paper is to explore signal timing control strategies to reduce pedestrian delay at signalized intersections. The impacts of change in signal controller mode of operation (coordinated vs. free) at intersections were studied using the micro-simulation software VISSIM. A base model was developed and calibrated for an existing pedestrian active corridor. A hypothetical network of three intersections was used to explore the effects of mode of operation and measures of delay for pedestrians and all users. From a pedestrian perspective, free operation was found to be more beneficial due to lower delays. However, from a system wide (all user) perspective, coordinated operation showed the greatest benefits with lowest system delay under heavy traffic conditions (v/c > 0.7). In the off-peak conditions when traffic volumes are lower, free operation resulted in lowest system delay (v/c < 0.7). During coordination, lower cycle lengths were beneficial for pedestrians, due to smaller delays. The results revealed that volume to capacity (v/c) ratios for the major street volumes coupled with pedestrian actuation frequency for the side street phases, could be used to determine the signal controller mode of operation that produces the lowest system delay. The results were used to create a guidance matrix for controller mode based on pedestrian and vehicle volumes. To demonstrate application, the matrix is applied to another corridor in a case study approach. Close

• 8. [Article] Development of a Pedestrian Demand Estimation Tool

  Most research on walking behavior has focused on mode choice or walk-trip frequency. In contrast, this study is one of the first to analyze the destination choice behaviors of pedestrians. Using about ...

  Citation × Citation Citation Abstract Copy Title: Development of a Pedestrian Demand Estimation Tool Author: Clifton, Kelly, Singleton, Patrick Allen, Muhs, Christopher D., Schneider, Robert J. Year: 2015 Most research on walking behavior has focused on mode choice or walk-trip frequency. In contrast, this study is one of the first to analyze the destination choice behaviors of pedestrians. Using about 4,500 walk trips from a 2011 household travel survey in the Portland, OR, region, we estimated multinomial logit pedestrian destination choice models for six trip purposes. Independent variables included terms for impedance (walk-trip distance); size (employment by type, households); supportive pedestrian environments (parks, a pedestrian index of the environment variable called PIE); barriers to walking (terrain, industrial-type employment); and traveler characteristics. Unique to this study was the use of small-scale destination zone alternatives. Distance was a significant deterrent to pedestrian destination choice, and people in carless or childless households were less sensitive to distance for some purposes. Employment (especially retail) was a strong attractor: doubling the number of jobs nearly doubled the odds of choosing a destination for home-based shopping walk trips. More attractive pedestrian environments were also positively associated with pedestrian destination choice after controlling for other factors. These results shed light on determinants of pedestrian destination choice behavior, and sensitivities in the models highlight potential policy-levers to increase walking activity. In addition, the destination choice models can be used in regional travel demand models or as pedestrian planning tools to evaluate land use and transportation policy and investment scenarios. Title: Development of a Pedestrian Demand Estimation Tool Author: Clifton, Kelly, Singleton, Patrick Allen, Muhs, Christopher D., Schneider, Robert J. Year: 2015 Most research on walking behavior has focused on mode choice or walk-trip frequency. In contrast, this study is one of the first to analyze the destination choice behaviors of pedestrians. Using about 4,500 walk trips from a 2011 household travel survey in the Portland, OR, region, we estimated multinomial logit pedestrian destination choice models for six trip purposes. Independent variables included terms for impedance (walk-trip distance); size (employment by type, households); supportive pedestrian environments (parks, a pedestrian index of the environment variable called PIE); barriers to walking (terrain, industrial-type employment); and traveler characteristics. Unique to this study was the use of small-scale destination zone alternatives. Distance was a significant deterrent to pedestrian destination choice, and people in carless or childless households were less sensitive to distance for some purposes. Employment (especially retail) was a strong attractor: doubling the number of jobs nearly doubled the odds of choosing a destination for home-based shopping walk trips. More attractive pedestrian environments were also positively associated with pedestrian destination choice after controlling for other factors. These results shed light on determinants of pedestrian destination choice behavior, and sensitivities in the models highlight potential policy-levers to increase walking activity. In addition, the destination choice models can be used in regional travel demand models or as pedestrian planning tools to evaluate land use and transportation policy and investment scenarios. Close