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• 1. [Article] Safety Effectiveness of Pedestrian Crossing Treatments

  Over the last decade, the transportation agencies in Oregon have systematically enhanced many pedestrian crossings at mid-block locations with Rectangular Rapid Flashing Beacons (RRFBs), Flashing Yellow ...

  Citation × Citation Citation Abstract Copy Title: Safety Effectiveness of Pedestrian Crossing Treatments Author: Monsere, Christopher Year: 2017 Over the last decade, the transportation agencies in Oregon have systematically enhanced many pedestrian crossings at mid-block locations with Rectangular Rapid Flashing Beacons (RRFBs), Flashing Yellow Beacons (Flash), and high visibility crosswalk markings (Hi-Vis). Enhancements often included the installation of refuge medians. This study explored the safety performance of these enhanced crossings, categorized by enhancement type. Data were collected on 191 crossings that included installation year, geometric features, surrounding land use, traffic volumes, and the number of crashes. Because pedestrian volume at the locations was unavailable, a pedestrian activity level variable was developed. Target crashes for analysis were identified as pedestrian and rear-end. The analysis of the before-after crash patterns showed a reduction in the pedestrian crash severity after the installation of the crosswalk enhancements. Risk ratios, calculated by the unadjusted crash frequency relative to the years of operation in each analysis category, were calculated. For pedestrian crashes, risk ratios increased with the number of lanes, posted speed, and estimated pedestrian activity level. Similar trends were observed for rear-end crashes. Due to sample size limitations, safety effectiveness was only estimated for the 19 RRFBs locations. Lack of pedestrian volumes limited the development of a safety performance function (SPF) for the pedestrian crash types. However, a rear-end crash SPF was estimated. Standard methods to estimate a crash modification factor (CMF) were attempted. The recommended CMF for pedestrian crashes is 0.64 +/- 0.26 using a simple before-after analysis and 0.93 +/- 0.22 for rear-end crashes using an empirical Bayes analysis. The final report that the presentation is derived from is available: https://doi.org/10.15760/trec.168 Title: Safety Effectiveness of Pedestrian Crossing Treatments Author: Monsere, Christopher Year: 2017 Over the last decade, the transportation agencies in Oregon have systematically enhanced many pedestrian crossings at mid-block locations with Rectangular Rapid Flashing Beacons (RRFBs), Flashing Yellow Beacons (Flash), and high visibility crosswalk markings (Hi-Vis). Enhancements often included the installation of refuge medians. This study explored the safety performance of these enhanced crossings, categorized by enhancement type. Data were collected on 191 crossings that included installation year, geometric features, surrounding land use, traffic volumes, and the number of crashes. Because pedestrian volume at the locations was unavailable, a pedestrian activity level variable was developed. Target crashes for analysis were identified as pedestrian and rear-end. The analysis of the before-after crash patterns showed a reduction in the pedestrian crash severity after the installation of the crosswalk enhancements. Risk ratios, calculated by the unadjusted crash frequency relative to the years of operation in each analysis category, were calculated. For pedestrian crashes, risk ratios increased with the number of lanes, posted speed, and estimated pedestrian activity level. Similar trends were observed for rear-end crashes. Due to sample size limitations, safety effectiveness was only estimated for the 19 RRFBs locations. Lack of pedestrian volumes limited the development of a safety performance function (SPF) for the pedestrian crash types. However, a rear-end crash SPF was estimated. Standard methods to estimate a crash modification factor (CMF) were attempted. The recommended CMF for pedestrian crashes is 0.64 +/- 0.26 using a simple before-after analysis and 0.93 +/- 0.22 for rear-end crashes using an empirical Bayes analysis. The final report that the presentation is derived from is available: https://doi.org/10.15760/trec.168 Close

• 2. [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

• 3. [Article] Assessment of Statewide Intersection Safety Performance

  This report summarizes the results of an analysis of the safety performance of Oregon’s intersections. Following a pilot study, a database of 500 intersections randomly sampled from around the state of ...

  Citation × Citation Citation Abstract Copy Title: Assessment of Statewide Intersection Safety Performance Author: Monsere, Christopher, Johnson, Todd, Dixon, Karen, Zheng, Jianfei, Schalkwyk, Ida Year: 2011 This report summarizes the results of an analysis of the safety performance of Oregon’s intersections. Following a pilot study, a database of 500 intersections randomly sampled from around the state of Oregon in both urban and rural environments was assembled. These intersections were categorized into eight types based on number of legs (3 and 4), land use (urban or rural) and traffic control (signalized or minor stop-control). These categories were chosen to align with the intersection types in AASHTO’s recently released Highway Safety Manual (HSM). Geometric and traffic control elements were supplemented by compiling crash data and volumes on the major and minor approaches. The safety performance was analyzed by three primary methods. First, crash rates were calculated and analyzed for each of the intersection groups. Crash rates determined for Oregon intersections were generally well below rates found published for other states. Since it is unlikely that such a significant difference exists in the safety performance between states, it is more likely explanation is the different reporting thresholds and Oregon’s reliance on self-reporting. Second, crash patterns were tabulated for a number of crash and driver involved variables. These patterns, not before generated, will be very useful to improve identification of high crash intersection locations and improve diagnosis of these locations. Third, safety performance functions (SPFs) were created for intersections where sufficient data exist. For the purposes of this research SPFs were estimated for the rural 3-leg stop controlled and urban 4-leg signalized intersections. The SPFs developed in this modeling exercise were compared to the HSM base models calibrated to Oregon. The rural 3-leg stop models compare favorably. Within the volume range of the data used to generate the SPFs, the models compare well. The urban signalized intersection SPFs did not compare as well to the HSM base models. Further research is needed to investigate whether Oregon-specific SPFs have advantages over calibrated HSM models. The results of this analysis can be used to improve the diagnosis and identification of unusual safety performance at intersections in Oregon. The average rates are useful for peer comparisons and in calculation of critical rates. The crash patterns can be directly applied in diagnostic efforts to detect unusual patterns at intersections. The SPF modeling effort is the groundwork for further explorations and model development for Oregon facilities. Title: Assessment of Statewide Intersection Safety Performance Author: Monsere, Christopher, Johnson, Todd, Dixon, Karen, Zheng, Jianfei, Schalkwyk, Ida Year: 2011 This report summarizes the results of an analysis of the safety performance of Oregon’s intersections. Following a pilot study, a database of 500 intersections randomly sampled from around the state of Oregon in both urban and rural environments was assembled. These intersections were categorized into eight types based on number of legs (3 and 4), land use (urban or rural) and traffic control (signalized or minor stop-control). These categories were chosen to align with the intersection types in AASHTO’s recently released Highway Safety Manual (HSM). Geometric and traffic control elements were supplemented by compiling crash data and volumes on the major and minor approaches. The safety performance was analyzed by three primary methods. First, crash rates were calculated and analyzed for each of the intersection groups. Crash rates determined for Oregon intersections were generally well below rates found published for other states. Since it is unlikely that such a significant difference exists in the safety performance between states, it is more likely explanation is the different reporting thresholds and Oregon’s reliance on self-reporting. Second, crash patterns were tabulated for a number of crash and driver involved variables. These patterns, not before generated, will be very useful to improve identification of high crash intersection locations and improve diagnosis of these locations. Third, safety performance functions (SPFs) were created for intersections where sufficient data exist. For the purposes of this research SPFs were estimated for the rural 3-leg stop controlled and urban 4-leg signalized intersections. The SPFs developed in this modeling exercise were compared to the HSM base models calibrated to Oregon. The rural 3-leg stop models compare favorably. Within the volume range of the data used to generate the SPFs, the models compare well. The urban signalized intersection SPFs did not compare as well to the HSM base models. Further research is needed to investigate whether Oregon-specific SPFs have advantages over calibrated HSM models. The results of this analysis can be used to improve the diagnosis and identification of unusual safety performance at intersections in Oregon. The average rates are useful for peer comparisons and in calculation of critical rates. The crash patterns can be directly applied in diagnostic efforts to detect unusual patterns at intersections. The SPF modeling effort is the groundwork for further explorations and model development for Oregon facilities. Close