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• 1. [Article] The Role of Atmospheric Circulation Patterns in Agroclimate Variability in Finland, 1961-2011

  This study evaluates interannual variations and trends in growing season daily temperature sum and daily precipitation sum in Finland during 1961–2011, and their connections to well known atmospheric circulation ...

  Citation × Citation Citation Abstract Copy Title: The Role of Atmospheric Circulation Patterns in Agroclimate Variability in Finland, 1961-2011 Author: Irannezhad, Masoud, Chen, Deliang, Kløve, Bjørn Year: 2016 This study evaluates interannual variations and trends in growing season daily temperature sum and daily precipitation sum in Finland during 1961–2011, and their connections to well known atmospheric circulation patterns. Changes in summer (June–August) climate partially explain changes in growing season daily temperature sum and daily precipitation sum over Finland, which naturally decreased from south to north. On a national scale, growing season warmed and became wetter during 1961–2011, as growing season daily temperature sum and daily precipitation sum significantly (p < 0.05) increased by 5.01 ± 3.17°C year–1 and 1.39 ± 0.91 mm year–1, respectively. The East Atlantic pattern was the most influential atmospheric circulation pattern for variations in growing season daily temperature sum (rho = 0.40) across Finland and the East Atlantic/West Russia pattern was most influential for growing season daily precipitation sum variability (rho = –0.54). There were significant (p < 0.05) increasing trends in growing season daily temperature sum and daily precipitation sum throughout Finland during 1961–2011. Increased growing season daily temperature sum was mainly observed in northern, central, western, eastern and coastal areas of south-western Finland. This warming was positively associated with the East Atlantic pattern in the north, centre and south, but negatively associated with the East Atlantic/West Russia pattern in eastern Finland. Increased GSP mostly occurred in southern, eastern, western, central, northern and north-western Finland. These wetting trends were positively correlated with the East Atlantic pattern in the north and negatively correlated with the Polar pattern in the south and the East Atlantic/West Russia pattern in the east, west, centre and north-east of Finland. The overall agroclimatic year-to-year variability in Finland between 1961 and 2011 was mostly linked to variations in the East Atlantic and East Atlantic/West Russia patterns. Title: The Role of Atmospheric Circulation Patterns in Agroclimate Variability in Finland, 1961-2011 Author: Irannezhad, Masoud, Chen, Deliang, Kløve, Bjørn Year: 2016 This study evaluates interannual variations and trends in growing season daily temperature sum and daily precipitation sum in Finland during 1961–2011, and their connections to well known atmospheric circulation patterns. Changes in summer (June–August) climate partially explain changes in growing season daily temperature sum and daily precipitation sum over Finland, which naturally decreased from south to north. On a national scale, growing season warmed and became wetter during 1961–2011, as growing season daily temperature sum and daily precipitation sum significantly (p < 0.05) increased by 5.01 ± 3.17°C year–1 and 1.39 ± 0.91 mm year–1, respectively. The East Atlantic pattern was the most influential atmospheric circulation pattern for variations in growing season daily temperature sum (rho = 0.40) across Finland and the East Atlantic/West Russia pattern was most influential for growing season daily precipitation sum variability (rho = –0.54). There were significant (p < 0.05) increasing trends in growing season daily temperature sum and daily precipitation sum throughout Finland during 1961–2011. Increased growing season daily temperature sum was mainly observed in northern, central, western, eastern and coastal areas of south-western Finland. This warming was positively associated with the East Atlantic pattern in the north, centre and south, but negatively associated with the East Atlantic/West Russia pattern in eastern Finland. Increased GSP mostly occurred in southern, eastern, western, central, northern and north-western Finland. These wetting trends were positively correlated with the East Atlantic pattern in the north and negatively correlated with the Polar pattern in the south and the East Atlantic/West Russia pattern in the east, west, centre and north-east of Finland. The overall agroclimatic year-to-year variability in Finland between 1961 and 2011 was mostly linked to variations in the East Atlantic and East Atlantic/West Russia patterns. Close

• 2. [Article] Century-Long Variability and Trends in Daily Precipitation Characteristics at Three Finnish Stations

  Long-term variations and trends in a wide range of statistics for daily precipitation characteristics in terms of intensity, frequency and duration in Finland were analysed using precipitation records ...

  Citation × Citation Citation Abstract Copy Title: Century-Long Variability and Trends in Daily Precipitation Characteristics at Three Finnish Stations Author: Irannezhad, Masoud, Marttila, Hannu, De-liang, Chen, Kløve, Bjørn Year: 2016 Long-term variations and trends in a wide range of statistics for daily precipitation characteristics in terms of intensity, frequency and duration in Finland were analysed using precipitation records during 1908－2008 from 3 meteorological stations in the south (Kaisaniemi), center (Kajaani) and north (Sodankylä). Although precipitation days in northern part were more frequent than in central and southern parts, daily precipitation intensity in the south was generally higher than those in the centre and north of the country. Annual sum of very light precipitation (0 mm < daily precipitation ≤ long-term 50th percentile of daily precipitation more than 0 mm) significantly (p Title: Century-Long Variability and Trends in Daily Precipitation Characteristics at Three Finnish Stations Author: Irannezhad, Masoud, Marttila, Hannu, De-liang, Chen, Kløve, Bjørn Year: 2016 Long-term variations and trends in a wide range of statistics for daily precipitation characteristics in terms of intensity, frequency and duration in Finland were analysed using precipitation records during 1908－2008 from 3 meteorological stations in the south (Kaisaniemi), center (Kajaani) and north (Sodankylä). Although precipitation days in northern part were more frequent than in central and southern parts, daily precipitation intensity in the south was generally higher than those in the centre and north of the country. Annual sum of very light precipitation (0 mm < daily precipitation ≤ long-term 50th percentile of daily precipitation more than 0 mm) significantly (p Close

• 3. [Article] Archival Water-Level Measurements: Recovering Historical Data to Help Design for the Future

  Improving methods of assessing risk and designing structures to withstand extreme events and changing sea levels is a vital component of strategies for reducing risk to coastal resources and assets. An ...

  Citation × Citation Citation Abstract Copy Title: Archival Water-Level Measurements: Recovering Historical Data to Help Design for the Future Author: Talke, Stefan A., Jay, David A. Year: 2017 Improving methods of assessing risk and designing structures to withstand extreme events and changing sea levels is a vital component of strategies for reducing risk to coastal resources and assets. An obvious approach to improving the statistical robustness of risk assessments is to increase the number, time span, and quality of available water-level data sets, and to assess trends and non-stationarity. In this report we discuss efforts to recover, digitize, and analyze hundreds of station-years of lost-and-forgotten tide data and other water-level measurements that extend back to the early 19th century. To date, more than 6,500 station-years of previously lost or forgotten tide data have been identified, of which more than 1,600 station-years have been recovered and more than 550 station-years digitized. An additional 500+ years of once-a-day river-stage measurements in tidal rivers have been recovered and digitized. Approximately 300,000 documents have been recovered. In this report we also demonstrate how data recovery can help engineers better characterize their water-level environment and understand long-term trends, resulting in better risk assessment and ultimately more robust design of new infrastructure and adaptation of existing infrastructure. Long records help improve hazard estimates and can help characterize whether statistics are nonstationarity over climate-relevant time scales. Further, long and more complete records exhibit more natural variability and can be used to validate numerical simulations of historical storms (e.g., the 1893 New York hurricane). Historical tide data can help inform how tidal datums such as High Water and Low Water have changed, can be used to hindcast historical river flow, and provide a much richer view of long-term trends in local sea level. Used with numerical models, historical data help explain how anthropogenic activities have changed tide range and river slope, with the largest effects often observed far inland from the coast. Moreover, numerical models combined with tide data can be used to assess whether local engineering or other long-term changes have influenced storm surge risk. In conclusion, improved assessment of the past can help us better plan for the future. Title: Archival Water-Level Measurements: Recovering Historical Data to Help Design for the Future Author: Talke, Stefan A., Jay, David A. Year: 2017 Improving methods of assessing risk and designing structures to withstand extreme events and changing sea levels is a vital component of strategies for reducing risk to coastal resources and assets. An obvious approach to improving the statistical robustness of risk assessments is to increase the number, time span, and quality of available water-level data sets, and to assess trends and non-stationarity. In this report we discuss efforts to recover, digitize, and analyze hundreds of station-years of lost-and-forgotten tide data and other water-level measurements that extend back to the early 19th century. To date, more than 6,500 station-years of previously lost or forgotten tide data have been identified, of which more than 1,600 station-years have been recovered and more than 550 station-years digitized. An additional 500+ years of once-a-day river-stage measurements in tidal rivers have been recovered and digitized. Approximately 300,000 documents have been recovered. In this report we also demonstrate how data recovery can help engineers better characterize their water-level environment and understand long-term trends, resulting in better risk assessment and ultimately more robust design of new infrastructure and adaptation of existing infrastructure. Long records help improve hazard estimates and can help characterize whether statistics are nonstationarity over climate-relevant time scales. Further, long and more complete records exhibit more natural variability and can be used to validate numerical simulations of historical storms (e.g., the 1893 New York hurricane). Historical tide data can help inform how tidal datums such as High Water and Low Water have changed, can be used to hindcast historical river flow, and provide a much richer view of long-term trends in local sea level. Used with numerical models, historical data help explain how anthropogenic activities have changed tide range and river slope, with the largest effects often observed far inland from the coast. Moreover, numerical models combined with tide data can be used to assess whether local engineering or other long-term changes have influenced storm surge risk. In conclusion, improved assessment of the past can help us better plan for the future. Close

• 4. [Article] Increasing Storm Tides in New York Harbor, 1844–2013

  Three of the nine highest recorded water levels in the New York Harbor region have occurred since 2010 (March 2010, August 2011, and October 2012), and eight of the largest twenty have occurred since 1990. ...

  Citation × Citation Citation Abstract Copy Title: Increasing Storm Tides in New York Harbor, 1844–2013 Author: Talke, Stefan A., Orton, Philip M., Jay, David A. Year: 2014 Three of the nine highest recorded water levels in the New York Harbor region have occurred since 2010 (March 2010, August 2011, and October 2012), and eight of the largest twenty have occurred since 1990. To investigate whether this cluster of high waters is a random occurrence or indicative of intensified storm tides, we recover archival tide gauge data back to 1844 and evaluate the trajectory of the annual maximum storm tide. Approximately half of long-term variance is anticorrelated with decadal-scale variations in the North Atlantic Oscillation, while long-term trends explain the remainder. The 10 year storm tide has increased by 0.28 m. Combined with a 0.44 m increase in local sea level since 1856, the 10 year flood level has increased by approximately 0.72 ± 0.25 m, and magnified the annual probability of overtopping the typical Manhattan seawall from less than 1% to about 20–25%. Title: Increasing Storm Tides in New York Harbor, 1844–2013 Author: Talke, Stefan A., Orton, Philip M., Jay, David A. Year: 2014 Three of the nine highest recorded water levels in the New York Harbor region have occurred since 2010 (March 2010, August 2011, and October 2012), and eight of the largest twenty have occurred since 1990. To investigate whether this cluster of high waters is a random occurrence or indicative of intensified storm tides, we recover archival tide gauge data back to 1844 and evaluate the trajectory of the annual maximum storm tide. Approximately half of long-term variance is anticorrelated with decadal-scale variations in the North Atlantic Oscillation, while long-term trends explain the remainder. The 10 year storm tide has increased by 0.28 m. Combined with a 0.44 m increase in local sea level since 1856, the 10 year flood level has increased by approximately 0.72 ± 0.25 m, and magnified the annual probability of overtopping the typical Manhattan seawall from less than 1% to about 20–25%. Close

• 5. [Article] Geostatistical Examination of the Geotechnical Portland BES Databases with Emphasis on Silt

  Willamette Valley silt deposits from historical catastrophic flood events present a difficult problem for subsurface engineers practicing in the Portland, Oregon area. Silts exhibit behavior of two very ...

  Citation × Citation Citation Abstract Copy Title: Geostatistical Examination of the Geotechnical Portland BES Databases with Emphasis on Silt Author: Baumann, Alex K. Year: 2015 Willamette Valley silt deposits from historical catastrophic flood events present a difficult problem for subsurface engineers practicing in the Portland, Oregon area. Silts exhibit behavior of two very well-documented soil types, but publications containing mechanical properties for silts are scant, especially for local silts. Thus, the need for links between real Portland site investigation data and silt properties is high. To further exemplify the need for documented knowledge of local silts, this project reveals the evolving state of practice to incorporate more Pacific Northwest seismic analyses in preparation for a subduction zone earthquake. The geotechnical Portland BES databases contain thousands of private sector (PrS) and public sector (PbS) geotechnical documents from sites in the Portland area. The PrS database includes approximately 7,000 geotechnical documents for PrS projects dating primarily from the mid 1900’s to 2009 for a range of project types. A statistically significant random sample of 1,500 documents from the PrS database was organized and analyzed. The approximate 1,000 documents in the PbS database containing boring logs can be linked to location through a pre-existing GIS layer. The statistically significant sample from the PrS database and the GIS layer from the PbS database were compared spatially to reveal clusters of documented geotechnical projects. An isolated cluster of 80 full geotechnical reports in the Downtown, Portland area from reputable practitioners was examined for standard penetration blow counts, equipment information, groundwater table depths, soil descriptions, unit weights, drill dates, and moisture contents to capture a range of correlated peak effective friction angles for different compositions of silt. The project types and report contents from the PrS database were analyzed in the Downtown area, and conclusions were made on the percentages of project types and apparent chronological trends in report content. Title: Geostatistical Examination of the Geotechnical Portland BES Databases with Emphasis on Silt Author: Baumann, Alex K. Year: 2015 Willamette Valley silt deposits from historical catastrophic flood events present a difficult problem for subsurface engineers practicing in the Portland, Oregon area. Silts exhibit behavior of two very well-documented soil types, but publications containing mechanical properties for silts are scant, especially for local silts. Thus, the need for links between real Portland site investigation data and silt properties is high. To further exemplify the need for documented knowledge of local silts, this project reveals the evolving state of practice to incorporate more Pacific Northwest seismic analyses in preparation for a subduction zone earthquake. The geotechnical Portland BES databases contain thousands of private sector (PrS) and public sector (PbS) geotechnical documents from sites in the Portland area. The PrS database includes approximately 7,000 geotechnical documents for PrS projects dating primarily from the mid 1900’s to 2009 for a range of project types. A statistically significant random sample of 1,500 documents from the PrS database was organized and analyzed. The approximate 1,000 documents in the PbS database containing boring logs can be linked to location through a pre-existing GIS layer. The statistically significant sample from the PrS database and the GIS layer from the PbS database were compared spatially to reveal clusters of documented geotechnical projects. An isolated cluster of 80 full geotechnical reports in the Downtown, Portland area from reputable practitioners was examined for standard penetration blow counts, equipment information, groundwater table depths, soil descriptions, unit weights, drill dates, and moisture contents to capture a range of correlated peak effective friction angles for different compositions of silt. The project types and report contents from the PrS database were analyzed in the Downtown area, and conclusions were made on the percentages of project types and apparent chronological trends in report content. Close

• 6. [Article] Exploring Pedestrian Responsive Traffic Signal Timing Strategies in Urban Areas

  The role of walking in the development of healthy, livable communities is being increasingly recognized. In urban areas, intersections represent locations where different modes converge, and are often ...

  Citation × Citation Citation Abstract Copy Title: Exploring Pedestrian Responsive Traffic Signal Timing Strategies in Urban Areas Author: Kothuri, Sirisha Murthy Year: 2014 The role of walking in the development of healthy, livable communities is being increasingly recognized. In urban areas, intersections represent locations where different modes converge, and are often viewed as deterrents to walking. This is due to the unwarranted and often unnecessary delays imposed by signal timing policies for pedestrians and increased potential for conflicts. Traditional signal timing design prioritizes vehicles over pedestrians leading to undesirable consequences such as large delays and risky pedestrian behaviors. Pedestrians are accommodated in a manner that is designed to cause least interruption to the flow of motor vehicles. This lack of pedestrian accommodation at signalized intersections is the focus of this dissertation. Understanding pedestrian attitudes and perceptions is important because it offers insights into actual crossing behavior at signalized intersections. An intercept survey of 367 crossing pedestrians was undertaken at four signalized intersections in Portland, Oregon, and binary logistic regression models were constructed to quantify the impacts of demographics, trip characteristics and type of infrastructure on pedestrian perceptions and attitudes regarding delay, crossing time and motivators for crossing decisions. Safety was found to have a larger effect than compliance on the decision to cross the street. Pedestrians at recall intersections expressed higher satisfaction with delay than at actuated intersections. Novel methods to measure pedestrian delay using 2070 signal controllers and Voyage software were developed. These methods have been adopted by the City of Portland to record actuation trends and delays at various intersections. In the absence of demand data, pedestrian push button actuations can be considered as a proxy for crossing demand. The micro-simulation software VISSIM was used to analyze delays resulting from varying pedestrian and vehicle volumes on a network of three intersections in Portland, Oregon. From a pedestrian perspective, free operation was found to be always beneficial due to lower pedestrian delays. However, from a system wide perspective, free operation was found to be beneficial only under low-medium traffic conditions from an overall delay reduction viewpoint, while coordinated operation showed benefits under heavy traffic conditions, irrespective of the volume of pedestrians. Control strategies were developed to identify the best mode of signal controller operation that produced the lowest overall average delay per user. A procedure to identify the optimal control strategy based on user inputs (major street volume to capacity ratios and rate of pedestrian phase serviced for the minor street) was developed. The procedure was applied to a network of three intersections in east Portland, OR and the findings were verified. This research offers significant contributions in the field of pedestrian research. The findings related to attitudes and perceptions of crossing pedestrians offer greater insights into pedestrian crossing behavior and add to the body of existing literature. The methods developed to obtain pedestrian actuations and delay data from signal controllers represent an easy and cost-effective way to characterize pedestrian service at intersections. The results pertaining to signal timing strategies represent an important step towards incorporating pedestrian needs at intersections and demonstrate how control strategies employed to benefit pedestrians could benefit the entire system. Title: Exploring Pedestrian Responsive Traffic Signal Timing Strategies in Urban Areas Author: Kothuri, Sirisha Murthy Year: 2014 The role of walking in the development of healthy, livable communities is being increasingly recognized. In urban areas, intersections represent locations where different modes converge, and are often viewed as deterrents to walking. This is due to the unwarranted and often unnecessary delays imposed by signal timing policies for pedestrians and increased potential for conflicts. Traditional signal timing design prioritizes vehicles over pedestrians leading to undesirable consequences such as large delays and risky pedestrian behaviors. Pedestrians are accommodated in a manner that is designed to cause least interruption to the flow of motor vehicles. This lack of pedestrian accommodation at signalized intersections is the focus of this dissertation. Understanding pedestrian attitudes and perceptions is important because it offers insights into actual crossing behavior at signalized intersections. An intercept survey of 367 crossing pedestrians was undertaken at four signalized intersections in Portland, Oregon, and binary logistic regression models were constructed to quantify the impacts of demographics, trip characteristics and type of infrastructure on pedestrian perceptions and attitudes regarding delay, crossing time and motivators for crossing decisions. Safety was found to have a larger effect than compliance on the decision to cross the street. Pedestrians at recall intersections expressed higher satisfaction with delay than at actuated intersections. Novel methods to measure pedestrian delay using 2070 signal controllers and Voyage software were developed. These methods have been adopted by the City of Portland to record actuation trends and delays at various intersections. In the absence of demand data, pedestrian push button actuations can be considered as a proxy for crossing demand. The micro-simulation software VISSIM was used to analyze delays resulting from varying pedestrian and vehicle volumes on a network of three intersections in Portland, Oregon. From a pedestrian perspective, free operation was found to be always beneficial due to lower pedestrian delays. However, from a system wide perspective, free operation was found to be beneficial only under low-medium traffic conditions from an overall delay reduction viewpoint, while coordinated operation showed benefits under heavy traffic conditions, irrespective of the volume of pedestrians. Control strategies were developed to identify the best mode of signal controller operation that produced the lowest overall average delay per user. A procedure to identify the optimal control strategy based on user inputs (major street volume to capacity ratios and rate of pedestrian phase serviced for the minor street) was developed. The procedure was applied to a network of three intersections in east Portland, OR and the findings were verified. This research offers significant contributions in the field of pedestrian research. The findings related to attitudes and perceptions of crossing pedestrians offer greater insights into pedestrian crossing behavior and add to the body of existing literature. The methods developed to obtain pedestrian actuations and delay data from signal controllers represent an easy and cost-effective way to characterize pedestrian service at intersections. The results pertaining to signal timing strategies represent an important step towards incorporating pedestrian needs at intersections and demonstrate how control strategies employed to benefit pedestrians could benefit the entire system. Close

• 7. [Article] Safety at Intersections in Oregon – A Preliminary Update of Statewide Intersection Crash Rates

  This research aims to provide a preliminary update to statewide intersection crash rates for the state of Oregon using 2008-2013 crash data and a statewide sample of 129 intersections where two (or more) ...

  Citation × Citation Citation Abstract Copy Title: Safety at Intersections in Oregon – A Preliminary Update of Statewide Intersection Crash Rates Author: Hazel, Daniel R. Year: 2015 This research aims to provide a preliminary update to statewide intersection crash rates for the state of Oregon using 2008-2013 crash data and a statewide sample of 129 intersections where two (or more) state-owned facilities intersect. Using intersections where state-owned facilities represent both the major and minor legs of the intersection allows for the maintenance of up-to-date intersection crash rates by eliminating time-intensive traffic volume data collection. Due to the frequency and severity of crashes at intersections, development of easily obtained intersection crash rates is important to assess trends and effectiveness of safety countermeasures employed at these locations in the current data year as well as over longer analysis periods. This research also evaluates whether a recent crash report processing change within the Crash Analysis Reporting Unit of the Oregon Department of Transportation significantly increased intersection crash rates after the year 2011. As part of a special request, this research also provides fatal and incapacitating injury crash rates for a statewide sample of 500 intersections, calculated from 2003-2007 crash data. Intersection crash rates were calculated for each of three analysis periods: 2003-2007, 2008-2010, and 2011-2013. The calculated rates were compared using statistical tests to determine if the statewide intersection crash rates had changed over time. The objective of this analysis was to detect if, over time intersection crash rates in the state of Oregon had changed significantly. Crash rates were calculated based on 2,731 crashes that were extracted from a sample of 129 intersections over an 11-year period. To evaluate if changes that occurred with regard to crash reporting procedures within the Crash Analysis Reporting Unit manifested themselves in crash rates, statistical tests were completed to assess the rates for the analysis periods 2008-2010 and 2011-2013. The procedural change allowed approximately 5,000 additional non-fatal crashes to be added to the yearly crash database beginning in the year 2011. Fatal and incapacitating injury crash rates were calculated using 2003-2007 crash data for a statewide sample of 500 intersections. The Transportation Planning Analysis Unit of the Oregon Department of Transportation will use the calculated rates to flag intersections within Oregon for further safety analysis provided the crash rate at the intersection exceeds the mean or 90th percentile statewide crash rate. Preliminary results suggest that a larger sample of intersections is required in order to provide statistically representative results. Crash rates calculated from a sample made up of only intersections where two (or more) state-owned facilities intersect did not compare to a statewide sample of intersections with facilities owned by multiple jurisdictions. Due to the limited sample size, only three of the eight intersection groups were analyzed throughout the entirety of this research. The three intersection groups analyzed were rural 3-leg stop controlled (R3ST), rural 4-leg stop controlled (R4ST), and urban 4-leg signalized (U4SG) intersections. Results for the comparison of crash rate over time show that insufficient data were available to prove evidence of significant differences in crash rates. Larger sample sizes are required to determine if intersection crash rates in the state of Oregon have changed significantly over time. Statistically significant results were revealed for R4ST and U4SG intersection groups, highlighting the affects of the internal crash report processing change that occurred in the year 2011. The results showed that significant increases in mean crash rates were evident when comparing the two analysis periods. More data are required to determine if the results obtained in this preliminary analysis are cohesive in nature, spreading across all or the majority of intersection types. Due to limited comparison data for the calculated fatal and incapacitating injury intersection crash rates for the state of Oregon, a comprehensive analysis of the resulting crash rates was not provided. The result of the calculated rates do show that on average, urban crash rates were 1.47 times greater than rural rates. Only one rural intersection group (R4ST) had fatal and incapacitating injury crash rates greater than its urban counterpart group (U4ST). The crash rates for the two intersection groups R4ST and U4ST were 3.661 and 0.321 (reported in crashes per 100 million entering vehicles), respectively. Title: Safety at Intersections in Oregon – A Preliminary Update of Statewide Intersection Crash Rates Author: Hazel, Daniel R. Year: 2015 This research aims to provide a preliminary update to statewide intersection crash rates for the state of Oregon using 2008-2013 crash data and a statewide sample of 129 intersections where two (or more) state-owned facilities intersect. Using intersections where state-owned facilities represent both the major and minor legs of the intersection allows for the maintenance of up-to-date intersection crash rates by eliminating time-intensive traffic volume data collection. Due to the frequency and severity of crashes at intersections, development of easily obtained intersection crash rates is important to assess trends and effectiveness of safety countermeasures employed at these locations in the current data year as well as over longer analysis periods. This research also evaluates whether a recent crash report processing change within the Crash Analysis Reporting Unit of the Oregon Department of Transportation significantly increased intersection crash rates after the year 2011. As part of a special request, this research also provides fatal and incapacitating injury crash rates for a statewide sample of 500 intersections, calculated from 2003-2007 crash data. Intersection crash rates were calculated for each of three analysis periods: 2003-2007, 2008-2010, and 2011-2013. The calculated rates were compared using statistical tests to determine if the statewide intersection crash rates had changed over time. The objective of this analysis was to detect if, over time intersection crash rates in the state of Oregon had changed significantly. Crash rates were calculated based on 2,731 crashes that were extracted from a sample of 129 intersections over an 11-year period. To evaluate if changes that occurred with regard to crash reporting procedures within the Crash Analysis Reporting Unit manifested themselves in crash rates, statistical tests were completed to assess the rates for the analysis periods 2008-2010 and 2011-2013. The procedural change allowed approximately 5,000 additional non-fatal crashes to be added to the yearly crash database beginning in the year 2011. Fatal and incapacitating injury crash rates were calculated using 2003-2007 crash data for a statewide sample of 500 intersections. The Transportation Planning Analysis Unit of the Oregon Department of Transportation will use the calculated rates to flag intersections within Oregon for further safety analysis provided the crash rate at the intersection exceeds the mean or 90th percentile statewide crash rate. Preliminary results suggest that a larger sample of intersections is required in order to provide statistically representative results. Crash rates calculated from a sample made up of only intersections where two (or more) state-owned facilities intersect did not compare to a statewide sample of intersections with facilities owned by multiple jurisdictions. Due to the limited sample size, only three of the eight intersection groups were analyzed throughout the entirety of this research. The three intersection groups analyzed were rural 3-leg stop controlled (R3ST), rural 4-leg stop controlled (R4ST), and urban 4-leg signalized (U4SG) intersections. Results for the comparison of crash rate over time show that insufficient data were available to prove evidence of significant differences in crash rates. Larger sample sizes are required to determine if intersection crash rates in the state of Oregon have changed significantly over time. Statistically significant results were revealed for R4ST and U4SG intersection groups, highlighting the affects of the internal crash report processing change that occurred in the year 2011. The results showed that significant increases in mean crash rates were evident when comparing the two analysis periods. More data are required to determine if the results obtained in this preliminary analysis are cohesive in nature, spreading across all or the majority of intersection types. Due to limited comparison data for the calculated fatal and incapacitating injury intersection crash rates for the state of Oregon, a comprehensive analysis of the resulting crash rates was not provided. The result of the calculated rates do show that on average, urban crash rates were 1.47 times greater than rural rates. Only one rural intersection group (R4ST) had fatal and incapacitating injury crash rates greater than its urban counterpart group (U4ST). The crash rates for the two intersection groups R4ST and U4ST were 3.661 and 0.321 (reported in crashes per 100 million entering vehicles), respectively. Close