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• 1. [Article] Analysis of Induced Travel in the 1995 NPTS

  In this paper we estimate the relationship between road capacity and vehicle miles of travel (VMT) from a sample of 12,000 respondents from 48 urban areas in the 1995 Nationwide Personal Transportation ...

  Citation × Citation Citation Abstract Copy Title: Analysis of Induced Travel in the 1995 NPTS Author: Strathman, James G., Dueker, Kenneth, Sanchez, Thomas W., Zhang, Jihong, Riis, Ann-Elizabeth Year: 2000 In this paper we estimate the relationship between road capacity and vehicle miles of travel (VMT) from a sample of 12,000 respondents from 48 urban areas in the 1995 Nationwide Personal Transportation Survey (NPTS). Our approach seeks to account for the effects of residential location, employment location, and commute mode choice in estimating the effect of capacity on VMT. VMT is found to be directly related to road capacity, as well as indirectly related through the influence of road capacity on residential and work place densities. Title: Analysis of Induced Travel in the 1995 NPTS Author: Strathman, James G., Dueker, Kenneth, Sanchez, Thomas W., Zhang, Jihong, Riis, Ann-Elizabeth Year: 2000 In this paper we estimate the relationship between road capacity and vehicle miles of travel (VMT) from a sample of 12,000 respondents from 48 urban areas in the 1995 Nationwide Personal Transportation Survey (NPTS). Our approach seeks to account for the effects of residential location, employment location, and commute mode choice in estimating the effect of capacity on VMT. VMT is found to be directly related to road capacity, as well as indirectly related through the influence of road capacity on residential and work place densities. Close

• 2. [Article] The Effects of Roadway Capacity on Peak Narrowing - Evidence from 1995 NPTS

  Spreading of the peak is one effect of increased peak-period congestion. Due to peak spreading, the travel-time impact of congestion is mitigated for some travelers, but the inconvenience of traveling ...

  Citation × Citation Citation Abstract Copy Title: The Effects of Roadway Capacity on Peak Narrowing - Evidence from 1995 NPTS Author: Zhang, Jihong, Rufolo, Anthony M., Dueker, Kenneth, Strathman, James G. Year: 2000 Spreading of the peak is one effect of increased peak-period congestion. Due to peak spreading, the travel-time impact of congestion is mitigated for some travelers, but the inconvenience of traveling at a less-preferred time also has a cost. Alternatively, increases in capacity have their impacts on peak-period congestion mitigated by a narrowing of the peak. This reduces the travel-time savings, but it generates a benefit for those traveling closer to their preferred times. This benefit from capacity improvements has largely been ignored, and one reason is the difficulty of quantifying the effect. This paper reports on some crude attempts to quantify the peak-narrowing effect of increased capacity. Using 1995 Nationwide Personal Transportation Survey (NPTS) data, this study investigates how workers in Metropolitan Statistical Areas (MSAs) in the US respond to roadway capacity differences in terms of changing their departure time to work. It is assumed that there is some distribution of travel times given by a mean and some measure of deviation from the mean. Peak narrowing is then measured by decreases in the deviation from the mean. The peak narrowing effects are modeled for both the morning commute and all departures from home for work at any time of the day. As expected, in urban areas with higher roadway capacity per capita, workers tend to depart from home closer to the peak time. For the morning commute, the model estimates that each one-percent increase in lane-miles per capita results in workers departing from home about 5.75 percent closer to the peak time. The effects of roadway capacity are found to be statistically significant in both models. Title: The Effects of Roadway Capacity on Peak Narrowing - Evidence from 1995 NPTS Author: Zhang, Jihong, Rufolo, Anthony M., Dueker, Kenneth, Strathman, James G. Year: 2000 Spreading of the peak is one effect of increased peak-period congestion. Due to peak spreading, the travel-time impact of congestion is mitigated for some travelers, but the inconvenience of traveling at a less-preferred time also has a cost. Alternatively, increases in capacity have their impacts on peak-period congestion mitigated by a narrowing of the peak. This reduces the travel-time savings, but it generates a benefit for those traveling closer to their preferred times. This benefit from capacity improvements has largely been ignored, and one reason is the difficulty of quantifying the effect. This paper reports on some crude attempts to quantify the peak-narrowing effect of increased capacity. Using 1995 Nationwide Personal Transportation Survey (NPTS) data, this study investigates how workers in Metropolitan Statistical Areas (MSAs) in the US respond to roadway capacity differences in terms of changing their departure time to work. It is assumed that there is some distribution of travel times given by a mean and some measure of deviation from the mean. Peak narrowing is then measured by decreases in the deviation from the mean. The peak narrowing effects are modeled for both the morning commute and all departures from home for work at any time of the day. As expected, in urban areas with higher roadway capacity per capita, workers tend to depart from home closer to the peak time. For the morning commute, the model estimates that each one-percent increase in lane-miles per capita results in workers departing from home about 5.75 percent closer to the peak time. The effects of roadway capacity are found to be statistically significant in both models. Close

• 3. [Article] Bicycle Level of Service: Where are the Gaps in Bicycle Flow Measures?

  Bicycle use is increasing in many parts of the U.S. Local and regional governments have set ambitious bicycle mode share goals as part of their strategy to curb greenhouse gas emissions and relieve traffic ...

  Citation × Citation Citation Abstract Copy Title: Bicycle Level of Service: Where are the Gaps in Bicycle Flow Measures? Author: Johnson, Pamela Christine Year: 2014 Bicycle use is increasing in many parts of the U.S. Local and regional governments have set ambitious bicycle mode share goals as part of their strategy to curb greenhouse gas emissions and relieve traffic congestion. In particular, Portland, Oregon has set a 25% mode share goal for 2030 (PBOT 2010). Currently bicycle mode share in Portland is 6.1% of all trips. Other cities and regional planning organizations are also setting ambitious bicycle mode share goals and increasing bicycle facilities and programs to encourage bicycling. Increases in bicycle mode share are being encouraged to increase. However, cities with higher-than-average bicycle mode share are beginning to experience locations with bicycle traffic congestion, especially during peak commute hours. Today, there are no established methods are used to describe or measure bicycle traffic flows. In the 1960s, the Highway Capacity Manual (HCM) introduced Level of Service (LOS) measurements to describe traffic flow and capacity of motor vehicles on highways using an A-to-F grading system; "A" describes free flow traffic with no maneuvering constraints for the driver and an "F" grade corresponds to over capacity situations in which traffic flow breaks down or becomes "jammed". LOS metrics were expanded to highway and road facilities, operations and design. In the 1990s, the HCM introduced LOS measurements for transit, pedestrians, and bicycles. Today, there are many well established and emerging bicycle level of service (BLOS) methods that measure the stress, comfort and perception of safety of bicycle facilities. However, it was been assumed that bicycle traffic volumes are low and do not warrant the use of a LOS measure for bicycle capacity and traffic flow. There are few BLOS methods that take bicycle flow into consideration, except for in the case of separated bicycle and bicycle-pedestrian paths. This thesis investigated the state of BLOS capacity methods that use bicycle volumes as a variable. The existing methods were applied to bicycle facility elements along a corridor that experiences high bicycle volumes in Portland, Oregon. Using data from the study corridor, BLOS was calculated and a sensitivity analysis was applied to each of the methods to determine how sensitive the models are to each of the variables used. An intercept survey was conducted to compare the BLOS capacity scores calculated for the corridor with the users' perception. In addition, 2030 bicycle mode share for the study corridor was estimated and the implications of increased future bicycle congestion were discussed. Gaps in the BLOS methods, limitations of the thesis study and future research were summarized. In general, the existing methods for BLOS capacity are intended for separated paths; they are not appropriate for existing high traffic flow facilities. Most of the BLOS traffic flow methods that have been developed are most sensitive to bicycle volumes. Some of these models may be a good starting point to improve BLOS capacity and traffic flow measures for high bicycle volume locations. Without the tools to measure and evaluate the patterns of bicycle capacity and traffic flow, it will be difficult to monitor and mitigate bicycle congestion and to plan for efficient bicycle facilities in the future. This report concludes that it is now time to develop new BLOS capacity measures that address bicycle traffic flow. Title: Bicycle Level of Service: Where are the Gaps in Bicycle Flow Measures? Author: Johnson, Pamela Christine Year: 2014 Bicycle use is increasing in many parts of the U.S. Local and regional governments have set ambitious bicycle mode share goals as part of their strategy to curb greenhouse gas emissions and relieve traffic congestion. In particular, Portland, Oregon has set a 25% mode share goal for 2030 (PBOT 2010). Currently bicycle mode share in Portland is 6.1% of all trips. Other cities and regional planning organizations are also setting ambitious bicycle mode share goals and increasing bicycle facilities and programs to encourage bicycling. Increases in bicycle mode share are being encouraged to increase. However, cities with higher-than-average bicycle mode share are beginning to experience locations with bicycle traffic congestion, especially during peak commute hours. Today, there are no established methods are used to describe or measure bicycle traffic flows. In the 1960s, the Highway Capacity Manual (HCM) introduced Level of Service (LOS) measurements to describe traffic flow and capacity of motor vehicles on highways using an A-to-F grading system; "A" describes free flow traffic with no maneuvering constraints for the driver and an "F" grade corresponds to over capacity situations in which traffic flow breaks down or becomes "jammed". LOS metrics were expanded to highway and road facilities, operations and design. In the 1990s, the HCM introduced LOS measurements for transit, pedestrians, and bicycles. Today, there are many well established and emerging bicycle level of service (BLOS) methods that measure the stress, comfort and perception of safety of bicycle facilities. However, it was been assumed that bicycle traffic volumes are low and do not warrant the use of a LOS measure for bicycle capacity and traffic flow. There are few BLOS methods that take bicycle flow into consideration, except for in the case of separated bicycle and bicycle-pedestrian paths. This thesis investigated the state of BLOS capacity methods that use bicycle volumes as a variable. The existing methods were applied to bicycle facility elements along a corridor that experiences high bicycle volumes in Portland, Oregon. Using data from the study corridor, BLOS was calculated and a sensitivity analysis was applied to each of the methods to determine how sensitive the models are to each of the variables used. An intercept survey was conducted to compare the BLOS capacity scores calculated for the corridor with the users' perception. In addition, 2030 bicycle mode share for the study corridor was estimated and the implications of increased future bicycle congestion were discussed. Gaps in the BLOS methods, limitations of the thesis study and future research were summarized. In general, the existing methods for BLOS capacity are intended for separated paths; they are not appropriate for existing high traffic flow facilities. Most of the BLOS traffic flow methods that have been developed are most sensitive to bicycle volumes. Some of these models may be a good starting point to improve BLOS capacity and traffic flow measures for high bicycle volume locations. Without the tools to measure and evaluate the patterns of bicycle capacity and traffic flow, it will be difficult to monitor and mitigate bicycle congestion and to plan for efficient bicycle facilities in the future. This report concludes that it is now time to develop new BLOS capacity measures that address bicycle traffic flow. Close

• 4. [Article] No More Freeways: Urban Land Use-Transportation Dynamics without Freeway Capacity Expansion

  Observations of the various limitations of freeway capacity expansion have led to a provocative planning and policy question – What if we completely stop building additional freeway capacity. From a theoretical ...

  Citation × Citation Citation Abstract Copy Title: No More Freeways: Urban Land Use-Transportation Dynamics without Freeway Capacity Expansion Author: Zhang, Lei, Xu, We Year: 2011 Observations of the various limitations of freeway capacity expansion have led to a provocative planning and policy question – What if we completely stop building additional freeway capacity. From a theoretical perspective, as a freeway transportation network matures, there exists a saturation point beyond which any additional freeway capacity would only be counterproductive from a welfare point of view, and worsen the existing urban transportation problems. Traditional benefit/cost analysis of individual freeway capacity expansion projects often ignores long-term induced demand and land use changes and does not represent a systems approach to this important theoretical issue. From a practical perspective, a no-more-freeway policy can relieve transportation funds for other potentially more effective usages, such as improving urban arterial street system, improving transit level of service and coverage, implementing demand management and pricing strategies, and facilitating more efficient land use patterns (e.g. high density in-fill and transit-oriented developments). This research answers the following critical land use-transportation planning questions. Improved knowledge on these issues should benefit planers and decision-makers who pursue mobility and sustainability objectives and have the power to shape future cities. (1). Under what conditions will freeway capacity expansion become counterproductive to urban planning objectives (where is the saturation point)? (2). How will land use and transportation evolve under a “No-More-Freeway” policy? (3). What are the implications of such a policy on congestion, land use efficiency, transportation finance, and social welfare? (4). What is the impact of a less restrictive “No-More-Freeway” policy that only allows private-section freeway investments and relieves public-section freeway investments for other compelling transportation needs. The analysis in this project builds upon a modeling tool, ABSOLUTE, developed by the P.I. in previous research projects. ABSOLUTE is an Agent-Based Simulator Of Land Use-Transportation Evolution, which translates planning policies such as the “No-More- Freeway” policy into alternative urban growth paths and possibly urban growth equilibria (land use and transportation system equilibria). Due to the “Small Start” nature of this OTREC project, the analysis focuses primarily on stylized urban areas, and empirical analysis of the “No-More- Freeway” policy is only conducted for one policy scenario on the Twin Cities, MN, area. Title: No More Freeways: Urban Land Use-Transportation Dynamics without Freeway Capacity Expansion Author: Zhang, Lei, Xu, We Year: 2011 Observations of the various limitations of freeway capacity expansion have led to a provocative planning and policy question – What if we completely stop building additional freeway capacity. From a theoretical perspective, as a freeway transportation network matures, there exists a saturation point beyond which any additional freeway capacity would only be counterproductive from a welfare point of view, and worsen the existing urban transportation problems. Traditional benefit/cost analysis of individual freeway capacity expansion projects often ignores long-term induced demand and land use changes and does not represent a systems approach to this important theoretical issue. From a practical perspective, a no-more-freeway policy can relieve transportation funds for other potentially more effective usages, such as improving urban arterial street system, improving transit level of service and coverage, implementing demand management and pricing strategies, and facilitating more efficient land use patterns (e.g. high density in-fill and transit-oriented developments). This research answers the following critical land use-transportation planning questions. Improved knowledge on these issues should benefit planers and decision-makers who pursue mobility and sustainability objectives and have the power to shape future cities. (1). Under what conditions will freeway capacity expansion become counterproductive to urban planning objectives (where is the saturation point)? (2). How will land use and transportation evolve under a “No-More-Freeway” policy? (3). What are the implications of such a policy on congestion, land use efficiency, transportation finance, and social welfare? (4). What is the impact of a less restrictive “No-More-Freeway” policy that only allows private-section freeway investments and relieves public-section freeway investments for other compelling transportation needs. The analysis in this project builds upon a modeling tool, ABSOLUTE, developed by the P.I. in previous research projects. ABSOLUTE is an Agent-Based Simulator Of Land Use-Transportation Evolution, which translates planning policies such as the “No-More- Freeway” policy into alternative urban growth paths and possibly urban growth equilibria (land use and transportation system equilibria). Due to the “Small Start” nature of this OTREC project, the analysis focuses primarily on stylized urban areas, and empirical analysis of the “No-More- Freeway” policy is only conducted for one policy scenario on the Twin Cities, MN, area. Close

• 5. [Article] Land Use and Growth Impacts from Highway Capacity Increases

  This analysis examined the historical relationship between land use changes and the location of capacity increasing highway projects in the State of Oregon from 1970 to 1990. Aerial photography for 18 ...

  Citation × Citation Citation Abstract Copy Title: Land Use and Growth Impacts from Highway Capacity Increases Author: Sanchez, Erik J Year: 2000 This analysis examined the historical relationship between land use changes and the location of capacity increasing highway projects in the State of Oregon from 1970 to 1990. Aerial photography for 18 cities was used to delineate the extent of urban development in each time period. A geographic information system (GIS) was used to assemble the data. Using this data, a logit regression model tested the significance of geographic variables such as proximity to highway projects, land use zoning classification, city size, and other spatial characteristics. The analytical methods used in this study incorporated a set of commonly used techniques to assess highway impacts on urban development patterns. The results suggest that for the 18 selected cities, the spatial measures performed well in predicting the location of urban development from 1970 to 1990. In addition, the results of the logit regression model indicated that controlling for other location factors, urban development had not clustered along state high project corridors as was suspected. Title: Land Use and Growth Impacts from Highway Capacity Increases Author: Sanchez, Erik J Year: 2000 This analysis examined the historical relationship between land use changes and the location of capacity increasing highway projects in the State of Oregon from 1970 to 1990. Aerial photography for 18 cities was used to delineate the extent of urban development in each time period. A geographic information system (GIS) was used to assemble the data. Using this data, a logit regression model tested the significance of geographic variables such as proximity to highway projects, land use zoning classification, city size, and other spatial characteristics. The analytical methods used in this study incorporated a set of commonly used techniques to assess highway impacts on urban development patterns. The results suggest that for the 18 selected cities, the spatial measures performed well in predicting the location of urban development from 1970 to 1990. In addition, the results of the logit regression model indicated that controlling for other location factors, urban development had not clustered along state high project corridors as was suspected. Close

• 6. [Article] Environmental Durability of Reinforced Concrete Deck Girders Strengthened for Shear with Surface Bonded Carbon Fiber-Reinforced Polymer

  This research investigated the durability of carbon fiber-reinforced polymer composites (CFRP) used for shear strengthening reinforced concrete deck girders. Large beams were used to avoid accounting for ...

  Citation × Citation Citation Abstract Copy Title: Environmental Durability of Reinforced Concrete Deck Girders Strengthened for Shear with Surface Bonded Carbon Fiber-Reinforced Polymer Author: Higgins, Christopher, Dawson, Matthew R., Mitchell, Mikal M., Sopal, Gautam, Senturk, A. Ekin Year: 2009 This research investigated the durability of carbon fiber-reinforced polymer composites (CFRP) used for shear strengthening reinforced concrete deck girders. Large beams were used to avoid accounting for size effects in the data analysis. The effort included determining the role of freeze-thaw, moisture, and fatigue on structural performance and developing analytical design procedures that account for durability. The results showed that moisture infiltration behind the CFRP, combined with freeze-thaw, was critical in reducing shear panel stiffness and shear capacity. Long-term moisture exposure alone produced only a minor decrease in shear capacity. Freeze-thaw, combined with fatigue, had little effect on shear capacity if water infiltration was minimized. Fatigue caused some debonding, but the debonding was not significant enough to affect capacity. Use of ACI-318 with ACI 440 provided conservative predicted shear strengths after environmental exposure. However, the ACI approach did not provide uniform levels of safety because the observed conservatism was built into the prediction for the unstrengthened base specimens but not for the CFRP contribution. Consequently, a recommendation of the research is to apply the environmental exposure factor at the final design step to limit the effective CFRP stress/strain. For locations with very large numbers of wet freeze-thaw cycles and extended exposure to continuous moisture, the environmental reduction factors should be reduced even further. To better predict the CFRP bond strength demands that can occur due to shear-moment interaction, a further check of the design should be made beyond those required by ACI-440. Title: Environmental Durability of Reinforced Concrete Deck Girders Strengthened for Shear with Surface Bonded Carbon Fiber-Reinforced Polymer Author: Higgins, Christopher, Dawson, Matthew R., Mitchell, Mikal M., Sopal, Gautam, Senturk, A. Ekin Year: 2009 This research investigated the durability of carbon fiber-reinforced polymer composites (CFRP) used for shear strengthening reinforced concrete deck girders. Large beams were used to avoid accounting for size effects in the data analysis. The effort included determining the role of freeze-thaw, moisture, and fatigue on structural performance and developing analytical design procedures that account for durability. The results showed that moisture infiltration behind the CFRP, combined with freeze-thaw, was critical in reducing shear panel stiffness and shear capacity. Long-term moisture exposure alone produced only a minor decrease in shear capacity. Freeze-thaw, combined with fatigue, had little effect on shear capacity if water infiltration was minimized. Fatigue caused some debonding, but the debonding was not significant enough to affect capacity. Use of ACI-318 with ACI 440 provided conservative predicted shear strengths after environmental exposure. However, the ACI approach did not provide uniform levels of safety because the observed conservatism was built into the prediction for the unstrengthened base specimens but not for the CFRP contribution. Consequently, a recommendation of the research is to apply the environmental exposure factor at the final design step to limit the effective CFRP stress/strain. For locations with very large numbers of wet freeze-thaw cycles and extended exposure to continuous moisture, the environmental reduction factors should be reduced even further. To better predict the CFRP bond strength demands that can occur due to shear-moment interaction, a further check of the design should be made beyond those required by ACI-440. Close

• 7. [Article] Providing Capacity in Rural Communities: Planning for Alternative Transportation

  This technology transfer proposal linked service learning with rural multimodal transportation planning through a collaborative partnership between University of Oregon (UO) experiential learning programs ...

  Citation × Citation Citation Abstract Copy Title: Providing Capacity in Rural Communities: Planning for Alternative Transportation Author: Smith, Megan Year: 2011 This technology transfer proposal linked service learning with rural multimodal transportation planning through a collaborative partnership between University of Oregon (UO) experiential learning programs and three rural Oregon communities. As this planning and technical support to rural communities occurred, lessons learned were gathered and will support future servicelearning projects focused on transportation planning. The primary products for this project are the: (1) Completion of multimodal transportation planning projects that increase rural community capacity; and (2) a website with resources for communities, faculty and students. Three further outcomes were: (1) Increased capacity for transportation planning in rural communities; (2) Increased capacity in existing transportation planning professionals working in rural communities; and (3) Increased capacity in young planning professional and graduate students. This project was be led by the Community Service Center (CSC) at the UO and engaged two programs of the CSC. Resource Assistance for Rural Environments (RARE), founded in 1994, is a field based service learning program, affiliated with the UO’s Department of Planning, Public Policy and Management (PPPM). Each year RARE places 20 graduate level participants in rural Oregon communities where they live for 11 months while working for local agencies on planning and community development projects. Community Planning Workshop (CPW) is an experiential learning program also affiliated with PPPM. Established in 1977, CPW is campus-based, with teams of graduate students working on projects for public and non-profit organizations. Product One: Three community projects focused on multi-modal transportation planning were selected as RARE host sites. These projects included: a bike/pedestrian trails planning project with the City of Lebanon and Build Lebanon Trails, a local non-profit; a bike/pedestrian trails planning project with the City of Warrenton and Warrenton Trails Committee; and transportation needs assessment for the Rogue Valley Transportation District. These projects were selected from a pool of applicants based on project feasibility, community support, and host agency support of the CSC’s service learning objectives. In October 2007, three RARE participants were placed in these three communities and worked closely with local community supervisors to complete planning projects that specifically address multimodal transportation planning. The deliverables were multi-modal planning and projects, specifically addressing public, bike/pedestrian and recreation-related transportation, in three rural communities. Product Two: Through the creation of a website with lessons learned and example projects, the knowledge gained in developing the plans and projects is being disseminated. Title: Providing Capacity in Rural Communities: Planning for Alternative Transportation Author: Smith, Megan Year: 2011 This technology transfer proposal linked service learning with rural multimodal transportation planning through a collaborative partnership between University of Oregon (UO) experiential learning programs and three rural Oregon communities. As this planning and technical support to rural communities occurred, lessons learned were gathered and will support future servicelearning projects focused on transportation planning. The primary products for this project are the: (1) Completion of multimodal transportation planning projects that increase rural community capacity; and (2) a website with resources for communities, faculty and students. Three further outcomes were: (1) Increased capacity for transportation planning in rural communities; (2) Increased capacity in existing transportation planning professionals working in rural communities; and (3) Increased capacity in young planning professional and graduate students. This project was be led by the Community Service Center (CSC) at the UO and engaged two programs of the CSC. Resource Assistance for Rural Environments (RARE), founded in 1994, is a field based service learning program, affiliated with the UO’s Department of Planning, Public Policy and Management (PPPM). Each year RARE places 20 graduate level participants in rural Oregon communities where they live for 11 months while working for local agencies on planning and community development projects. Community Planning Workshop (CPW) is an experiential learning program also affiliated with PPPM. Established in 1977, CPW is campus-based, with teams of graduate students working on projects for public and non-profit organizations. Product One: Three community projects focused on multi-modal transportation planning were selected as RARE host sites. These projects included: a bike/pedestrian trails planning project with the City of Lebanon and Build Lebanon Trails, a local non-profit; a bike/pedestrian trails planning project with the City of Warrenton and Warrenton Trails Committee; and transportation needs assessment for the Rogue Valley Transportation District. These projects were selected from a pool of applicants based on project feasibility, community support, and host agency support of the CSC’s service learning objectives. In October 2007, three RARE participants were placed in these three communities and worked closely with local community supervisors to complete planning projects that specifically address multimodal transportation planning. The deliverables were multi-modal planning and projects, specifically addressing public, bike/pedestrian and recreation-related transportation, in three rural communities. Product Two: Through the creation of a website with lessons learned and example projects, the knowledge gained in developing the plans and projects is being disseminated. Close

• 8. [Article] Value of Travel Time Reliability Part II: A Study of Tradeoffs Between Travel Reliability, Congestion Mitigation Strategies and Emissions

  Capacity, demand, and vehicle based emissions reduction strategies are compared for several pollutants employing aggregate US congestion and vehicle fleet condition data. We find that congestion mitigation ...

  Citation × Citation Citation Abstract Copy Title: Value of Travel Time Reliability Part II: A Study of Tradeoffs Between Travel Reliability, Congestion Mitigation Strategies and Emissions Author: Figliozzi, Miguel A., Bigazzi, Alexander Y. Year: 2012 Capacity, demand, and vehicle based emissions reduction strategies are compared for several pollutants employing aggregate US congestion and vehicle fleet condition data. We find that congestion mitigation does not inevitably lead to reduced emissions; the net effect of mitigation depends on the balance of induced travel demand and increased vehicle efficiency that in turn depend on the pollutant, congestion level, and fleet composition. In the long run, capacity-based congestion improvements within certain speed intervals can reasonably be expected to increase emissions of CO2e, CO, and NOx through increased vehicle travel volume. Better opportunities for emissions reductions exist for HC and PM2.5 emissions, and on more heavily congested arterials. Advanced-efficiency vehicles with emissions rates that are less sensitive to congestion than conventional vehicles generate less emissions co-benefits from congestion mitigation. Title: Value of Travel Time Reliability Part II: A Study of Tradeoffs Between Travel Reliability, Congestion Mitigation Strategies and Emissions Author: Figliozzi, Miguel A., Bigazzi, Alexander Y. Year: 2012 Capacity, demand, and vehicle based emissions reduction strategies are compared for several pollutants employing aggregate US congestion and vehicle fleet condition data. We find that congestion mitigation does not inevitably lead to reduced emissions; the net effect of mitigation depends on the balance of induced travel demand and increased vehicle efficiency that in turn depend on the pollutant, congestion level, and fleet composition. In the long run, capacity-based congestion improvements within certain speed intervals can reasonably be expected to increase emissions of CO2e, CO, and NOx through increased vehicle travel volume. Better opportunities for emissions reductions exist for HC and PM2.5 emissions, and on more heavily congested arterials. Advanced-efficiency vehicles with emissions rates that are less sensitive to congestion than conventional vehicles generate less emissions co-benefits from congestion mitigation. Close

• 9. [Article] A GIS Methodology for Assessing the Growth Impacts of Highway Improvements

  This paper presents a methodology to assess the induced land use effects of state highway improvements on urban development patterns. The methodology is applied to the case study City of Hillsboro, Oregon ...

  Citation × Citation Citation Abstract Copy Title: A GIS Methodology for Assessing the Growth Impacts of Highway Improvements Author: Sanchez, Thomas W., Dueker, Kenneth Year: 1998 This paper presents a methodology to assess the induced land use effects of state highway improvements on urban development patterns. The methodology is applied to the case study City of Hillsboro, Oregon and illustrates a framework for data management and analysis. A set of temporal land use characteristics and spatial measures are used as predictors of urban development activities resulting from highway accessibility improvements. A multiple regression analysis tests the significance of these variables in predicting rates and locations of urban development. The primary objective of this research is to identify the relationship between capacity increasing highway improvements and changes in urban development. The analysis provides quantifiable indicators that describe the urban development trends associated with the City of Hillsboro. Title: A GIS Methodology for Assessing the Growth Impacts of Highway Improvements Author: Sanchez, Thomas W., Dueker, Kenneth Year: 1998 This paper presents a methodology to assess the induced land use effects of state highway improvements on urban development patterns. The methodology is applied to the case study City of Hillsboro, Oregon and illustrates a framework for data management and analysis. A set of temporal land use characteristics and spatial measures are used as predictors of urban development activities resulting from highway accessibility improvements. A multiple regression analysis tests the significance of these variables in predicting rates and locations of urban development. The primary objective of this research is to identify the relationship between capacity increasing highway improvements and changes in urban development. The analysis provides quantifiable indicators that describe the urban development trends associated with the City of Hillsboro. Close

• 10. [Article] Application of LRFD Geotechnical Principles for Pile Supported Bridges in Oregon: Phase 1

  Bridge foundations must be designed based on acceptable risks of failure. To secure rapid implementation of Load Resistance Factor Design (LRFD) principles for foundation design, the American Association ...

  Citation × Citation Citation Abstract Copy Title: Application of LRFD Geotechnical Principles for Pile Supported Bridges in Oregon: Phase 1 Author: Smith, Trevor D., Dusicka, Peter Year: 2009 Bridge foundations must be designed based on acceptable risks of failure. To secure rapid implementation of Load Resistance Factor Design (LRFD) principles for foundation design, the American Association of State Highway and Transportation Officials (AASHTO) and the Federal Highway Administration (FHWA) are requiring their use through AASHTO code. The Bridge Section of the Oregon Department of Transportation (ODOT) has responsibility for satisfactory design of all the bridge structures across the state’s highway system. The widespread geotechnical adoption of the LRFD code throughout state DOTs has been difficult in the case of deep foundations due to regional differences and in some cases a lack of any close match to DOT foundation practices. This lack of matching stems from the source research conducted on which the code is based, documented as NCHRP 507. For ODOT, the evaluation of nominal axial static capacity for each driven pile in the field is conducted by dynamic methods and AASHTO offers resistance factors for these techniques. ODOT typically uses the wave equation software (WEAP) applied at the end of initial driving, EOID, and occasionally at the beginning of pile restrike (BOR) to capture increases in capacity from set-up. This study reports that, based on past and new surveys, ODOT practice is reasonably typical for DOT practice in sands, silts, and clays. The AASHTO resistance factor, φ, for WEAP is at EOID and is too low for the efficient design of piles to match the likely probabilities of pile failure. The survey of Northwest state DOTs revealed that 80% of the DOTs believe that a φ of 0.4 is conservative and 37.5 % do not use the AASHTO-sanctioned φ of 0.4. Matching LRFD to allowable stress design (ASD) by direct calibration for a single pile, without any reported capacity bias, sets φ as 0.55 to match the ASD factor of safety of 2.5. An ODOT case history of a recently completed pilesupported bridge designed and constructed to FHWA and AASHTO ASD standards in use at that time, shows the number of piles at the bent studied would be doubled under new AASHTO requirements. This suggests the standard will add considerable pile foundation costs to all new bridges. This cost increase is a strong incentive to complete statistical recalibration of GRLWEAP dynamic capacity resistance value in a Phase 2 of this study. Title: Application of LRFD Geotechnical Principles for Pile Supported Bridges in Oregon: Phase 1 Author: Smith, Trevor D., Dusicka, Peter Year: 2009 Bridge foundations must be designed based on acceptable risks of failure. To secure rapid implementation of Load Resistance Factor Design (LRFD) principles for foundation design, the American Association of State Highway and Transportation Officials (AASHTO) and the Federal Highway Administration (FHWA) are requiring their use through AASHTO code. The Bridge Section of the Oregon Department of Transportation (ODOT) has responsibility for satisfactory design of all the bridge structures across the state’s highway system. The widespread geotechnical adoption of the LRFD code throughout state DOTs has been difficult in the case of deep foundations due to regional differences and in some cases a lack of any close match to DOT foundation practices. This lack of matching stems from the source research conducted on which the code is based, documented as NCHRP 507. For ODOT, the evaluation of nominal axial static capacity for each driven pile in the field is conducted by dynamic methods and AASHTO offers resistance factors for these techniques. ODOT typically uses the wave equation software (WEAP) applied at the end of initial driving, EOID, and occasionally at the beginning of pile restrike (BOR) to capture increases in capacity from set-up. This study reports that, based on past and new surveys, ODOT practice is reasonably typical for DOT practice in sands, silts, and clays. The AASHTO resistance factor, φ, for WEAP is at EOID and is too low for the efficient design of piles to match the likely probabilities of pile failure. The survey of Northwest state DOTs revealed that 80% of the DOTs believe that a φ of 0.4 is conservative and 37.5 % do not use the AASHTO-sanctioned φ of 0.4. Matching LRFD to allowable stress design (ASD) by direct calibration for a single pile, without any reported capacity bias, sets φ as 0.55 to match the ASD factor of safety of 2.5. An ODOT case history of a recently completed pilesupported bridge designed and constructed to FHWA and AASHTO ASD standards in use at that time, shows the number of piles at the bent studied would be doubled under new AASHTO requirements. This suggests the standard will add considerable pile foundation costs to all new bridges. This cost increase is a strong incentive to complete statistical recalibration of GRLWEAP dynamic capacity resistance value in a Phase 2 of this study. Close