1. Best Practices Related to Research Problem Identification, Scoping, and Programming: A Researcher’s View Martin Pietrucha, Director The Thomas D. Larson Pennsylvania Transportation Institute THE LARSON INSTITUTE

2. Background State DOTs employ many methods for soliciting research ideas Informal calls/emails from technicians, engineers, and administrators to the research staff Formal application procedures that require: – Background materials – Scoping statement – Specific research tasks THE LARSON INSTITUTE

3. Issues Identification of research problems by staff who are not regularly involved in research leads to requests for proposals that are too proscriptive; which, in turn, tie the researchers hands in proposing an optimal research work plan. Most researchers would find it preferable if department staff would identify problems they encounter in their day- to-day work rather than trying to scope out “research problem statements.” Given that most departments have more research problems than their research budgets will allow them to fully investigate, there seems to be no single optimal process to evaluate individual project requests for prioritization within the research program. THE LARSON INSTITUTE

4. Proscriptive/Restrictive Background for NCHRP Project 03-96, Analysis of Managed Lanes on Freeway Facilities Managed lanes are becoming more prevalent on freeway facilities and their operational and geometric characteristics vary greatly. While there is no nationally recognized definition of managed lanes, for the purposes of this project, managed lanes are considered to include high-occupancy vehicle (HOV) lanes, high- occupancy/toll (HOT) lanes, and express toll lanes. The Highway Capacity Manual (HCM) includes methodologies for analyzing freeway facilities but it does not address managed lanes. Some of the reasons that HCM freeway methodologies may not apply to managed lanes are: (1) unique access patterns with general purpose lanes, (2) significant speed differentials between adjacent lanes, and (3) no opportunities for passing on single managed lanes. A better understanding of the operational characteristics of freeway facilities with managed lanes is needed. Transportation agencies need information on the performance of the managed and general purpose lanes to plan the facility and determine the pricing strategy to manage demand. Including performance assessment and operational analysis of managed lanes in the HCM would greatly enhance its usefulness to engineers, designers, planners, and decision makers. THE LARSON INSTITUTE

5. Proscriptive/Restrictive Background for NCHRP Project 03-96, Analysis of Managed Lanes on Freeway Facilities Managed lanes are becoming more prevalent on freeway facilities and their operational and geometric characteristics vary greatly. While there is no nationally recognized definition of managed lanes, for the purposes of this project, managed lanes are considered to include high-occupancy vehicle (HOV) lanes, high- occupancy/toll (HOT) lanes, and express toll lanes. The Highway Capacity Manual (HCM) includes methodologies for analyzing freeway facilities but it does not address managed lanes. Some of the reasons that HCM freeway methodologies may not apply to managed lanes are: (1) unique access patterns with general purpose lanes, (2) significant speed differentials between adjacent lanes, and (3) no opportunities for passing on single managed lanes. A better understanding of the operational characteristics of freeway facilities with managed lanes is needed. Transportation agencies need information on the performance of the managed and general purpose lanes to plan the facility and determine the pricing strategy to manage demand. Including performance assessment and operational analysis of managed lanes in the HCM would greatly enhance its usefulness to engineers, designers, planners, and decision makers. THE LARSON INSTITUTE

6. Proscriptive/Restrictive TASKS Task 1. Conduct a literature review on the design and operation of managed lanes and summarize information on performance measures and operational analysis methods for managed lanes. Review the latest methods for determining speed-flow-density curves and capacities on freeway segments. Catalog the different types of managed lane designs (e.g., barrier-separated, buffer-separated, non-separated, access point design, typical sections, single lane and multi-lane, reversible). Task 2. Develop a performance-measurement framework for freeway facilities comprising both managed and general purpose lanes. The framework should include performance measures for the managed and general purpose lanes and consider the use of composite measures for the facility. The performance-measurement framework should provide inputs to toll demand models commonly used for managed lanes and allow transportation agencies to assess the facility’s operation and convey system performance information to the public. Task 3. Develop a data collection and analysis plan to support Tasks 6 and 7. Data from existing traffic management systems and transit vehicle locator systems on facilities with managed lanes should be used as practical, augmented by original data collection as project resources allow. Data collection sites should include facilities with single and multiple managed lanes and cover the full range of designs for separation between the general purpose and managed lanes. If adequate field data are not available or feasible to collect, validated microscopic simulation models may be used to generate synthetic data if the models are properly calibrated and the results thoroughly documented. Task 4. Within 4 months of the contract start date, submit an interim report summarizing Tasks 1 through 3. The interim report shall also contain a detailed, updated work plan and an updated budget for the remaining tasks. Task 5. Carry out the Task 3 data collection plan as approved at the interim meeting. Task 6. Assess the applicability of the HCM 2010 freeway analysis methodologies to single- and multi-lane managed-lane operations, including the effects of cross-sectional elements. Determine whether these methodologies can be modified to properly model the operation of managed lanes. Discuss the results in a web conference with the panel. Task 7. Develop methodologies for quantifying the performance measures identified in Task 2 for managed lanes, including their access points and termini. The methodologies should account for the effect of transit and other heavy vehicles on the managed lanes. The methodologies should also account for the effect slower-moving traffic in an adjacent general purpose lane has on uncongested managed- lane traffic for different types of separation. The methodologies should include speed-flow-density curves based on field data and recommend maximum service flows, recognizing that managed lanes are intended to operate uncongested. Describe limitations of the methodologies and situations where alternative analysis tools should be used. Task 8. Develop a computational engine for the Task 7 methodologies, based on HCM 2010 requirements and building upon HCM 2010 modules as applicable. The computational engine should follow the documentation requirements for the HCM 2010. Task 9. Prepare draft text for the HCM, either as part of the Freeway Facilities chapter or as a separate chapter. Task 10. Submit a final report that documents the entire research effort and includes the Task 9 text as an appendix. THE LARSON INSTITUTE

7. Proscriptive/Restrictive TASKS Task 1. Conduct a literature review on the design and operation of managed lanes and summarize information on performance measures and operational analysis methods for managed lanes. Review the latest methods for determining speed-flow-density curves and capacities on freeway segments. Catalog the different types of managed lane designs (e.g., barrier-separated, buffer-separated, non-separated, access point design, typical sections, single lane and multi-lane, reversible). Task 2. Develop a performance-measurement framework for freeway facilities comprising both managed and general purpose lanes. The framework should include performance measures for the managed and general purpose lanes and consider the use of composite measures for the facility. The performance-measurement framework should provide inputs to toll demand models commonly used for managed lanes and allow transportation agencies to assess the facility’s operation and convey system performance information to the public. Task 3. Develop a data collection and analysis plan to support Tasks 6 and 7. Data from existing traffic management systems and transit vehicle locator systems on facilities with managed lanes should be used as practical, augmented by original data collection as project resources allow. Data collection sites should include facilities with single and multiple managed lanes and cover the full range of designs for separation between the general purpose and managed lanes. If adequate field data are not available or feasible to collect, validated microscopic simulation models may be used to generate synthetic data if the models are properly calibrated and the results thoroughly documented. THE LARSON INSTITUTE

8. Proscriptive/Restrictive TASKS Task 1. Conduct a literature review on the design and operation of managed lanes and summarize information on performance measures and operational analysis methods for managed lanes. Review the latest methods for determining speed-flow-density curves and capacities on freeway segments. Catalog the different types of managed lane designs (e.g., barrier-separated, buffer-separated, non-separated, access point design, typical sections, single lane and multi-lane, reversible). Task 2. Develop a performance-measurement framework for freeway facilities comprising both managed and general purpose lanes. The framework should include performance measures for the managed and general purpose lanes and consider the use of composite measures for the facility. The performance-measurement framework should provide inputs to toll demand models commonly used for managed lanes and allow transportation agencies to assess the facility’s operation and convey system performance information to the public. Task 3. Develop a data collection and analysis plan to support Tasks 6 and 7. Data from existing traffic management systems and transit vehicle locator systems on facilities with managed lanes should be used as practical, augmented by original data collection as project resources allow. Data collection sites should include facilities with single and multiple managed lanes and cover the full range of designs for separation between the general purpose and managed lanes. If adequate field data are not available or feasible to collect, validated microscopic simulation models may be used to generate synthetic data if the models are properly calibrated and the results thoroughly documented. THE LARSON INSTITUTE

9. Proscriptive/Restrictive TASKS Task 6. Assess the applicability of the HCM 2010 freeway analysis methodologies to single- and multi-lane managed-lane operations, including the effects of cross-sectional elements. Determine whether these methodologies can be modified to properly model the operation of managed lanes. Discuss the results in a web conference with the panel. Task 7. Develop methodologies for quantifying the performance measures identified in Task 2 for managed lanes, including their access points and termini. The methodologies should account for the effect of transit and other heavy vehicles on the managed lanes. The methodologies should also account for the effect slower-moving traffic in an adjacent general purpose lane has on uncongested managed-lane traffic for different types of separation. The methodologies should include speed-flow-density curves based on field data and recommend maximum service flows, recognizing that managed lanes are intended to operate uncongested. Describe limitations of the methodologies and situations where alternative analysis tools should be used. Task 8. Develop a computational engine for the Task 7 methodologies, based on HCM 2010 requirements and building upon HCM 2010 modules as applicable. The computational engine should follow the documentation requirements for the HCM 2010. THE LARSON INSTITUTE

10. Proscriptive/Restrictive TASKS Task 6. Assess the applicability of the HCM 2010 freeway analysis methodologies to single- and multi-lane managed-lane operations, including the effects of cross-sectional elements. Determine whether these methodologies can be modified to properly model the operation of managed lanes. Discuss the results in a web conference with the panel. Task 7. Develop methodologies for quantifying the performance measures identified in Task 2 for managed lanes, including their access points and termini. The methodologies should account for the effect of transit and other heavy vehicles on the managed lanes. The methodologies should also account for the effect slower-moving traffic in an adjacent general purpose lane has on uncongested managed-lane traffic for different types of separation. The methodologies should include speed-flow-density curves based on field data and recommend maximum service flows, recognizing that managed lanes are intended to operate uncongested. Describe limitations of the methodologies and situations where alternative analysis tools should be used. Task 8. Develop a computational engine for the Task 7 methodologies, based on HCM 2010 requirements and building upon HCM 2010 modules as applicable. The computational engine should follow the documentation requirements for the HCM 2010. THE LARSON INSTITUTE

11. Open-ended/Unconstrained Background NCHRP Project 15-42, Recommended Bicycle Lane Widths for Various Roadway Characteristics U.S. practitioners have minimal nationally recognized guidance regarding bicycle lane widths for various roadway and traffic characteristics. The current edition of the AASHTO Guide for the Development of Bicycle Facilities describes conditions under which bicycle lanes may be provided, but presents minimal design guidance on appropriate bicycle lane widths. For example, the Guide simply observes that “additional widths (more than 5 ft.) are desirable” where speeds exceed 50 mph or truck volume is heavy. Some transportation agencies use the minimum bicycle lane widths in the AASHTO Guide, while others have developed their own standards or refer to a 1994 FHWA study “Selecting Roadway Design Treatments to Accommodate Bicycles”. This report provides criteria tables for bicycle accommodations, including the use of bicycle lanes of either 5 ft or 6 ft in width. However, the authors described their recommendations as “preliminary” and the findings were not based on detailed research or analysis. It was anticipated that the tables would be refined as the state of the practice evolved, but no revision has been developed. THE LARSON INSTITUTE

12. Open-ended/Unconstrained OBJECTIVES The objectives of this project are to: – (1) develop recommended bicycle lane widths for various roadway and traffic characteristics, and – (2) identify conditions under which shared lanes are a viable alternative to marked bicycle lanes. PRODUCTS Recommended desired and minimum bicycle lane widths based on sound research findings that consider all relevant roadway and traffic (motor vehicle and bicycle) characteristics. A final report accompanied by proposed text for inclusion in relevant AASHTO design publications A PowerPoint presentation describing the background, objectives, research method, and findings of the study. Note: The products of the research should be applicable and appropriate for use in all regions of the United States. THE LARSON INSTITUTE