Chapter 6 Mobility Standards Appendix 6E Guidelines for Traffic Impact Studies and Air Quality Analysis Page 2 of 6

INTRODUCTION

The Louisville and Jefferson County Planning Commission requires that all traffic data and/or analysis either by a project proponent or opponent must be first reviewed by the Jefferson County Public Works and Transportation Division. This is to insure compliance with these guidelines and the comprehensive plan.

The purpose of this document is to provide guidance to developers and consultants regarding traffic impact studies and air quality analysis submitted as attachments to proposed development plans in Jefferson County, Kentucky. These studies can be useful decision making tools and. when warranted, are an important component of a development petition. These guidelines are intended to provide consistency in the preparation of impact studies. They are provided as a reference only. The analysis required for a traffic impact study should be conducted only under the supervision of a transportation engineer with specific training in traffic engineering. The air quality analysis should be conducted only by a professional certified by the Air Pollution Control District.

Notes which provide definitions for the technical terms discussed herein and those that should be addressed in an impact study are included in Appendix A. Elements of a recommended impact study are presented in Appendix B and sample traffic analysis forms are shown in Appendix D. The emission data required for air quality analysis generated by the Air Pollution Control District is presented in Appendix E. The major acceptable sources of information and reference are presented in Appendix F.
WARRANTS FOR REQUIRING AN IMPACT STUDY

The Jefferson County Public Works and Transportation Division (PW&T), as the initial step in the review process of a proposed development plan, will evaluate the need for a traffic impact study. The need for a traffic impact study will be determined on a case-by-case basis. The criteria described below will be used by the PW&T staff in its recommendations of need for a traffic impact study. The final decision to require a traffic impact study will be determined by the Director of Public Works, based on staff recommendations. If a traffic impact study is determined to be necessary, a report of the study's findings must be transmitted to and reviewed by PW&T staff before a recommendation on the proposed development plan will be made to the Planning Commission. For air quality concerns the APCD shall determine when an analysis performed by or for the developer is required. In most instances a traffic and air quality impact study would be jointly performed, however, either or both may be waived when conditions warrant.

The normal maximum time required for review and comment is two weeks. Should action be required of the APCD's Board this time would be extended to be compatible with the Boards regular monthly meeting every third Wednesday. An impact study may be requested if any of the following conditions are present:
1. Significantly Sized Project: The proposed development is of sufficient size to have a substantial impact on a particular local area. The proposed development is considered to meet this criteria if it generates two hundred (200) or more peak hour trips according to the current editions of Trip Generation, published by the Institute of Transportation Engineers, locally generated data or other acceptable source.
2. Nearby Congestion: The proposed development, of any size, is located near roadways, intersections or set of intersections which have been identified by the Director of Public Works as being already heavily congested.
3. Modification to Roadway: When the proposed development is located near a roadway segment identified by the Director of Public Works as within a problem area, needing to be widened or improved. This criteria will also be satisfied if the proposed development plan includes modifications to the State or County roadway system.
4. Traffic Control Signal: This warrant will be satisfied if the proposed development plan includes the installation of a new or the modification of an existing traffic control signal.
5. Air Quality: The proposed development is located in or will affect potential "Hot Spot" area, as identified in the Core Graphics of the Comprehensive Plan or an area of special air quality concern.
RECOMMENDED CONTENTS OF AN IMPACT STUDY

The developer shall be responsible for all data collection, analysis, and reporting associated with the traffic and air quality studies. The results of the developer's efforts will be reviewed by PW&T and APCD for content, results and acceptability. A single report documenting the traffic and air quality studies should be prepared. Traffic should be presented first since air quality analysis is dependent on traffic data.
1. Traffic Impact
  
  Generally a traffic impact study will provide operating capacity and level of service analysis for critical roadway segments and/or intersections within a predetermined impact area. Upon determination that a traffic impact study is required, the PW&T staff, with the petitioner, will identify the area of impact, the critical intersections to be analyzed and the scope of the study. Capacity and level of service analysis will be conducted for the following conditions:
  1. Existing traffic, to establish the current conditions as a point of reference;
  2. Existing plus expected natural traffic growth, and approved development projects not yet completed, if any, to establish the short term future traffic conditions without the proposed development;
  3. Full development traffic condition (including existing traffic, expected natural growth, approved development projects, and expected site generated traffic), to estimate future traffic conditions once the project is completed.
  [NOTE: If the proposed development is expected to be constructed in phases, over a period of years, analysis for each phase of development must be provided for each of the above conditions and should include a predetermined rate for natural growth of through traffic.]
  
  If the proposed development includes a request for rezoning, the study should also include an analysis comparing the traffic generated by the proposed development with the traffic generated by the existing zoning or land use/zoning recommendations in Corridor Plans or Neighborhood Plans. This analysis should be very brief, possibly consisting only of a table comparing the expected number of new trips generated by the recommended zoning and the proposed development plan. In addition, a short narrative should be present comparing the percentage or basic differences between the two scenarios.
  
  The individual parameters of the traffic impact study will be agreed upon during an initial review meeting between the petitioner and PW&T staff. These parameters may include, but not be limited to, the following:
  1. Boundary of the traffic impact area;
  2. Roadway segments and critical intersections to be included in the traffic impact study;
  3. Adequacy of available turning movement counts and need for additional data;
  4. Period of analysis (A.M. and/or P.M. peak hour weekday and/or weekend, depending on the development);
  5. Trip generation rates or acceptable sources to be used;
  6. Reductions to driveway trips due to internal circulation (if applicable);
  7. Percentage of trip reassignment to account for pass-by and diverted traffic.
  8. Directional distribution of site-generated traffic;
  9. Mode split assumptions (if applicable);
  10. Programmed projects in KIPDA's Transportation Improvement Program, the Comprehensive Plan's Core Graphics, along with travel demand estimating procedures for any assumptions relating to traffic diversion to new programmed facilities;
  11. Roadway capacity and trends in traffic growth;
  12. Acceptable methodologies to be used;
  13. The range of feasible traffic engineering and operational improvements associated with the development;
  14. Feasibility of including measures in the development proposal to promote transit ridership. This would require coordination with TARC and may include such provisions as transit stops and shelters with adequate pedestrian access, park-n-ride lots.
  15. Possibility of implementing other transportation system management strategies such as flex-time and variable work hour programs to redistribute peak hour traffic, employer ridesharing programs, preferential parking for ridesharers, etc.;
  16. Possibility of implementing provisions for alternative modes of transportation, such as bikeways, pedestrian walkways, including the provision of sidewalks along State Highways and along the County through roads system.
  17. The identification of high accident locations; and
  18. A formal cost estimate of mitigation measures, (including construction, design, right-of-way and utility relocation cost). Approval of the above parameters must be given by the PW&T at this initial meeting. It is recommended that the developer, or his representative, document the discussions at this meeting and submit a letter of conformation to PW&T for approval. This confirmation should be obtained prior to the beginning of analysis. Failure to obtain approval for the methodologies, parameters or assumptions used, in the traffic impact study, may result in rejection of the entire study by PW&T.
  Proposed site plans should be submitted to APCD and PW&T as soon as possible. The Public Works and Transportation Division will then coordinate, for APCD, the collection and analysis of all traffic data, by the developer. A representative from APCD will be asked to attend the initial meeting discussed above and will be informed of all meetings, which may affect air quality, throughout the review Process.
  
  No traffic data, however, will be submitted to APCD by the developer. All existing and expected traffic data will be submitted to and review by PW&T. The Public Works and Transportation Division will forward, to APCD, only traffic data required for air quality analysis. Any discussions between the Developer and APCD, concerning site or general traffic related issues, must be coordinated through the Public Works and Transportation Division.
  
  Should any of the proposed development's ingress/egress points be located on a roadway controlled by the Commonwealth of Kentucky, the petitioner is recommended to contact the Kentucky Department of Highway's district office, (District 5). A copy of the proposed development site plan should be submitted to the District Permit Engineer. The District Permit Engineer will be informed of all meetings concerning traffic issues and asked to attend. A copy of the traffic impact study, (both draft and final), report should be submitted to the District Permit Engineer for their review and comment. Proposed mitigation measures, if any, on roadways controlled by the State must be approved by the District Permit Engineer before approval by PW&T will be granted and recommendations to the Planning Commission will be made.
2. Air Quality Analysis
  
  The traffic impact study will generate a substantial amount of data required for the air quality analysis. The traffic data used for the air quality analysis must be identical to that used for traffic analysis. Coordination of all traffic studies shall be the responsibility of PW&T, even in those cases when only an air quality analysis is performed. Upon determination an air quality analysis is required the APCD staff will identify the intersections to be analyzed. These may or may not be the same intersections identified by PW&T for traffic analysis.
  
  Prior to beginning any air quality analysis the petitioner will attend the initial review meeting where APCD staff will be available to discuss the petitioner's air quality analysis plan. At that meeting data collection, analysis techniques, assumptions, and products shall be discussed. The following study elements relative to air quality will be covered:
  1. APCD's certification process for air quality analyst;
  2. Relationship between traffic studies and air quality studies;
  3. Critical intersections included for air quality analysis;
  4. Criteria for locating receptors;
  5. Acceptable air quality model;
  6. Intersection drawing requirements;
  7. Emission rates from MOBILE 5 a;
  8. Traffic counts needed for persistence factor;
  9. Assumptions for meteorological condition;
  10. Background emission levels;
  11. Mitigation of air quality impacts; and
  12. National Ambient Air Quality Standards;
  The guidelines set forth in this document and those discussed at the initial review meeting shall be followed. Any proposed deviation from the guidelines shall be well documented and thoroughly justified in writing prior to their use. Mitigation measures should be developed with consideration given to their effects on traffic and air quality. Although most mitigation measures that improves traffic flow also improves air quality, this is not true for all mitigation measures.
  
  Mitigation measures should be clearly identified and should be implementable. Before a mitigation measure can be accepted there must be a formal enforceable agreement with the party responsible for implementation.
HOW THE IMPACT STUDY WILL BE USED

The Jefferson County Public Works and Transportation Division staff will relate the findings from the traffic impact study to the following:
1. Changes in operating delays, levels of service and volume-to-capacity ratios;
2. Cost of making any necessary improvements to the transportation system;
3. Comparing the impacts of a proposed rezoning with those which would occur by adherence to the Comprehensive Plan;
4. Assessing the necessary capacity of the transportation system in the context of a fully developed impact area; and
5. Improvements proposed by the petitioner to mitigate traffic impacts.
The Air Pollution Control District staff has one major concern: Whether the air quality model predicts an exceedence of the National Ambient Air Quality Standards. Also of concern is the impact on the identified potential "Hot Spots".

Major conclusions reached by the PW&T and APCD will be discussed with the petitioner and incorporated into the staffs' comments and reported to the Louisville and Jefferson County Planning Commission. Three (3) copies of the final study report shall be submitted, by the petitioner, to the Jefferson County Public Works and Transportation Division, two (2) copies to the Air Pollution Control District of Jefferson County, and one (1) copy to the Planning Commission at a minimum of two (2) weeks prior to its Land Development and Transportation (LD&T) Committee, which is held on alternating Thursdays. Where applicable one (1) copy should be submitted to the District permit Engineer at the Kentucky Department of Highways' District 5 Office. Information presented within the final report, backup supporting data and staff comments from PW&T and APCD, will be made available to concerned citizens of Jefferson County requesting this information. A detailed description of the information to be included and a typical outline for the final report is presented in Appendix C. In addition, the study may be used by the PW&T staff to identify needed transportation improvements, right-of-way requirements and the potential for developer contributions to needed improvements. Written commitments regarding these issues may be incorporated, for plan approval, in the form of binding elements by the developer.

Based on this analysis the APCD will make recommendations to the Planning Commission, in regards to the proposed development's impact on air quality. Any negative recommendation must have official approval of the APCD Board. Traffic improvements required to reduce the developments impact on air quality may be identified, with the assistance of PW&T. If these mitigation measure represent sound traffic engineering practices, they may be incorporated into proposed binding elements for the approved plans.

Continued on Next Page >>>