(A) Applicability. A traffic impact study shall be required with applications for zoning map amendments, preliminary plats, and planned developments that are projected to generate 20 or more peak hour vehicle trips, based on trip generation rates from the latest edition of the Institute of Transportation Engineers trip generation manual. The Planning or Public Works Director shall also be authorized to require traffic impact studies when it is determined that a proposed development is likely to have a significant impact on transportation capacity, transportation levels of service, or traffic safety in the vicinity of the proposed development.
(B) Study scope. When a traffic impact study is required, the type and scope of the study shall be determined during a scoping meeting with the Planning and Public Works Directors. The meeting may also involve representatives of or request assessments from other agencies and departments. The elements to be determined during the scoping session shall include:
(1) Type of study. The possible types of reports include: a letter report, full traffic impact analysis report, or special report (e.g., sight distance survey);
(2) Definition of impact area. The points of access and key streets and intersections that may be affected by development of the subject tract constitute the impact area. Traffic recorder and turning movement assessment locations shall be determined;
(3) Period of analysis. Periods of analysis may include: daily traffic, a.m., p.m., or weekend peak hour;
(4) Analysis scenarios. Scenarios for analysis include: existing conditions, opening year conditions with and without development, and ten years after opening with and without development;
(5) Process. Process for determining trip generation and distribution including: trip generation category, diversion assumptions, and distribution assumptions;
(6) Growth rate assumption. The rate of growth assumed in background traffic assumptions; and
(7) Pipeline development. Developments in the area that have been approved or are under review.
(C) Traffic study elements. A letter report or special report shall include those elements agreed upon in the scoping meeting. A full traffic study shall include the following elements.
(1) Existing condition survey.
(a) Street system description. The street system shall be described including geometric features, lane usage, traffic control, signage, sight distances and adjacent uses, and curb cuts.
(b) Traffic volumes. Existing traffic volumes shall be provided for the impact area including both AADT (average annual daily traffic) and “design” peak hour volumes. AADT may be derived from current counts of the State Department of Transportation (if available) and peak hour volumes shall be determined from field counts. Data shall be adjusted for daily and seasonal variations. Turning movement counts for the peak hour shall be provided for critical intersections. Peak hour periods shall be as determined at the scoping meeting.
(c) Capacity analysis. Existing capacity of signalized and unsignalized intersections.
(d) Other. Other items may be required at the discretion of the Public Works Director depending upon the type and scale of the project. These may include, but are not limited to: queue length analysis, pedestrian counts, accident data, traffic speeds (both fiftieth and eighty-fifth percentile) and stopping sight distance.
(2) Future without development. Capacity analysis is to be provided for opening year and plus ten-year for key intersections (and roadway segments where appropriate) without the development but including any planned developments. The analysis shall be based upon the Highway Capacity Manual or other methodologies approved in advance by the Public Works Director.
(3) Future with development.
(a) Projection of the daily and peak hour traffic generation of the project shall be made using the latest edition of the Institute of Transportation Engineers trip generation manual unless the Public Works Director determines that locally derived data will provide more accurate forecasts. Data from similar facilities may be used where the information is not available from the Institute of Transportation Engineers.
(b) The projected trips shall be distributed onto the road network as agreed in the scoping meeting.
(c) Capacity analysis for opening year and plus ten-year for key intersections (and roadway segments where appropriate.
(d) Special analysis as may be required to determine warrants for signalization, minimum safe sight distances, gap analysis, turning radius requirements, queue length analysis, turning lane length analysis, curb cut locations, or similar requirements.
(4) Mitigation plan. Where the analysis indicates that the project will create deficiencies in the impact area, improvements shall be recommended which shall include projected cost estimates. The design of improvements shall be in accordance with specifications of the Public Works Director and, where appropriate, the State Department of Transportation. Where a decision-making body determines that a mitigation plan is not adequate to address the traffic impacts of the project, it may serve as a basis for denial of the rezoning, preliminary plat, or planned development request.
(5) Consultants. The Public Works Director may require that a mutually agreed upon independent consultant be hired by the town to perform required traffic impact studies or to review all or part of a study prepared by the applicant’s consultants. The Public Works Director is authorized to administer the contract for such consultants.
(a) The Public Works Director shall determine the scope of services to be performed by the independent consultant and receive a cost estimate of such services.
(b) The applicant shall provide an amount equal to the estimate to the Public Works Director, who will deposit the amount in an escrow or special account set up for this purpose. Any funds not used for the independent consultant shall be returned to the applicant in a timely manner without interest.
(c) The Public Works Director may require additional fees for the independent review if: the decision-making body expands the scope of the required review; the applicant substantially amends the application; additional meetings involving the consultants are requested by the applicant; the consultant’s appearance is requested at Planning Commission or Town Council meetings beyond what was initially anticipated; or the consultant’s attendance is required at meetings with regional, state, or federal agencies or boards which were not anticipated in the earlier scope of services.
(Ord. 2012-06, § 9.9, passed 10-18-2012; Ord. 2013-07, passed 10-17-2013)