Skip to code content (skip section selection)
The purpose of a transportation impact analysis (TIA) is to assess the impact of a proposed development on the existing transportation system. A TIA will (1) ensure that the transportation network has adequate capacity to handle projected transportation demand associated with the project, (2) identify problems with the transportation system, (3) delineate solutions to identified problems, and (4) identify improvements to be incorporated into the proposed development.
(A) Required. Applicants for development authorization in which the proposed development, redevelopment, or change of use is expected to generate 100 or more peak-hour trips (a.m. or p.m.) or 1,000 or more trips daily shall have prepared by a qualified professional a TIA meeting the guidelines established in this section. In addition to the foregoing, the Planning Director shall have the discretion to require a TIA when there are localized safety or capacity deficiencies.
(B) Presubmittal conference. An applicant for development authorization for any project expected to meet or exceed one or both of the TIA thresholds specified in division (A), above, shall schedule a presubmittal conference with the town. The engineering firm selected to prepare the TIA shall attend this meeting the purpose of which is to establish the study area, the trip distribution, the traffic counts to be utilized, approved developments in the area, pass-by and internal capture percentages, additional hours of analysis, if required (other than a.m. or p.m. peak), and resolve any other questions specific to the site.
(C) TIA submission. Three copies of the TIA, if required, shall accompany the application for development authorization. The TIA shall be prepared by a licensed engineer registered to practice in the State of North Carolina who shall have traffic assessment and transportation management experience. At a minimum, the TIA shall include the following:
(1) Study purpose and objectives.
(2) Description of the site and study area boundaries including appropriate mapping and rationale for selection of the study area boundaries.
(3) A summary of existing conditions including, but not limited to, surrounding street and key intersection traffic volumes (daily and peak-hour), turning movements, capacities, safety deficiencies, and funded transportation improvements.
(4) Anticipated or approved development in the area.
(5) Trip generation, trip distribution, and discussion of the following:
(a) Trip generation rates shall be based on trip generation rates contained in the latest edition of Trip Generation published by the Institute of Transportation Engineers (ITE). The applicant shall also provide the ITE code used to identify the development trip generation rate and assumptions used or data collected for any variations from generally accepted ITE rates or equations.
(b) Pass-by trip factors and assumptions.
(c) Internal trip assumptions for mixed use developments.
(d) Trip distribution assumptions.
(6) Projection of future traffic volumes and assessment of future roadway and intersection operating conditions for the year of the ultimate completion of the project. All projections should specifically document projected background traffic as well as the traffic generated by the proposed development. If the project is to be phased; projections for each phase of the development is required. If the unphased build-out period of the project is greater than nine years, then a minimum of one intermediate and one full build-out projection is required. All projections and assessments should include the following three scenarios:
(a) No build.
(b) Maximum possible development under existing use or zoning. Applicant shall conduct assessment of project phasing. The impact of the development of a particular phase is not to be compared with the total possible build-out of the entire project location.
(c) The development as proposed.
(7) Analysis of the key elements of the development and evaluation of the impacts of the development on the following:
(a) Generalized peak hour and/or daily Link Level of Service (LOS) analysis. Using the peak hour directional volumes and daily traffic volumes forecast and service thresholds, a general evaluation shall be made of the street system for the short term and long-term horizon years. If the project is to be phased; then an assessment of conditions after the completion of each phase of the development is required. Incremental differences attributable to the land use action shall be identified. A map showing generalized levels of service shall be presented for each design year.
(b) Access analysis. The deign, number, and location of access points to collector and arterial roadways must be fully analyzed. The number of access points shall be kept to a minimum and be designed to be consistent with the type of roadway facility. Access analysis shall include a strip accident, intersection accident analysis and bicycle/ pedestrian analysis.
(c) Intersection analysis (signal warrant analysis, phasing analysis, intersection crash analysis and progression analysis). The appropriateness of the development’s access locations and type must be established. For full-access locations, a signal warrant analysis based on the Manual on Uniform Traffic Control Devices must be conducted for each design year. Traffic signals specifically warranted by the land use action shall be identified.
(d) Peak hour intersection level of service. An a.m. and p.m. peak hour intersection level of service analysis shall be conducted for each intersection, based on procedures specified in the most recent release of the Highway Capacity Manual. Levels of service for signalized intersections shall be based on the signal timings developed for the signal progression analysis.
(e) Turn lane storage requirements. Turn lane storage needs shall be identified for the “warranted” situation, based on projected turning volumes and AASHTO analytic techniques. Appropriate documentation of the calculations must be provided.
(f) Sight distance. The identification of sight distance at the development entrances and all internal streets shall be conducted.
(g) Appropriateness of acceleration or deceleration lanes. All proposed development access points on arterials shall be evaluated to determine the need for acceleration lanes or deceleration lanes, with justification and basis provided for recommendations.
(h) Pedestrian and bicycle analysis. Continuity and adequacy of pedestrian and bike facilities shall be provided to the nearest attraction (exiting or planned) within 1/4 mile of the development site. Destinations of significance include bus stops, elementary schools, parks, activity centers and major bicycle facilities. Adherence to the Americans with Disabilities Act (ADA) shall be required.
(i) Public transportation analysis. Existing and proposed (if any) public transportation facilities analysis shall be provided.
(j) Special analysis/issues. The town may require specific focused traffic analyses relative to the proposed development.
(8) Recommendations for site access and transportation improvements or mitigation measures needed to maintain traffic flow to, from, within and adjacent to the proposed development at an acceptable and safe level of service (generally assumed at LOS D or better). Any recommendations for roadway improvements should identify funding sources for these improvements.
(9) Data collected for the study shall be made available to the town for evaluation of the study conclusions. The format for date submission as well as format for data to be provided to the town will be determined at a pre-consultation meeting between the applicant and the town.
(Ord. passed 10-1-07)