(A) Traffic Impact Analysis required.
(1) A Traffic Impact Analysis (a "TIA") shall be required for all "developments" that would generate 50 peak-hour trips, including the land uses and applicable units, square feet (SF) of gross floor area (GFA) or square feet of gross leased area (GLA), as listed in the following table:
Land Use | 50 Peak-Hour Trips* |
Single Family Home | 48 Units |
Apartments (Low Rise) | 65 Units |
Condominium/Townhouse | |
Mobile Home Park | 87 Units |
Shopping Center (GLA) | 5,400 SF |
Fast Food Restaurant with Drive-In (GFA) | 1,500 SF |
Gas Station with Convenience Store (GFA) | 3 fueling positions |
Banks with Drive-In (GFA) | 2,400 SF |
General Office (GFA) | 23,000 SF |
Medical/Dental Office (GFA) | 13,000 SF |
Research and Development (GFA) | 30,000 SF |
Light Industrial/Warehousing (GFA) | 75,000 SF |
Manufacturing Plant (GFA) | 78,000 SF |
* Rates/equations used to calculate the above thresholds are based on ITE Trip Generation Manual 11th Edition for the PM Peak Hour | |
(2) Any subsequent phase, subdivision, addition, or other form of expansion of any of the types of developments listed above, or any types of development, including those listed above, that generates 50 peak-hour trips when taken cumulatively with previous development shall also require a TIA.
(3) A TIA shall also be required for any project under active development wherein substantial changes have occurred in pertinent conditions existing at the time of approval of such project which would, taken cumulatively, generate 50 peak-hour trips or more.
(4) The City Engineer shall require an update to any TIA if the completion date of any development is delayed for one year or more beyond the completion date anticipated by the original TIA.
(5) The City Engineer may waive the preparation of a TIA or require a traffic statement as opposed to a full TIA if the proposed development is a component of a larger development for which a TIA has recently been prepared for the city or any other regulatory authority and the City Engineer is reasonably certain that the results of a subsequent TIA would duplicate prior findings. The City Engineer may accept a TIA prepared with respect to any development for any other regulatory authority, including Berkeley County or the South Carolina Department of Transportation ("SCDOT"), if the City Engineer determines that such TIA will sufficiently satisfy the requirements and contain the contents required hereby. The City Engineer may require additional components of a TIA if necessitated by special circumstances. Other traffic analysis may be required for any project, if determined by the City Engineer that the project impacts vehicular, bicycle, pedestrian, transit, or other modes of transportation.
(B) Consultant; standards.
(1) A TIA must be prepared by an on-call consultant (the "TIA Consultant") hired by the City of Goose Creek (the "City"). The TIA Consultant shall be an engineer registered in South Carolina that is experienced in the conduct of traffic analyses. The applicant shall pay the cost of any TIA prior to the preparation thereof and reimburse the city for the cost of any outside review of such TIA.
(2) The standards in SCDOT's Access and Roadside Management Standards Manual shall serve as a guide for the TIA. The city will rely upon the most current edition ITE trip generation manual or any alternative acceptable to the city, and available information on land use, travel patterns and traffic conditions.
(C) Traffic Impact Analysis Plan preparation.
(1) Prior to beginning the TIA, the applicant shall supply the city with the following:
(a) A written narrative describing the proposed land use(s), size and projected opening date of the development, including the current phase and all subsequent phases for phased developments;
(b) A site location map showing surrounding development within one-half mile of the property under development consideration; and
(c) A proposed site plan or preliminary subdivision plat illustrating access to public or private roads and connectivity to other contiguous developments, including any possible sight-distance limitations.
(2) After consulting with the SCDOT and Berkeley County, if applicable, the City Engineer will supply to the TIA consultant with the parameters to be followed in the TIA, previously approved but not completed projects, and the intersections to be analyzed along with any associated turning movement counts which are available or discussed and approved by the city. The City Engineer may require that the TIA consider improvements to mitigate and improve the safety and function of multiple transportation modes that may be impacted by traffic generated by the development. These improvements may include, but are not limited to, center medians, sidewalks and/or bicycle accommodations, modifications to ingress and egress points, roadside shoulders, pavement markings, traffic calming and other traffic control devices. The final scope of services and an estimate of the cost of the TIA (the "estimate") shall be submitted to the city for approval.
(3) The applicant shall pay an amount equal to the estimate to the City Engineer, who will deposit the amount in an escrow or special account set up for this purpose. Any funds not used shall be returned to the applicant in a timely manner without interest. The applicant may be required to payadditional costs associated with the TIA if: (i) the applicant substantially amends the application; (ii) additional meetings involving the consultant are requested by the applicant; (iii) the consultant's appearance is requested at Planning Commission or City Council meetings beyond what was anticipated in the scope of services; or (iv) the TIA consultant's's attendance is required at meetings with regional, state, or federal agencies or boards which were not anticipated in the estimate. The applicant must pay all such costs prior to the development plan or plat approval. In the event that the city requires outside review of the TIA, the applicant shall reimburse the city for the cost of any such outside review prior to the issuance of any permit with respect to the development.
(4) All phases of a development are subject to review, and all traffic plans for the entire development shall be integrated with the overall TIA. A TIA for a specific phase of development shall be applicable to the phase of development under immediate review; however, each phase of development shall expand and provide detailed analysis at the development plan stage beyond the estimates provided for at the concept plan or master plan stage. For master-planned and phased developments, the City Engineer may require that a TIA take into account subsequent phases of development that are reasonably knowable. The relative share of the capacity improvements needed shall be broken down as follows: development share, other developments share, any existing over capacity, and capacity available for future growth.
(D) Plan contents.
(1) The following elements shall be included in a TIA:
(a) Study area. Description of the study area including surrounding land uses and expected development in the vicinity that would influence future traffic conditions, including intersections immediately adjacent to the development and other significant intersections identified by the City Engineer. A study area site map showing the site location is required.
(b) Proposed land use. Description of the current and proposed land use including characteristics such as the number and type of units, the gross floor area, and the gross leased area (if applicable), accompanied by a complete project site plan (with buildings identified as to proposed use), and a schedule for construction of the development and proposed development stages.
(c) Existing conditions. Description of existing traffic conditions, adjusted for daily and seasonal variations, including existing AM and PM peak hour traffic volumes adjacent to the site and levels of service for intersections in the study area, and other peak periods as may be determined by the City Engineer. The City Engineer may require that pedestrian counts be taken into consideration. Existing counts may be used if taken within 12 months. In most cases, counts should be taken when school is in session unless otherwise determined by the City Engineer. Other information that may be required may include, but not be limited to, crash data, stopping sight distances, and 50th and 85th percentile speeds.
(d) Future background growth. Estimate of future background traffic growth based on local or statewide growth factors, and considering state, local, or private transportation improvement in the study area that will be underway in the buildout year and traffic that is generated by other proposed developments in the study area, but only with respect to developments with an anticipated completion date that is one year or more from the date of the TIA.
(e) Estimate of trip generation. The site forecasted trips should be based on the most recent edition of the ITE Trip Generation Manual. A table should be provided in the report outlining the categories and quantities of land uses, with the corresponding trip generation rates or equations, and the resulting number of trips. The reason for using the rate or equation should be documented. For large developments that will have multiple phases, the table should be divided based on the trip generation for each phase. Any reductions for any reason should be justified and documented. All trip generation and trip reduction calculations and supporting documentation shall be included in the TIA appendix.
(f) Trip distribution and traffic assignment. The distribution (inbound versus outbound, left turn versus right turn) of the estimated trip generation to the adjacent street network and nearby intersections shall be included in the report and the basis should be explained. The distribution percentages with the corresponding volumes should be provided in a graphical format.
(g) Analysis and estimate of impact. A capacity analysis should be performed at each of the study area intersections and access intersection locations (signalized and unsignalized), including a level-of-service determination for all approaches and movements. Coordination analysis will be required for the signal systems or portion of the signal systems analyzed.
(h) Access management standards. The TIA shall include a map and description of the proposed access including any adjacent driveways and intersections, and a demonstration that the number of driveways proposed is the fewest necessary and that they provide safe and efficient traffic operations.
(i) Traffic signalization. If a traffic signal is being proposed, a signal warrant analysis shall be included in the TIA. The approval of a traffic signal based on projected volumes may be deferred until actual traffic volumes meet warrants given in the MUTCD, in which the developer shall provide funds for the future signal(s) to the city to deposit in an escrow or special account set up for this purpose. The developer should make any laneage improvements during construction so that if in the horizon year a signal is warranted, one may be installed with little impact to the intersection.
(j) Mitigation and alternatives. The average stop time delay in seconds per vehicle for each intersection determined to be critical to the TIA for the proposed development shall be compared to the city's adopted level of service goal of "D" for the average delay for all vehicles at any intersection and all movements and approaches to the intersection during peak hours. Improvements must ensure that the level of service at final buildout, meets or exceeds the level of service at time of approval of the TIA. The TIA should include proposed improvements or access management techniques that will mitigate any significant changes in the levels of service. The City Engineer will be responsible for final determination of mitigation improvements required to be constructed by the applicant.
(E) Traffic Impact Analysis Plan review. The City Engineer shall review all TIAs as part of the initial approval for the concept plan or master plan, and shall coordinate with Berkeley County, the South Carolina Department of Transportation, and other parties the City Engineer deems appropriate. Final TIAs shall be approved at the development plan phase. Following review of the required TIA, the City Engineer shall recommend action as follows:
(1) Approval of the TIA as submitted; or
(2) Approval of the TIA with conditions or modifications as part of the development review and approval process. An acceptable TIA with traffic mitigation measures may include the reduction of the density or intensity of the proposed development; phasing of the proposed development to coincide with state and/or city-programmed transportation improvements; applicant-provided transportation improvements; fees in lieu of construction, or any other reasonable measures to ensure that the adopted traffic level of service goals are met. If mitigation is required, it shall be required by the applicant as a condition of any approval from the city.
(F) Timing, cost of implementation. If traffic mitigation improvements are part of an approved TIA, the improvements shall be completed prior to final plat approval for major subdivisions, or CO issuance for multi-family and non-residential projects. In the alternative, the City Engineer may approve a letter of credit, performance bond, or other means of securing the applicant's obligation to complete improvements. The City Engineer may use his/her best engineering judgement to determine the most effective solution. The costs of implementation of an approved mitigation program shall be the responsibility of the applicant. No certificates of zoning compliance or building permits shall be issued unless provisions of the TIA are met.
(G) Responsibility. The City Engineer shall have the primary responsibility to administer the provisions of this section. The City Engineer may delegate any responsibility hereunder to any qualified city staff person or any outside consultant, subject to final approval by the City Engineer.
(Ord. 2023-017, passed 6-13-2023)