(A) Generally. Any development shall have an adequate off-site street and thoroughfare system that:
(1) Provides for streets in an appropriate location, of suitable design and width, and with appropriate traffic control devices to accommodate existing traffic, traffic anticipated from the development, and traffic anticipated from other developments impacting the same streets;
(2) Affords satisfactory access to adjoining properties; and
(3) Accommodates police, firefighting, sanitation, and street maintenance equipment.
(B) Access required. The subdivider shall acquire right-of-way and necessary easements for the construction of any off-site streets necessary to connect the subdivision with an adequate off-site street network.
(1) Any development with five or more lots shall have access to a collector or major thoroughfare on a paved street with a design speed of 30 miles per hour.
(2) If existing streets do not provide access, the developer shall do one of the following:
(a) Construct a new street which includes:
1. Acquisition and dedication of adequate right-of-way;
2. Designing the street in accordance with the street design criteria of § 154.080; and
3. Constructing the street in accordance with the city standard street specifications.
(b) Improve existing streets which includes:
1. An engineer's design to determine what work is required to improve the existing street for a design speed of 30 miles per hour;
2. Submitting the engineer's design to the City Engineer for approval; and
3. Constructing the required improvements in accordance with the approved design and the city standard street specifications.
(C) Adequacy required. Before plat approval and in conjunction with the rough proportionality determination under § 154.028, the City Engineer shall determine whether the existing or proposed roadway network, including perimeter streets, which will serve the subdivision has adequate capacity to accommodate existing traffic, traffic reasonably anticipated from the subdivision, and traffic reasonably anticipated from other developments approved or to be approved within a reasonable period. The city's determination shall be based on information provided by the applicant and applicant's engineer in the plat application and any supporting studies.
(D) Traffic study, traffic impact analysis, and mitigation.
(1) Purpose. A traffic study and a traffic impact analysis (TIA) is intended to adequately assess the traffic-related impacts of a zoning and/or development proposal on the existing and planned thoroughfare system. The purpose of this division is to:
(a) Provide the safest and most efficient transportation system in conjunction with the development review process;
(b) Inform the applicant of the city’s requirements and expectations;
(c) Provide standard guidelines for the preparation and review of a traffic study and a traffic impact analysis (TIA); and
(d) Establish equitable mitigation measures for the accommodation of identified impacts.
(2) Applicability of requirements.
(a) A traffic study is required for zoning requests when:
1. The proposed zoning request will generate over 50 trips during the peak hour; or
2. The proposed zoning request will generate over 500 trips per day for residential traffic; or
3. The proposed zoning request will generate over 1,000 trips per day for commercial traffic.
(b) A traffic impact analysis (TIA) is required for all plats when:
1. The proposed subdivision consists of 100 or more dwelling units.
2. The proposed subdivision generates over 100 trips during peak hours.
3. The proposed subdivision generates over 1,000 trips per day.
(c) Special circumstances. A traffic study and traffic impact analysis (TIA) may also be required for zoning and development applications if one or more of the following conditions exist:
1. City Council determines that additional information beyond the required submittals is needed to determine the impacts of the proposed development on the transportation system.
2. Traffic generated from a non-residential development will significantly impact adjacent residential neighborhoods.
3. Traffic operational impacts such as conflicts with driveways, left or right turns, signal timing, median openings or sight distance are anticipated. In such cases the study will only be required to answer questions related to the specific impacts.
4. Existing traffic conflicts on adjacent streets are expected to worsen due to traffic generated from the new development.
5. Implementation of the Master Thoroughfare Plan in the area will not occur prior to development of the property.
6. The proposed land use differs significantly from that contemplated in the adopted Comprehensive Plan.
7. The internal street or access system is not anticipated to accommodate the expected traffic generation.
(3) Study submission requirements.
(a) Timing of submittals. If required, a study shall be submitted to the city in accordance with the following:
1. Zoning cases. The traffic study shall be submitted no later than the submission of the zoning case application.
2. Subdivision plats. The traffic impact analysis (TIA) shall be submitted no later than the submission of the first plat application.
(b) Content requirements. The traffic study and the traffic impact analysis for zoning and development applications shall comply with the following methodology and be formatted as outlined in this section.
1. Traffic study.
a. Site location/study area. A brief description of the size, general features, and location of the site, including a map of the site in relation to the study area and surrounding vicinity;
b. Proposed zoning/site development. A description of the proposed zoning/development for the site, including land area by zoning classification and density, square footage and number of dwelling units (as appropriate);
c. Existing site trip generation. A table displaying trip generation rates and total trips generated by land use category for the A.M. and P.M. peak hours and on a daily basis, assuming full development and occupancy based on existing zoning (if applicable);
d. Proposed site trip generation. A table displaying trip generation rates and total trips generated by land use category for the A.M. and P.M. peak hours and on a daily basis, assuming full development and occupancy for the proposed development. The city's standard for trip generation rates for various land use categories shall be those found in the latest edition of Trip Generation published by the Institute of Transportation Engineers (ITE) or other published or recognized sources applicable to the region;
e. Net change in trip generation (zoning). Possible trip generation minus existing trip generation and proposed trip generation minus existing trip generation (if applicable);
2. Traffic impact analysis (TIA) shall be prepared under the direction of an engineer with experience in transportation engineering and shall include:
a. All requirements of a traffic study;
b. Existing zoning. A description of the existing zoning for the site and adjacent property, including land area by zoning classification and density, square footage the number of dwelling units (as appropriate);
c. Existing development. A description of any existing development on the site and adjacent to the site and how it would be affected by the development proposal;
d. Thoroughfare system. A description and map of existing planned or proposed thoroughfares and traffic signals for horizon year(s) within the study area;
e. Existing traffic volumes. Recent traffic counts for existing thoroughfares and major intersections within the study area;
f. Projected traffic volumes. Horizon year(s) background traffic projections for the planned thoroughfare system within the study area;
g. Trip distribution and traffic assignment. Tables and figures of trips generated by the proposed development (or net change in trips, if applicable) added to the existing and projected volumes, as appropriate, with distribution and assignment assumptions;
h. Level of service evaluations. Capacity analyses for weekday A.M. and P.M. peak hours of the roadway and peak hour of the site, if different from the roadway, for both existing conditions and horizon year projections for intersections, thoroughfare links, median openings and turn lanes associated with the site, as applicable. The minimum acceptable level of service (LOS) within the city shall be defined as LOS "C" in peak hours for all critical movements and links. All development impacts on both thoroughfare and intersection operations must be measured against this standard;
i. Traffic signal evaluations. The need for new signals based on warrants, the impact on transportation system performance;
j. Evaluation of proposed/necessary mitigation. Capacity analyses for weekday A.M. and P.M. peak hours of the roadway and peak hour of the site, if different from the roadway, for intersections, thoroughfare links, median openings and turn lanes associated with the site under proposed/necessary traffic mitigation measures;
k. Conclusions. Identification of all thoroughfares, driveways, intersections, and individual movements that exceed LOS D, degrade by one or more LOS, the percentage of roadway volume change produced by the proposed development, and any operational problems likely to occur;
l. Recommendations. Proposed impact mitigation measures consistent with this section; and
m. Other information required for proper review. As requested by the city's Director of Public Works or designated representative.
(c) Report format. The various sections of the report should be categorized according to the subject areas below:
1. Traffic study.
a. Introduction (site location, proposed development).
b. Trip generation table (including existing trip generation, proposed trip generation, net change).
2. Traffic impact analysis (TIA).
a. Executive summary (key findings, recommendations).
b. Introduction (proposed development, study purpose, and methodology).
c. Existing conditions (study area roadway network, adjacent roadway classifications, existing land use, existing traffic volumes, analysis of existing conditions, project specific conditions).
d. Trip generation and distribution (proposed development, trip generation, adjusted trips, trip distribution).
e. Pre and post development comparative analysis (background traffic conditions, background levels of service, built traffic conditions, built levels of service, total traffic with mitigation measures – levels of service).
f. Conclusions (expand on executive summary, key findings, recommendations).
g. List of all tables.
h. List of all figures.
i. Appendices.
(4) Mitigation. Mitigation of impacts identified during a traffic impact analysis (TIA) shall be required when the proposed development would cause a facility or traffic movement to fall below a LOS C, or the traffic facility or movement is already is below a LOS C and the development would contribute 5% or more of the total traffic during built conditions, or the traffic impact analysis (TIA) recommends mitigation measures. If mitigation is required, the applicant must mitigate the impact of the proposed development, and would not be responsible for alleviating any deficiencies in the thoroughfare system that may occur without the proposed development. Acceptable mitigation measures include but are not limited to:
(a) Staging of development in order to relate site development to the construction of the required thoroughfare system;
(b) Off-site improvements, including the provision of right-of-way and/or the participation in funding for needed thoroughfare and intersection improvement projects; and
(c) On-site improvements, including access controls and site circulation adjustments.
(E) Effect of adequacy determination. If this section requires the submission of a traffic study and the adequacy determination for roadways indicates that the off-site roadway network serving the proposed subdivision is inadequate, the subdivider shall execute a community facilities agreement with the city to ensure the roadways are adequate to accommodate the impacts of the subdivision. The agreement may include a joint participation agreement under § 154.063 or an escrow of funds for future construction under § 154.065.
(F) Phasing. If the property to be developed is intended as a phase in a larger subdivision or constitutes a portion of the property to be ultimately developed, the city may require a demonstration of adequacy for additional phases as a condition of approval of the proposed plat.
('68 Code, App. B, § 5.10) (Ord. 8-1989-34, passed 8-8-89; Am. Ord. 06-2019-32, passed 6-11-19; Am. Ord. 08-2023-60, passed 8-22-23)