Borough of Denver, PA Article VII Traffic Impact Studies

§ 170-41 Purpose.

A. Whenever a proposed project will generate 100 new vehicle trips in the peak direction (inbound or outbound) during the site peak traffic hour, the applicant shall perform a traffic impact study. Based on this study, certain improvements may be identified to provide safe and efficient access to the development.

B. In addition, a traffic impact study shall be prepared whenever either one of the following conditions exist within the impact study area:

(1) Traffic study required. A traffic impact study shall be required for developments or subdivisions that meet any of the following criteria.

(a) Residential: 25 or more dwelling units.

(b) Commercial: 10,000 or more square feet of gross floor area.

(c) Industrial: 25,000 or more square feet of gross floor area.

(d) Any proposed use or combination of uses that is projected to generate 300 or more vehicle trips per day.

(e) Current traffic problems exist in the local area, such as a high-accident location, confusing intersection, or a congested intersection which directly affects access to the development.

(f) The ability of the existing, roadway system to handle increased traffic, or the feasibility of improving the roadway system to handle increased traffic is limited.

§ 170-42 Traffic impact study.

A. Area of traffic impact study. The ultimate scope of the traffic impact area (TIA) will be subject to the approval of the Borough Engineer and projected scopes shall be submitted for review prior to collection of traffic count data. At a minimum, the TIA shall include all streets and major intersections within a 1/2 mile radius of each access for the proposed development. If a street abutting the proposed development does not contain an intersection with another street within the 1/2 mile area, the first intersection with such abutting street shall be included. Whenever a proposed project will generate 100 new vehicle trips in the peak direction (inbound or outbound) during the site peak or adjacent street peak hours, the traffic impact area shall include, at a minimum, all streets and major intersections within a one mile radius.

B. Preparation by transportation engineer required. Traffic impact studies shall be prepared under the supervision of qualified and experienced transportation engineers with specific training in traffic and transportation engineering and at least two years of experience related to preparing traffic studies for existing or proposed developments.

C. Horizon year. The traffic forecasts shall be prepared for the anticipated opening year of the development, assuming full buildout and occupancy. This year shall be referred to as the "horizon year" in the remainder of this chapter.

D. Non-site traffic estimates.

(1) Estimates of non-site traffic shall be made, and will consist of through traffic and traffic generated by all other developments within the study area for which preliminary or final plans have been approved.

(2) Non-site traffic may be estimated using any one of the following three methods: "Build-up" technique, area transportation plan data or modeled volumes, and trends or growth rates.

E. Trip generation rates required. The traffic impact study report shall include a table showing the categories and quantities of land uses, with the corresponding trip generation rates or equations (with justification for selection of one or the other), and resulting number of trips. The trip generation rates used must be either from the latest edition of Trip Generation by ITE, or from a local study of corresponding land uses and quantities. All sources must be referenced in the study.

F. Consideration of pass-by trips. If pass-by trips or shared trips are a major consideration for the land use in question, studies and interviews at similar land uses must be conducted or referenced.

G. Rate sums. Any significant difference between the sums of single-use rates and proposed mixed-use estimates must be justified in the study report.

H. Explanations required. The reasoning and data used in developing a trip generation rate for special/unusual generators must be justified and explained in the report.

I. Definition of influence area.

(1) Prior to trip distribution of site-generated trips, an influence area must be defined which contains 80% or more of the trip ends that will be attracted to the development. A market study can be used to establish the limits of an influence area, if available. If no market study is available, an influence area should be estimated based on a reasonable documented estimate. The influence area can also be based on a reasonable maximum convenient travel time to the site, or delineating area boundaries based on locations of competing developments.

(2) Other methods such as using trip data from an existing development with similar characteristics or using an existing origin-destination survey of trips within the area can be used in place of the influence area to delineate the boundaries of the impact.

J. Estimates of trip distribution required.

(1) Trip distribution can be estimated using any one of the following three methods:

(a) Analogy.

(b) Trip distribution model.

(c) Surrogate data.

(2) Whichever method is used, trip distribution must be estimated and analyzed for the horizon year. A multiuse development may require more than one distribution and coinciding assignment for each phase (for example, residential and retail phases on the same site). Consideration must also be given to whether inbound and outbound trips will have similar distributions.

K. Trip assignments.

(1) Assignments must be made considering logical routings, available roadway capacities, left turns at critical intersections, and projected (and perceived) minimum travel times. In addition, multiple paths should often be assigned between origins and destinations to achieve realistic estimates rather than assigning all of the trips to the route with the shortest travel time. The assignments must be carried through the external site access points and in large projects (those producing 500 or more additional peak direction trips to or from the site during the development's peak hour) through the internal roadways. When the site has more than one access drive, logical routing and possibly multiple paths should be used to obtain realistic driveway volumes. The assignment should reflect conditions at the time of the analysis. Assignments can be accomplished either manually or with applicable computer models.

(2) If a thorough analysis is required to account for pass-by trips, the following procedure should be used:

(a) Determine the percentage of pass-by trips in the total trips generated.

(b) Estimate a trip distribution for the pass-by trips.

(c) Perform two separate trip assignments, based on the new and pass-by trip distributions.

(d) Combine the pass-by and new trip assignment.

(3) Upon completion of the initial site traffic assignment, the results should be reviewed to see if the volumes appear logical given characteristics of the road system and trip distribution. Adjustments should be made if the initial results do not appear to be logical or reasonable.

L. Total traffic impacts. Traffic estimates for any site with current traffic activity must reflect not only new traffic associated with the site's redevelopment, but also the trips subtracted from the traffic stream because of the removal of a land use. The traffic impact report should clearly depict the total traffic estimate and its components.

M. Capacity analysis.

(1) Capacity analysis must be performed at each of the major street and project site access intersection locations (signalized and unsignalized) within the study area. In addition, analyses must be completed for roadway segments, deemed sensitive to site traffic within the study area. These may include such segments as weaving sections, ramps, internal site roadways, parking facility access points, and reservoirs for vehicles queuing off site and on site. Other locations may be deemed appropriate depending on the situation.

(2) The recommended level-of-service analysis procedures detailed in the most recent edition of the Highway Capacity Manual shall be followed. The Borough Council considers the overall level-of-service ratings A, B, C and D to be acceptable for signalized intersections (Levels C or better are considered desirable); level-of-service E or F is considered to be unacceptable.

(3) The operational analyses in the Highway Capacity Manual should be used for analyzing existing conditions, traffic impacts, access requirements, or other future conditions for which traffic, geometric, and control parameters can be established. Other methods of operational analysis, such as synchro analysis package may be acceptable, subject to the approval of the Borough Engineer.

N. Required levels of service. The recommendations of the traffic impact study shall provide safe and efficient movement of traffic to and from and within and past the proposed development, while minimizing the impact to non-site trips. The current levels of service must be maintained if they are C or D, not allowed to deteriorate to worse than C if they are currently A or B, and improved to D if they are E or F.

O. Documentation required. A traffic impact study report shall be prepared to document the purpose, procedures, findings, conclusions, and recommendations of the study.

(1) The documentation for a traffic impact study shall include, at a minimum:

(a) Study purpose and objectives.

(b) Description of the site and study area.

(c) Existing conditions in the area of the development.

(d) Recorded or approved nearby development.

(e) Trip generation, trip distribution, and modal split.

(f) Projected future traffic volumes.

(g) An assessment of the change in roadway operating conditions resulting from the development traffic.

(h) Recommendations for site access and transportation improvements needed to maintain traffic flow to, from, within, and past the site at an acceptable and safe level of service.

(2) The analysis shall be presented in a straight forward and logical sequence. It shall lead the reader step-by-step through the various stages of the process and resulting conclusions and recommendations.

(3) The recommendations shall specify the time period within which the improvements should be made (particularly if the improvements are associated with various phases of the development construction), and any monitoring of operating conditions and improvements that may be required.

(4) Data shall be presented in tables, graphs, maps, and diagrams wherever possible for clarity and ease of review.

(5) To facilitate examination by the Borough Council, an executive summary of one or two pages shall be provided, concisely summarizing the purpose, conclusions, and recommendations.

(6) The report documentation outlined above provides a framework for site traffic access/impact study reports. Some studies will be easily documented using this outline. However, the specific issues to be addressed, local study requirements, and the study results may warrant additional sections.

P. Contribution in lieu of preparation of studies.

(1) If an applicant believes that the preparation of a traffic study and report required herein is not warranted, he may request the Borough Council to waive the preparation of such study.

(a) For approval of any commercial, industrial, or institutional subdivision or land development, the applicant shall provide the Borough with a certification of the usable building floor area to be constructed for the purpose of determining the contribution in lieu of preparation of studies.

(b) The contribution in lieu of preparation of studies provided for herein shall be in addition to all other review, inspection, and other fees or charges imposed by the Borough, and all sums otherwise agreed to be paid by the applicant.

(c) The applicant shall enter into an agreement with the Borough setting forth the contribution in lieu of preparation of studies to be paid and the studies to be waived by the Borough. All such agreements shall be in a form satisfactory to the Borough Solicitor.

(d) All contributions in lieu of preparations of fees shall be paid prior to approval of the final plan by the Borough Council.

(e) All developments receiving a waiver of preparation of a traffic evaluation study in accordance with this section shall provide, as a minimum, the following information:

(2) Trip generation. Identify the amount of traffic generated by the site for daily and three peak hour conditions (AM, PM, and site generated). The trip generation rates shall be justified and documented to the satisfaction of the Borough.

§ 170-43 Improvements.

A. Responsibility for improvements.

(1) The applicant shall be responsible for the improvements required to provide safe and convenient ingress and egress to the development site.

(2) Where the Traffic Impact Study indicates that improvements are necessary or advisable to existing Borough and/or state streets and/or intersections within the Traffic Impact Study area in order (i) to assure adequate, safe and convenient access to each lot and/or structure and/or parking compound proposed as part of the development of the tract, (ii) to accommodate the traffic due to the proposed development, (iii) to provide for a level of service and delay for the design year, or years for phased projects, with the development which is at least equivalent to the projected level of service and delay for the design year(s) without the proposed subdivision or development, and/or (iv) to preserve the existing convenience of access to or ability to exit from abutting properties which gain access from the existing street, the developer shall install all such indicated improvements. The developer shall install additional traffic lanes, traffic dividers, traffic control devices, traffic signals, and other measures as appropriate to ensure that the development of the tract does not adversely impact the existing street system and/or access to or the ability to exit from properties gaining access from an affected street.

(3) If the Traffic Impact Study indicates that improvements must be made to a state street, the developer shall also take all action necessary to obtain any Pennsylvania Department of Transportation permits and/or approvals to install the necessary street widening and/or traffic signals or traffic control devices. If the Traffic Impact Study recommends installation of traffic signals or traffic signal modifications, the developer shall prepare all studies and submit all necessary applications to enable the installation of the traffic signal or modifications and shall install the traffic signal or modifications at their cost and expense.

(4) If the Traffic Impact Study indicates that traffic control devices or regulations, including but not limited to stop intersections, speed limit reductions, or parking prohibitions, are required, the developer shall prepare all studies necessary to justify imposition of such regulations in accordance with Pennsylvania Department of Transportation regulations and shall pay all costs associated with the preparation and enactment of an ordinance to establish such regulations.

(a) The developer shall bear all costs and expenses in connection with the improvements required by this § 170-43A. If the developer requires the Borough to submit any permit applications or requests for approvals in the name of the Borough, the developer shall reimburse the Borough for all costs and expenses incurred by the Borough in connection with its review of the application and submission of the application to the Pennsylvania Department of Transportation or any other governmental agency.

(b) When the Borough Council determines that the required improvements are not feasible at the present time, the developer shall deposit funds with the Borough in the amount of 110% of the cost of the improvements computed in accordance with the provisions of Section 509 of the Municipalities Planning Code.[1] Such funds shall be maintained by the Borough in a general account to be used for traffic improvements. The developer may request a modification to reduce the amount of funds to be deposited with the Borough under this provision. In order to warrant the granting of such modification, the developer shall make application to the Borough Council in accordance with Article IX. The developer shall establish the particular circumstances which are applicable to the development and shall demonstrate good cause for such modification. The Borough Engineer shall make a recommendation to the Borough Council whether or not and to what extent such requested modification should be granted.

[1] Editor's Note: See 53 P.S. § 10509.

B. Coordination with Borough requirements. The applicant shall be responsible for other improvements as may be agreed to with the Borough Council or which are required by any Borough impact fee ordinance to be installed or paid for by the applicant consistent with provisions of Article V-A of the Pennsylvania Municipalities Planning Code, Act 247 of 1968, as amended.

§ 170-44 Specific traffic control and access requirements.

The following specific traffic control and access requirements shall be met for developments that produce 100 peak hour directional trips.

A. If any traffic signals are to be installed, the distance between any new and/or existing signals shall be at least 1,000 feet unless it can be demonstrated that adjacent traffic signals can operate sufficiently at lesser distances.

B. Design of proposed development access points shall take into consideration the horizontal and vertical grades of the existing road network in the traffic impact study area to permit safe and convenient access to the site as defined in the latest Pennsylvania Department of Transportation standards and regulations. All modifications required to meet these regulations will be the responsibility of the developer.

C. The developer shall demonstrate by using the latest Pennsylvania Department of Transportation standards and regulations that the proposed use will not create traffic patterns and movements that will jeopardize the traveling public.

(1) Stacking of sufficient length shall be provided in all traffic lanes on the site and off the site on adjacent roadways to insure that there shall be no blockage of through traffic. The design and length of the stacking lanes shall be justified and supported by the queuing analysis required as part of the traffic impact study.

(2) Street and/or access drives to and within the site shall be designed in a manner that blockage of through traffic by vehicles attempting to enter or exit on these streets or access drives will not occur.

(3) Acceleration, deceleration and turning lanes shall be of sufficient lengths to accomplish their intended use.

D. If reduction of the speed limit, installation of traffic control devices, limitation of parking or turning movements or similar measures are required to mitigate traffic impacts upon Borough or state highways, the applicant shall present traffic studies performed in accordance with Pennsylvania Department of Transportation regulations and Publication No. 201, Engineering and Traffic Study Regulations. The erection or the installation of such traffic control devices shall be in accordance with Title 67, Chapter 211, Official Traffic Control Devices, of Pennsylvania Department of Transportation regulations. If the enactment of an ordinance is necessary to effectuate the traffic regulations or the installation of the traffic control device, the applicant shall reimburse the Borough for all expenses in the preparation and enactment of the necessary ordinance.

E. No street shall be located in a manner which would limit access to or exiting from abutting properties gaining access from the existing street with which a proposed street will intersect unless the developer provides such lots with alternate access from the proposed street system in a manner acceptable to each affected lot owner. It shall be the burden of the applicant to demonstrate that such access is acceptable to all owners of an affected lot. For the purpose of this provision, limitation of access shall include the limitation of turning movements into or exiting the abutting property or properties gaining access from the existing street, whether by traffic regulations, installation of barriers to prevent turning movements, installation of additional traffic lanes in front of a property, or difficulties or delays resulting from increased traffic flows.

F. Where new intersections are being established to serve as access to the proposed development, these intersections must be designed to at least operate at Level of Service C or better.

G. For access points to the proposed development and any major intersections where traffic signal control may be required or is being proposed, a traffic signal warrant analysis shall be performed in accordance with the requirements of Pennsylvania Department of Transportation Publication 201. A left turn lane shall be provided and an analysis shall be completed to determine the type of signal phasing required.

H. Emergency traffic signal preemption shall be addressed and provided as required.

I. Additional left and right turning lanes shall be provided to address the existing roadway site conditions and access to the proposed development.

J. An agreement between the Borough Council and Developer shall be provided with regard to operating expenses and maintenance of proposed traffic signals.

K. Additional through lanes and lane transitions of sufficient length shall be provided to allow smooth traffic flow to existing traffic lanes thus minimizing congestion, delays and or blockage of through traffic within the proposed improvement area. The design and length should be justified and supported by the queuing analysis required as part of the traffic impact study.

L. Sidewalks shall be provided along the property frontage and within the development.