The intent of a traffic impact study is to identify and plan
for safe means of ingress and egress for proposed developments; to
understand the adequacy of the existing transportation network for
the intended use; to identify any potential transportation impacts
of the proposed subdivision and/or land development; and to determine
any roadway or traffic signalization improvements necessary to mitigate
any impacts resulting from the planned development.
The study shall be prepared in accordance with the Institute
of Transportation Engineer's (ITE) Traffic Engineering Handbook
an ITE's Transportation Impact Analyses for Site Development,
current editions, and PennDOT Publications 212 and 282, current editions,
and the requirements contained herein.
A. General Site Description.
(1)
The site description shall include the size, location,
existing and proposed land uses, current zoning, construction phasing,
and completion date of the proposed land development. Any residual
land which, when developed, will utilize the proposed improvements
shall be planned for as the highest and best use for the residual
property and shall be included in the study. A brief description of
other major existing and proposed land developments within the study
area shall be provided.
B. Transportation facilities description.
(1)
Proposed internal transportation system. Describe
the proposed vehicular bicycle and pedestrian circulation, ingress
and egress locations, existing or proposed internal roadways including
the widths of cartways and rights-of-way, parking conditions, traffic
channelizations and any other traffic control devices within the site
of the subdivision or land development.
(2)
External transportation system. Describe the entire
external roadway system within the study area for the proposed subdivision
or land development including major intersections, traffic control
devices, parking conditions, widths of cartways and rights-of-way,
and vehicular, bicycle, and pedestrian circulation. Key intersections
in the study area shall be identified and described. Current photographs
of the study intersections depicting all approaches shall be included
in the study. All planned or programmed public and/or private highway
improvements, including proposed roadway construction and traffic
signalization, shall be noted. Any proposed roadway improvements planned
and approved from surrounding developments shall also be recorded.
C. Existing traffic conditions.
(1)
Existing traffic conditions shall be determined
for all roadways and intersections in the study area. Existing traffic
volumes for average daily traffic, peak highway hour(s) traffic, and
peak development-generated hour(s) traffic shall be collected. Manual
traffic counts at key intersections in the study area shall be conducted,
encompassing the peak highway and development generated hour(s). A
volume capacity analysis based upon existing volumes shall be performed
during the peak-highway hour(s) and the peak development-generated
hour(s) for all roadways and key intersections in the study area using
the methodologies presented in the current edition of the Transportation
Research Board's Highway Capacity Manual, current edition. Levels
of service shall be determined for all roadways and key intersections.
Traffic signal warrant analyses shall be conducted for all unsignalized
intersections in accordance with PennDOT Publication 212. Gap studies
and queue length analysis shall also be completed for all key intersections.
The analysis of the existing road network will be based on the current
geometric condition and traffic conditions.
D. Future trip projections.
(1)
Estimation of vehicular trips to result from the
proposed development shall be completed for the average daily, peak
highway hour(s) and peak development-generated hour(s). Vehicular
trip generation rates to be used for this calculation shall be based
on ITE's Trip General Manual, and ITE's Trip Generation
Handbook, current editions, and/or data collected from sites with
similar trip generation characteristics. This existing data shall
be collected in conformance with the guidelines presented in the ITE
Trip Generation Handbook. Also, provide an estimate of anticipated
truck volumes in the study. These development-generated traffic volumes
shall be provided for the inbound and outbound traffic movements and
the reference source(s) and methodology followed shall be documented.
All turning movements shall be calculated. These generated volumes
shall be logically distributed to the study area and assigned to the
existing roadways, and key intersections throughout the study area.
The methodology used to distribute trips shall be documented and approved
by the Township Engineer.
(2)
Provide a detailed distribution and assignment
of any pass-by trips. Document all assumptions used in the distribution
and assignment phase in a manner which permits the duplication of
these calculations. Pedestrian volumes shall also be calculated, if
applicable. If school crossings are to be used, pedestrian volumes
shall be assigned to each crossing. Any characteristics of the site
that will cause particular trip generation problems shall be noted.
(3)
Background growth using the latest edition of
the PennDOT Publication entitled "Pennsylvania Traffic Data" and projected
traffic from approved but not yet built subdivisions or land developments
which are proximate to and will have an impact on the study points
shall be included in the projection of future traffic.
(4)
All future analyses shall be conducted based upon
a full build out in the planned opening year plus a ten-year horizon
period. For phased projects, the entire project shall be assumed to
be built out in the opening year plus the aforementioned ten-year
horizon period.
E. Transportation impacts.
(1)
The study area roadway network is to be analyzed
for safety and capacity sufficiency for future network conditions
without the proposed development and future network conditions with
the proposed development. For each of these conditions, the following
analyses shall be completed:
(a)
Mainline ADT volumes and turning movement volumes
for all key intersections within the study area shall be determined
for the AM peak hours, PM peak hours and the proposed development
peak hours, if other than either the AM or PM peak hours of the network.
Commercial development shall also provide a Saturday peak hour analysis.
(b)
The effectiveness of the traffic signal control
at all key intersections shall be evaluated by approach in terms of
vehicle stops and delays.
(c)
Gap studies will be conducted at the proposed
site access points to evaluate the need for signal control, turn prohibition
or additional site access points to reduce the left volume from the
site driveway(s).
(d)
Queue length studies using 95% Highway Capacity
Manual methodologies shall be completed to evaluate the potential
for a backup of traffic from controlled intersections which could
impact other intersections including access points to the proposed
development.
(e)
An analysis of the volume and capacity of the
network and all key intersections shall be conducted utilizing the
most current Highway Capacity Manual procedures. Levels of service
will be determined and documented.
(2)
The analysis of the future conditions without
the proposed development will document the adequacy of the study area
network to accommodate the traffic in the design year(s) without the
proposed development. This analysis must include a full consideration
of all committed roadway improvements to the study area network when
determining the expected levels of service.
(3)
The analysis of the future conditions with the
proposed development will document the impacts created as a result
of the development.
F. Conclusions and recommended improvements. Levels of service
for all street segments and key intersections shall be presented in
tabular and graphic form. All street segments and key intersections
showing a level of service below D for street segments and signalized
intersections, and below E for street segments and unsignalized intersections
shall be considered deficient, and specific recommendations for the
elimination of these deficiencies shall be listed. This listing of
recommended improvements shall include, but not be limited to, the
following elements: internal circulation design, site access location
and design, external street and intersection design and improvements,
traffic signal installation and operation, and transit design improvements.
All newly signalized intersections shall be designed to provide a
level of service of D or better for all approaches for the horizon
year. All un-signalized intersections shall be designed to provide
a level of service of E or better for all approaches in the horizon
year. All physical on-site improvements shall be shown on the subdivision
and/or land development plan and approved by the Township Engineer
prior to any plan approval by the Board of Supervisors. Any future
phased improvements shall also be planned and represented by a phasing
schedule outlining the time frame or threshold for implementation
along with the responsible party. For each recommended off-site improvement,
provide a schematic drawing of existing and proposed conditions as
well as a narrative description of the improvement, including the
estimated cost of the improvements. All recommended improvements shall
be clearly feasible from an engineering and construction perspective.
Costs shall be separated for any recommended off-site improvements
and any required on-site improvements.
A final report shall be prepared to document the results of
the traffic study and the recommended improvements to accommodate
the projected traffic due to the proposed development. Provide an
executive summary which provides a concise description of the study
area, results of the traffic analyses, and any recommended improvements.
The presentation of data and analyses results should be accomplished
on either schematic diagram of the study area, or through the use
of charts and/or tables. All sources of data and methodologies which
were used in the study (including computer programs) must be properly
referenced and documented. Any waiver requests to the referenced procedures
must be properly documented to enable a review of the appropriateness
of the modification. Provide all computer output and calculations
in appendices.
Where the traffic impact study indicates that on-site improvements
are necessary or advisable to existing Township and/or state streets
and intersections in order (i) to assure adequate, safe and convenient
access to each lot and structure and parking compound proposed as
part of the development of the subject tract, (ii) to accommodate
the traffic due to the proposed development, (iii) to provide for
an acceptable 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 (iv) to preserve
the existing convenience of access to or ability to exit from abutting
lots which gain access from the existing street, the applicant shall
install all such indicated on-site improvements. The applicant shall
install additional traffic lanes, traffic dividers, traffic control
devices, traffic signals, and other measures as appropriate to ensure
that the development of the subject tract does not adversely impact
the existing street system and access to or the ability to exit from
lots gaining access from an affected street. If the traffic impact
study indicates that on-site improvements must be made to a state
roadway, the applicant shall also take all action necessary to obtain
any Pennsylvania Department of Transportation permits and approvals
to install the necessary street widening or traffic signals or traffic
control devices. If the traffic impact study recommends installation
of traffic signals or traffic signal modifications as part of the
on-site improvements, the applicant shall prepare all plans and 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. 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 as part of the on-site improvements,
the applicant shall prepare all traffic 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 applicant shall bear all costs and expenses in connection
with the on-site improvements required by this article. If the applicant
requires the Township to submit any permit applications or requests
for approvals in the name of the Township, the applicant shall reimburse
the Township for all costs and expenses incurred by the Township 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 Township determines that a portion or all of the
required on-site improvements or that a portion or all of any agreed
to off-site improvements are not feasible or appropriate at the present
time, the applicant shall enter into a applicant's Agreement
with the Township and deposit financial security with the Township
until such time that the improvements are satisfactorily installed
by the applicant and accepted by the Township in accordance with other
provisions of this chapter.