The purpose of this article is as follows:
[Amended 10-2-2000 by Ord. No. 2000-11]
A transportation impact study shall be submitted
regarding subdivision and land developments which meet the following
criteria:
A.
Residential: involving 25 or more dwelling units.
B.
Nonresidential: involving 100 or more new peak-hour
trips.
C.
Preapplication meeting: The Township Engineer may
determine that a traffic study or narrative is needed to demonstrate
that the existing traffic generated from the site will not require
a modification of the existing transportation network.
D.
Other: whenever the Planning Commission or Board of
Supervisors shall find that there is a reasonable ground to believe
that the existing transportation network may be inadequate to handle
the volume or character of traffic likely to result from the proposed
subdivision or land development.
The study shall be prepared by a professional
engineer registered in the Commonwealth of Pennsylvania with sufficient
prior traffic study experience to qualify the engineer to perform
the study and render any opinions and recommendations set forth therein.
Study area boundaries shall be determined in accordance with the publication referenced in § 173-70 and through discussion with the Township Planning Commission and Township Engineer. A pre-study conference between the applicant's traffic engineer and the Township is encouraged.
The study shall be prepared in accordance with
the Institute of Transportation Engineers' Recommended Practice "Traffic
Access and Impact Studies for Site Development," current edition,
and PennDOT Publications 201 and 282, current edition, and the requirements
contained herein.
A.
General site description. 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. A brief description of other major existing and
proposed land developments with 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. All planned or
programmed public and/or private highway improvements, including proposed
roadway construction and traffic signalization, shall be noted. Any
proposed roadway improvements resulting from surrounding developments
shall also be recorded.
C.
Existing traffic conditions. 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 201. Gap studies
and queue length analysis shall also be completed for the key intersections.
The analysis of the existing road network will be based on the current
geometric conditions 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
Generation Manual, current edition, and/or data collected from sites
with similar trip generation characteristics. Also, an estimate of
anticipated truck volumes is to be provided. These development-generated
traffic volumes shall be provided for the in-bound and out-bound traffic
movements, and the reference source(s) and methodology followed shall
be documented. All turning movements shall be calculated. These generated
volumes shall be distributed to the study area and assigned to the
existing roadways and key intersections throughout the study area.
(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 and projected traffic from adjacent
land development shall be included in the projection of future traffic.
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 will be determined
for the a.m. peak hours, p.m. peak hour and the proposed development
peak hours, if other than either the a.m. or p.m. peak hours of the
network.
(b)
The effectiveness of the traffic signal control
at all key intersections will 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 prohibitions
or additional site access points to reduce the left-turn volume from
the site driveway(s).
(d)
Queue length studies will 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 will 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 roadway segments and key intersections shall be presented
in tabular and graphic form. All roadway segments and/or key intersections
showing a level of service below D for roadway segments, signalized
intersections 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 roadway and intersection
design and improvements, traffic signal installation and operation
and transit design improvements. All physical roadway improvements
shall be shown on the preliminary plan. Existing and/or future improvement
transportation service shall also be addressed. For each recommended
improvement, a schematic drawing of existing and proposed conditions,
as well as a narrative description of the improvement, including the
cost and funding method of the improvement and the implementation
schedule for the improvement, will be provided.
A final report must be prepared to document
the results of the traffic impact study and the recommended improvements
to accommodate the projected traffic due to the proposed development.
An executive summary which provides a concise description of the study
area, results of the traffic analyses and any recommended improvements
will be provided. The presentation of data and analyses results should
be accomplished on either schematic diagrams 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 modifications to the referenced
procedures must be properly documented to enable a review of the appropriateness
of the modification. All computer output and calculations in appendices
will be provided.
