[Ord. No. 39-1998, § 5.1, 12-1-1998]
The City engineer may request the developer to submit a prepared
traffic and/or parking impact report for any proposed development
where the proposed development is calculated to generate an increase
of more than 35 new vehicle trips during the peak hour (times when
the highest traffic volumes are recorded, generally 7:00 to 9:00 a.m.
and 3:00 to 6:00 p.m.). This standard sets the threshold for determining
when a traffic/parking study is required. The traffic generation calculation
will be performed by the developer's engineer using data contained
in the 1982 edition (or current edition) of the Institute of Transportation
Engineers Trip Generation Handbook, which is on file in the City code
enforcement office. A parking assessment may be requested when the
proposed development can be expected to have a total parking demand
of 30 spaces or more as determined by values contained in the 1985
(or current edition) of the Institute of Transportation Engineers
handbook titled "Parking Generation," which is also on file in the
City code enforcement office. The developer will be required to retain
a state-registered professional engineer, specializing in traffic/transportation
engineering, to complete any necessary studies. All issues and questions
raised by the City will be adequately responded to as determined by
the City engineer. The planning board may request a traffic study
even if the increase is less than 35 new vehicle trips, if it is determined
by the City engineer that one is warranted.
[Ord. No. 39-1998, § 5.2, 12-1-1998]
(a)
Vehicular access to developments shall be from streets or roads that
have adequate capacity to accommodate the additional traffic generated
by the development. Level of service after development at intersections
on major access routes to the development and at the intersection
of any development access drive or proposed street shall be at a minimum
at pre-development levels of service. The developer shall mitigate
development impacts that result in a reduced level of service.
(b)
For development that will result in a reduction in level of service,
the level of service restriction may be lowered by the City engineer
after consultation with the state department of transportation, if
applicable, and upon written recommendation from the public safety
committee. At a minimum, recommendations shall be based upon adopted
goals and policies.
(c)
The City engineer may waive and/or modify any of the requirements
of this section if the developer's certified traffic engineer
can demonstrate that they are not necessary because of size, type,
or location of the development and/or because other traffic impact
analysis methods or procedures are equally effective.
[Ord. No. 39-1998, § 5.3, 12-1-1998]
The procedure for conducting a traffic impact analysis is as
follows:
(1)
Inventory existing and proposed land use.
a.
Existing land use. Site location and setting are important in determining
the potential impacts of development on a given site. The site description
shall include the following:
b.
Proposed land use. Adopted comprehensive plans, community development
plans, long range plans, or similar documents shall be reviewed when
inventorying proposed land uses. This will provide an indication of
the type and direction of future development that is generally acceptable
to the community and that may be facilitated by community facilities
such as streets, sewers, and water lines. Quantification of trip generation
shall also be developed.
(2)
Inventory existing and proposed transportation system.
a.
Existing transportation system. An understanding of the nature and
function of the existing and proposed transportation system in the
area near a proposed development site is essential for predicting
traffic patterns, performing the traffic analysis, and developing
necessary improvement alternatives. The following information shall
be provided:
1.
Current and proposed street network, including functional classification,
route jurisdiction, and the number of moving traffic lanes.
2.
Geometrics and characteristics, especially at critical intersections,
including such items as curb parking and potential street improvements.
3.
Intersection traffic control.
4.
Signal timing and system operation at signalized intersections.
5.
Existing or proposed intersection and development access points
and configurations.
6.
Existing and proposed rights-of-way.
7.
Available hourly traffic counts.
8.
Peak period turning movements at critical intersections.
9.
Accident information.
10.
Transit routes/headways.
11.
Transit stops/station locations.
(3)
Forecasted nonsite traffic volumes. Nonsite traffic consists of through
traffic volumes, having neither an origin nor a destination in the
vicinity of the development, and traffic generated by developments
adjacent to and affected by, or having an impact on, the proposed
development. Methods used to determine nonsite traffic volumes shall
include use of the following:
a.
Comprehensive transportation plan or related data projections; check
land use and socioeconomic information.
b.
Typical annual growth rates; provide sufficient historic volume information
and develop factors to apply to existing counts.
c.
Estimate development-generated units of measure and rates for components.
(4)
Site-related traffic.
a.
Divide activities associated with development into components.
b.
Identify trip generation units of measure and rates for components.
c.
Estimate development-generated units of measure and rates for components.
d.
Identify the critical hours of analysis such as the adjacent street
morning and evening peak hours and/or the proposed development peak
hour of activity.
e.
Trip distribution: The trips generated shall then be distributed
to the transportation system on the basis of land use, population
or employment, distance, accessibility, and any local factors affecting
distribution. The distribution should reflect conditions for the analysis
year, and the methodology should be well documented.
f.
Modal split: If the magnitude of the development is significant,
a determination of the mode of travel may be necessary. The determination
of trips generated is most likely in terms of vehicle trips; therefore,
an assessment of vehicle occupancy shall be performed to convert vehicle-trips
to person-trips. Then, the alternative modes of travel shall be analyzed
as to their attractiveness to development-generated traffic.
g.
Trip assignments: Trips for various transportation modes shall be
assigned to existing and proposed transportation networks based on
available system capacity, convenience, and other relevant criteria.
Traffic assignments shall reflect logical routing and realistic roadway
capacity potential.
(5)
Traffic analysis.
a.
Combine non-site and site-related traffic (i.e., the traffic volumes
for the various stages of the proposed development and the determined
analysis periods: morning, evening, and/or development peak hours,
estimated in previous steps, in order to obtain estimates of total
projected traffic volumes).
b.
Capacity analyses shall be conducted for all critical intersections
and access points during peak traffic periods. Critical intersections
usually fall into the following categories:
1.
All major intersections within a certain distance of the development
as agreed to by the City engineer.
2.
All affected intersections where development traffic would increase
the volume to a level that would warrant improvements.
3.
All affected intersections that operate or would, after development,
operate below design levels of service.
c.
The results of the capacity analyses shall be used to identify street
and road segments and intersections near the development that are
or will, after development, be deficient in capacity; and to identify
safety-related constraints.
(6)
Street/road and access improvements. The previous information is
then used to identify and evaluate improvements that can be made to
maintain acceptable levels of service and to help decision-makers
to determine whether the impact of the proposed development on the
surrounding area is acceptable. Level of service D shall be considered
appropriate for urban design unless otherwise indicated by the City
engineer. The 1988 growth management plan, section 3.3.3, defines
levels of service. The following elements shall be addressed as applicable:
[Ord. No. 39-1998, § 5.4, 12-1-1998]
(a)
Vehicle storage area; base requirements for driveways. Driveways
not subject to other standards shall have a vehicle storage area for
purposes of safely entering onto the street or lane, adjacent to the
shoulder of the road. This area shall be 20 feet in length for the
width of the drive, and have grades of not more than 6%, up or down,
from the edge of the shoulder. An existing structure whose proximity
to the right-of-way is such that it prohibits this relationship will
be exempt. Minimum base requirement for a driveway is 18 inches of
aggregate base course. Regular usage of a driveway, in a working operation,
by commercial trucks over 23,000 GVW requires 24 inches of gravel
base.
(b)
Curb openings in residential districts. No permit for a permanent street curb opening in a residential district shall be issued for a use which is not listed as a permitted use or permitted use requiring planning board review in that district. Residential districts are outlined in chapter 102.
(c)
Authority of City engineer. The City engineer is authorized and directed
to determine locations and widths for driveways in the City in accordance
with the standards specified in this section.
(d)
Surfacing. All new surface for curb cuts or driveway openings within
the right-of-way will be bituminous hot top, and such work shall extend
to the rear of the sidewalk line only. All costs for such cuts shall
be borne by the property owner, and, if the City does the work, the
work will be paid for in advance on a per-foot basis as approved by
public works director.
(f)
Single- and two-family driveways (up to four parking spaces).
(1)
Width. Any site shall have a minimum twelve-foot driveway. Where
multifamily dwellings are proposed, a minimum twenty-foot driveway
shall be required.
(2)
Location. Wherever possible, driveways shall be located on the
lot in a manner to provide a minimum twenty-foot spacing between existing
or proposed driveways.
(g)
Commercial, industrial and multifamily driveways (three units or
more).
(1)
Width of one-way driveways. Any site with driveway access to
a street shall have a minimum fifteen-foot-wide driveway for one-way
ingress or egress. Driveways shall permit traffic to enter and leave
the site simultaneously without conflict in aisles, parking or maneuvering
areas. Both the entrance and exit drives shall be marked with appropriate
signage. Maximum driveway width shall not exceed 24 feet.
(2)
Width of two-way driveways. Any site with driveway access to
a street shall have a minimum twenty-four-foot wide and maximum thirty-five-foot
wide driveway for two-way ingress and egress.
(3)
Curbing.
a.
Where driveways enter on an existing street, the full radius
of the driveway shall be curbed if necessary.
b.
The radius shall be a minimum of 15 feet. Where truck traffic
is anticipated, the radius may be increased up to a maximum of 25
feet based on the turning radius of the vehicles anticipated to enter
and exit the site.
c.
If curb cuts or culverts are required, they will be as approved
by the City engineer, and installed by public works department at
the developer's cost.
(4)
Maneuvering area. The area within the site to which a driveway
provides access shall be of sufficient size to allow all necessary
functions for loading, unloading and parking maneuvers to be carried
out on the site and completely off the street right-of-way.
(5)
Location and spacing. The location and spacing of driveways
shall be determined as follows:
a.
Along local streets, access driveways to corner lots shall be
located a minimum of 35 feet from the intersection of the projection
of the right-of-way line to the centerline of the driveway, except
as otherwise provided in this section.
b.
Along arterial, collector and industrial streets, access driveways
to corner lots shall be located a minimum of 150 feet from the intersection
of the projection of the right-of-way line to the centerline of the
driveway, except as otherwise provided in this section.
c.
Along arterial, collector and industrial streets, minimum acceptable
spacing between double or multiple driveways shall meet the following
criteria:
|
Speed Limit
(mph)
|
Minimum Separation
(feet)
| |
|---|---|---|
|
30
|
125
| |
|
35
|
150
| |
|
40
|
185
| |
|
45
|
230
|
|
Distances between adjacent one-way driveways with the ingress
drive separated from the egress drive may be 1/2 the distance shown
in this subsection.
|
d.
Driveways shall be located in the most appropriate location,
based on the existing and proposed adjacent and opposing driveways
and land use.
(6)
Number of driveways.
(7)
Off-street vehicular circulation. An off-street facility shall
have full internal vehicular circulation and storage. Vehicle circulation
shall be completely contained within the facility, and vehicles located
within one portion of the facility shall have access to all other
portions without using the adjacent street system.
(8)
Off-street truck maneuvering. Where the use of a parcel includes
truck loading, parking or service facilities, adequate space shall
be provided such that all truck maneuvering is performed off the street.
The design truck shall be one most appropriate for the operation.
(h)
Ingress lanes (slip lanes).
(1)
Ingress left-turn lane. A twelve-foot-wide left-turn lane with
appropriate storage and transition, based on the Institute of Traffic
Engineers accepted standards, shall be provided at each driveway where
the peak hour inbound left-turn volume is 30 vehicles or more.
(2)
Ingress right-turn lanes. For any site, a twelve-foot-wide right-turn
lane with appropriate storage and transition, based on the Institute
of Traffic Engineers accepted standards, shall be provided at each
driveway where the highway average daily traffic exceeds 10,000 vehicles
per day, permitted highway speeds exceed 35 miles per hour, and driveway
volume exceeds 1,000 vehicles per day with at least 40 right-turn
movements during peak periods. For any site, a right-turn lane as
described in this subsection shall be provided at each driveway where
right-turn ingress volumes exceed 75 vehicles per peak hour.
(i)
Maximum length of driveway.
(1)
The maximum length of a driveway within the area zoned for shore
land protection shall be 500 feet.
(2)
A driveway may have any length, as it could access a parking
lot or a single-unit residence at a distance from the street. Any
one-lane driveway over 500 feet in length must provide a fifty-foot
by ten-foot passing lane at five-hundred-foot intervals for the purpose
of passing emergency vehicles running in the opposite direction to
traffic.
(j)
Driveways with steep slopes. For any driveway with any slopes steeper
than 12%, the applicant must provide a statement or plan that addresses
maintenance (especially winter maintenance), erosion, and drainage.
Should there be a question of safety (emergency vehicles, access use,
etc.), then the approval of the City public safety director is required.
[Ord. No. 39-1998, § 5.5, 12-1-1998]
Where driveways or roadways are proposed to enter onto an existing
street, vehicular sight distance shall conform to the recommended
sight distance listed in this section, and shall not be less than
the minimum sight distance standard. The minimum sight distance standards
are taken from table 5-4, page 127 of the Institute of Transportation
Engineers Handbook, current edition, titled Transportation and Land
Development, which is on file in the City services engineering bureau.
Vehicular sight distance shall be calculated with the height of eye
at 3.5 feet and the height of an object at 3.5 feet.
|
Posted Speed Limit
|
Recommended Sight Distance
(feet)
|
Minimum Sight Distance
(feet)
|
|---|---|---|
|
25 mph
|
250
|
150
|
|
30 mph
|
300
|
200
|
|
35 mph
|
350
|
250
|
|
40 mph
|
400
|
325
|
|
45 mph
|
450
|
400
|
|
50 mph
|
500
|
475
|
[Ord. No. 39-1998, § 5.7, 12-1-1998; Ord. of 1-5-2010(1)]
[Ord. No. 39-1998, § 5.8, 12-1-1998; Ord. of 1-5-2010(1)]
Where off-street parking is required or provided, the following
standards shall apply:
(1)
Driveways shall be designed in accordance with the traffic standards for driveways; see section 98-154.
(2)
When surfacing permanent lots, there shall be a minimum 12 inches
of gravel base below the pavement. If heavy vehicles (GVW 23,000 pounds
or greater) routinely use the parking lot after final construction,
the depth of base shall be 24 inches, or as determined by proper engineering
analysis and subject to approval by the City engineer. For all parking
lots:
(3)
A storm drain system is required such that stormwater shall not cross
any public sidewalk or street. The parking lot shall be graded so
that there is no standing water.
(4)
When parking lots abut the street, a continuous curb guard or wheel
stop, at least six inches in height and permanently anchored, shall
be provided and maintained for a width of at least three feet along
that part of the lot line abutting the street. Alternatively, a continuous
bumper guard of adequate strength, at least 20 inches in height, shall
be provided and maintained, so that bumpers of vehicles cannot project
beyond its face towards the street or lot line involved.
(5)
The surface of parking lots and parking areas must be paved, except
parking areas that are used exclusively for a single-family or two-family
residence.
Notwithstanding this requirement, the Planning Board has the
authority to waive this requirement and to allow the use of a crushed
stone surface for any parking lot or parking area that satisfies one
or more of the following criteria:
a.
A parking lot that serves 10 or less vehicles;
b.
A parking lot which serves a use that experiences a low turnover
in parking demand;
c.
A parking lot that serves a periodic or occasional type of use, such
as but not limited to a church;
d.
A parking lot that mostly serves as an overflow parking area;
e.
A parking lot located in a predominately rural area, or which is
located on a property which fronts on an unpaved road; or
f.
Circumstances similar to the above which the Planning Board finds
appropriate.
[Ord. No. 39-1998, § 5.9, 12-1-1998]
Each loading bay shall have minimum dimensions of 50 feet by
14 feet and be located either within a building or outside and adjoining
an opening in the building, except that, in the case of hospitals,
nursing homes and convalescent homes, the off-street loading area
provided for ambulances and other emergency vehicles shall be exempt
from the minimum dimension requirement but shall be of sufficient
width and depth to permit safe and convenient access and egress from
the loading area. Every part of such loading bay shall be located
completely off the street. In any case where trucks, trailers, or
other motor vehicles larger than the dimensions of the minimum loading
bay habitually serve the building in question, additional space shall
be provided so that each vehicle shall park or stand completely off
the street.
