Transcript Slide 1

Secondary Street Acceptance Requirements
Nick Donohue
October 2008
Secondary Street Acceptance
Requirements
• Initiative is a result of legislation proposed by Governor
Kaine and unanimously approved during the 2007 General
Assembly Session
• Legislation requires the Commonwealth Transportation
Board to develop new Secondary Street Acceptance
Requirements
• Regulation will supersede and replace existing Subdivision
Street Requirements
• Intended to ensure streets accepted into state system for
perpetual public maintenance provide public benefit
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Why Update Secondary Street
Acceptance Requirements?
• Isolated developments cause additional strain on
the regional transportation network by forcing
local trips onto major roads
– Requiring all trips – local and regional – to rely on major
roads is not sustainable
• Increased connectivity will allow for context
sensitive design neighborhood streets
– Will help encourage friendly environments for
pedestrians and bicyclists, and discourage speeding in
neighborhoods
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Why Update Secondary Street
Acceptance Requirements?
Today
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Goal
Secondary Street Acceptance
Requirements
To be accepted into state system streets must provide
public benefit, defined as:
• Public service
• Connectivity*
• Pedestrian accommodations*
*Vary depending on location of development
Streets may be accepted as:
• Network addition (group of streets)
• Individual street
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Secondary Street Acceptance
Requirements
Network Additions
• Evaluating connectivity requires consideration of all
streets in a proposed development as a whole
instead of individually
• Streets within a development or a phase of a
development will be considered as a group for
acceptance into the state system
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Area Types
Proposed regulation:
• Establishing graduated requirements based on location and
conditions, with appropriate flexibility
• Creating areas based on long-term local, regional and
federal planning boundaries
• Three tiered system – one size does not fit all
– Compact Area Type
– Suburban Area Type
– Rural Area Type
• Area types may be modified at the request of the local
governing body
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Connectivity Requirement
The goal is to require additional connectivity
between developments
Connectivity is measured through a connectivity
index for compact and suburban area types
Connectivity index is the number of street segments
divided by the number of intersections and dead
ends
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Connectivity Requirement
Connectivity index increases as connectivity
of road network increases
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Connectivity Requirements - Examples
The highest connectivity index that can be achieved is over 2.5
The lowest connectivity index that can be achieved is 1.0
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Connectivity Requirements
Compact Area Type
•
Network addition must have sufficient connections to have a
connectivity index of 1.6 or greater
Suburban Area Type
•
Network addition must have sufficient connections to have a
connectivity index of 1.4 or greater
Rural Area Type
•
Network addition must have multiple connections
All Area Types
•
•
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Developments must connect with adjoining development’s stub-outs
to be eligible for acceptance into state system
Connections should be in multiple directions to both local and higher
order roadways
Connectivity Exceptions
Connectivity is not always feasible
Automatic reductions would be given
for perimeter constraints such as
wetlands, existing development,
rivers, terrain, railroad tracks, etc
In this example 25% of the perimeter
is effectively eliminated for
connections due to railroad tracks,
so the connectivity index is
automatically reduced from
1.4 to 1.3 or 25%
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Connectivity Exceptions
• Review related exceptions
– Incompatible land use
– Unique characteristics of parcel
– Access management regulations
• Consideration would be built into initial
conceptual sketch review
– VDOT would be required to respond within 45 calendar
days
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Grandfathering
• Streets within a proffered plan of development,
site plan/subdivision plat, preliminary subdivision
plat or approved street construction plan may be
accepted under former requirements
• Proposals officially accepted for review by a local
government may be accepted under the former
requirements at the request of the locality
• Regulation allows previous area type
requirements to apply when area type is modified
after approval of development proposal
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Pedestrian Accommodations
Based on density
• Accommodations on both sides of the street with two
or more units per acre
• Accommodations on one side of the street with lot
sizes of two acres or less
• Requirements for “missing link” connections
• Accommodations required along higher order
roadways
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Street Design
These local streets – with multiple
on-street and off-street parking
spaces for each house – have lane
widths effectively six feet wider
than most interstates
Lane widths of this size can
encourage travel at high speeds
and increase impervious surface
area
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Street Design
This design and lane widths are necessary in many situations
today due to emergency access needs and the lack of
connectivity
Increased vehicle speeds increase pedestrian injuries and
fatalities
Studies have also found a
correlation between local street
widths and accident rates
A Colorado locality found its
accident rates were significantly
higher on wider local streets
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Street Design
Connectivity allows design of local streets will result
in lower vehicle speeds – built-in traffic calming
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Street Design
Increased connectivity can allow the use of context sensitive street design which can:
•Promote safe environments for pedestrians, bicyclists and children
•Reduce stormwater runoff
•Discourage high travel speeds within neighborhoods
Recommended widths promote context sensitive solutions and are in compliance with
engineering principles including AASHTO and Institute of Traffic Engineers
Based on understanding that local roads serve access to property and disperse traffic
(curb and gutter)
Recommended
Standards
Current Standards
Less than 2000 vehicles
29 ft
36 ft
2001 to 4000 vehicles
36 ft
40 ft
* Widths assume on-street parking on both sides of the street
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Stormwater Runoff
VDOT has worked with DCR and private
sector to develop list of innovative
stormwater facilities that can be placed
within VDOT right of way
Today, stormwater
facilities are not
permitted within
VDOT right of way
Implementation
VDOT will produce a guidance document to accompany
regulation to assist local staff and developers
There will be a 6 month transition period from effective date
for the implementation of the regulation
VDOT will provide outreach and training similar to the
outreach and training that was provided for the Traffic
Impact Analysis regulations (Chapter 527)
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