Secondary Street Acceptance Requirements

Nick Donohue

October 2008

2

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

3

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

4

Why Update Secondary Street Acceptance Requirements?

Today Goal

5

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

6

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

7

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

8

9

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

10

Connectivity Requirement

Connectivity index increases as connectivity of road network increases

11

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

12

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• 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

13

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%

14

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

15

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

16

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

17

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

18

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

19

Street Design

Connectivity allows design of local streets will result in lower vehicle speeds – built-in traffic calming

20

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

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

22

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)