Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users

On 10 August 2005, the new Federal surface transportation act (SAFETEA-LU) was signed into law, authorizing a $286.4 billion transportation program for a 5-year period; FFY 2004-2009. This act covers all surface transportation programs, such as highways, highway safety, transit, freight, and transportation research.

Safe Routes To School

Mandated by federal law (SAFETEA-LU), “Safe Routes To School” is intended to benefit children in primary and middle schools (K-8) by encouraging them to walk and bike to school regularly, routinely, and safely. SR2S integrates elements of transportation, economics, health, physical activity, environmental awareness and safety.

Satellite Facility

Otherwise known as an “Intercept Facility”, a Satellite “Park & Ride” facility’s purpose is to provide a less expensive parking alternative to on-site locations within activity centers or the urban core area and reduce SOV use in activity centers. These facilities may capture outgoing as well as incoming activity center traffic and serve as a transfer point from car to shuttle or transit. Characteristics include an urban/activity area fringe location, high capacity, surface or structured parking, and high frequency shuttle/transit connections to activity centers. Implementation funding is likely to come from Congressional earmarks and/or public private ventures.


The size and proportion of a Building, Structure, or Land Development in comparison with nearby development.

Scenario Planning

A framework and participatory excercise for developing a shared vision for the future by analyzing various forces (e.g. health, transportation, economic, environmental, land use, etc.) which affect a region’s growth. Scenario planning is a collaborative process that tests various future alternatives ability to meet regional and community needs.

Scenic Easement

A Conservation Easement used to limit development on a property in order to protect views of the property itself or to protect views of distant scenery.

Scenic Resources

Visually pleasing landscapes (such as mountains, farms, ridge lines and shorelines) and the locations providing vistas of those landscapes.


A phase in the project development process that moves a recognized problem from an idea through the development of alternatives and environmental screening (also See “Project Development Process”).


A fence, berm, or vegetation, often of a specified height, that visually obscures one area from another.

Secondary Impact

An indirect consequence of an action.

Section 248

The Vermont Law (30 VSA 248) governing how the Public Service Board may approve a proposed utility facility.

Septic System

A tank and a leaching field in which sewage is purified by bacterial action.

Service Center

A term used by this Plan to describe a Community Facility to which people go to obtain a particular public service (such as a community center) or that serves as the base of operations from which a particular public service is provided (such as a fire station).


The required distance that a building, structure, or land use must be from a lot line.


This term is used to denote the imposition of a mandate or duty.

Shared Use Path

A path separated from vehicle traffic by barrier or open space usually on its own right-of-way.


Otherwise known as a “Shared-Lane Arrow”, sharrows are employed on roadways too narrow for striped bicycle lanes and help to provide guidance to bicyclists and warn motorists about the presence of bicyclists. The sharrow is a printed image of a bike symbol underneath two chevrons upon the roadway.


10 VSA 1422 (8): Land between the normal mean water mark of a lake, pond or impoundment exceeding 20 acres and a line not less than 500 feet nor more than 1,000 feet from such mean water mark. See 24 VSA 4424.

Short Ton

A measure of weight equalling 2,000 lbs. The Short Ton is distinguished from the Long Ton (or British Ton), which equals 2,240 lbs., as well as the Metric Ton, which equals 2,204.62 lbs.

Should – 24 VSA 4303 (26)

This term is used to denote that an activity is enouraged but not man-dated.

Signal Optimization Analysis

This analysis maximizes roadway mobility and capacity (without undertaking expensive and inconvenient roadway widening projects) and can help to reduce pollution. More specifically, “Signal Optimization” is the efficient use of a municipality’s or corridor’s traffic signals by improving their timing parameters (Fixed-Cycle, Offset, and Split parameters) within the controller box located at an intersection to lessen acceleration and idle time of vehicles.

Signal Warrant Analysis

As defined by the Manual on Uniform Traffic Control Devices (MUTCD), a Traffic Signal Warrant Analysis is an engineering study of traffic conditions, pedestrian characteristics, and physical characteristics of the location shall be performed to determine whether installation of a traffic control signal is justified at a particular location.

Single Occupancy Vehicle

Vehicle carrying only a driver.

Site Plan

A Plat that depicts the general layout of a proposed Land Development.

Site Plan Review

The process by which a government reviews the Site Plan for a proposed development to ensure that the development will conform to applicable regulations. See 24 VSA 4416.

Sketch Plat (Plan)

A plat (typically prepared according to less formal standards than a Preliminary Plat or Final Plat) that depicts the general features and characteristics of a proposed subdivision and is submitted so that the Appropriate Municipal Panel may (1) provide informal comments in order to improve the likelihood that a subsequent preliminary plat or final plat will be acceptable and (2) classify the proposed subdivision as a Major Subdivision or Minor Subdivision.

Small Transit Intensive Cities

Federal program (or formula) intended to support public transportation in smaller urban areas that have transit systems that perform as well or better than systems in larger metropolitan areas (according to six performance categories; 1. Passenger miles traveled per vehicle revenue mile, 2. Passenger miles traveled per vehicle revenue hour 3. Vehicle revenue miles per capita, 4. Vehicle revenue hours per capita, 5. Passenger miles traveled per capita, and 6.Unlinked passenger trips per capita). Only MPOs with urban-area populations of less than 200,000 are eligible for this funding.

Smart Corridor

An area that uses advanced technology to maintain the flow of multimodal traffic at maximum efficiency.

Smart Growth

Programs and policies designed to maximize preservation of undeveloped land, natural, and cultural resources, whilst economically evolving the established developed communities. Vermont Statues (24 VSA 2791 (13)) describe Smart Growth as; Growth that: (A) Maintains the historic development pattern of compact village and urban centers separated by rural countryside. (B) Develops compact mixed-use centers at a scale appropriate for the community and the region. (C) Enables choice in modes of transportation. (D) Protects the state’s important environmental, natural and historic features, including natural areas, water quality, scenic resources, and historic sites and districts. (E) Serves to strengthen agricultural and forest industries and minimizes conflicts of development with these industries. (F) Balances growth with the availability of economic and efficient public utilities and services. (G) Supports a diversity of viable businesses in downtowns and villages. (H) Provides for housing that meets the needs of a diversity of social and income groups in each community. (I) Reflects a settlement pattern that, at full build-out, is not characterized by: (i) scattered development located outside of compact urban and village centers that is excessively land consumptive; (ii) development that limits transportation options, especially for pedestrians; (iii) the fragmentation of farm and forest land; (iv) development that is not serviced by municipal infrastructure or that requires the extension of municipal infrastructure across undeveloped lands in a manner that would extend service to lands located outside compact village and urban centers; (v) linear development along well-traveled roads and highways that lacks depth, as measured from the highway.

Soil Conservation Service

Soil Conservation Service

Solar Access

The ability to receive direct sunlight between specific times of the day.

Solid Waste

10 VSA 6602 (2): Any discarded garbage, refuse, septage, sludge from a waste treatment plant, water supply plant, or pollution control facility and other discarded material including solid, liquid, semi-solid, or contained gaseous materials resulting from industrial, commercial, mining, or agricultural operations and from community activities (but does not include animal manure and absorbent bedding used for soil enrichment or solid or dissolved materials in industrial discharges which are point sources subject to permits under the Water Pollution Control Act (10 VSA Chapter 47)).


The distance a bridge extends between two supports, or a single piece of support frame, which spans the length of the bridge structure.

Special Needs Population

Those persons requiring specific housing modifications or arrangements including people with physical or mental disabilities, the homeless, those adjusting to society after being incarcerated, and sometimes the elderly.

Special Plan

A plan that describes, analyzes, and makes Policies about one or more specific topics (such as community facilities, economy, housing, land use, population, and transportation) or for a designated sub-area (such as a Corridor). A Special Plan may or may not be officially adopted as an amendment of a Comprehensive Plan. See 24 VSA 4403 (5) (municipalities) and 24 VSA 4345(6), (11), and (13) (RPCs).

Special Service District

A contiguous, designated area that receives a special type and/ or level of one or more public services or infra-structure that is paid for by a special tax levy on properties located in the area.

Special Services Transportation Agency

Chittenden County non-profit organization providing paratransit services.

Special Trip Generators

In modeling context, special generators represent employers (or employer locations) with unique characteristics that are especially large and therefore need to be handled outside of the normal trip generation approach. Examples for the Chittenden County, VT model include; IBM (Essex and Williston), the University of Vermont, and Fletcher Allen Health Care.

Speed Bumps

A Speed Bump is also a raised pavement area across a roadway. Speed bumps are typically found on private roadways and parking lots and do not tend to exhibit consistent design parameters from one installation to another. Speed bumps generally have a height of 3 to 6 inches (76 to 152 mm) with a travel length of 1 to 3 feet (0.3 to 1 m). From an operational standpoint, speed bump impacts within typical residential operational speed ranges slow vehicles to about 5 mph or less at each bump. Speed bumps of varying design have been routinely installed on private roadways and parking lots without the benefit of proper engineering study regarding their design and placement.

Speed Humps

A Speed Hump is a raised area in the roadway pavement surface extending transversely across the travel way. Speed humps are sometimes referred to as “pavement undulations” or “sleeping policemen”. Most agencies implement speed humps with a height of 3 to 3.5 inches (76 to 90 mm) and a travel length of 12 to 14 feet (3.7 to 4.3 m). Speed humps are generally used on residential local streets. From an operational standpoint, speed humps impact within typical residential operational speed ranges, slow vehicles to about 20 mph (32 km/h) on streets with properly spaced speed humps. Speed humps have evolved from extensive research and testing and have been designed to achieve a specific result on vehicle operations without imposing unreasonable or unacceptable safety risks.

Speed Tables

Speed Tables are essentially flat-topped speed humps, and may have a textured material on the flat section with asphalt or concrete for the approaches. Speed tables are sometimes referred to as “trapezoidal humps” or “speed platforms”. If marked as a pedestrian crossing, speed tables may also be referred to as “raised crosswalks” or “raised crossings”. Most agencies implement speed tables with a height of 3 to 3.5 inches (76 to 90 mm) and a travel length of 22 feet (6.7 m). Speed tables generally consist of 10 foot (3.1 m) plateau with 6 foot (1.8 m) approaches on either side that can be straight, parabolic or sinusoidal in profile. The longer lengths of speed tables provide a gentler ride than speed humps and generally result in vehicle operating speeds ranging from 25 to 30 mph (40 to 48 km/h) on streets depending on the spacing between speed tables. Speed tables are generally used on residential collectors, emergency routes or transit routes.

Spillover Effect (Externality)

A consequence of an action that is unintended or not of primary concern to the action takers.

Splitter Islands

A dual-purpose component of a roundabout that serves to deflect traffic speed of entering and exiting vehicles, as well as provide a temporary refuge to pedestrians where crossing is permitted along roadway approaches.

Spot Zoning

A change in Zoning that usually applies to a relatively small number of properties. A more specific meaning is a zoning change that is unlawful because it is intended to benefit a particular property owner (not the public welfare).


See; “Urban/Sub-Urban Sprawl”

Standard Land Use Coding Manual

Developed by the Housing and Urban Development Agency in 1965, SLUCM was a predecessor to the more current LBCS (APA’s Land-Based Classification Standards). The 1965 SLUCM provided a numeric coding schema using two, three, four, or more digits identifying land-use categories. An additional two to eight digits identified Ownership, Type of Structure an activity was housed, and Secondary Use Codes identifying additional land uses. SLUCM land uses categories were derived from Standard Industrial Classification (SIC) codes.

State Comprehensive Outdoor Recreation Plan

A comprehensive plan for outdoor recreation in each state is a requirement for receiving support from the Land and Water Conservation Fund (LWCF).

State Implementation Plan

Clean Air Act plan which identifies how the state will attain and/or maintain NAAQS standards.

State Planning and Research Funds

Funds intended for planning and research purposes. SPR funding requires that States allocate 2 percent of their apportionments received from federal programs (e.g. Interstate Maintenance, NHS, Surface Transportation, Highway Bridge, CMAQ, et al.) for State planning and research activities. From this 2 percent, States must then allocate 25 percent for research, development, and technology (RD&T).


A planning and management approach to land and natural resources that considers long-term sustainability, environmental impacts, and public benefits of actions as well as public and private dollar costs.

Stopping Sight Distance

The minimum distance a driver can see ahead in tandem with how long it takes for her/him to stop. According to the AASHTO “Green Book”, this distance is comprised of two components; 1. Perception-Reaction Time, which covers the distance a vehicle travels from the moment the driver sees an object necessitating a stop, to the instant the brakes are applied, and — 2. Braking Distance, which is the distance a vehicle travels during the braking maneuver.

Stormwater Detention (Retention)

Natural and man-made measures designed to slow or pre-vent the release of stormwater from a site so it may be released at a controlled rate or percolate into the ground to reduce the risk of flooding and to improve water quality.

Stormwater Runoff

10 VSA 1264 (14): Precipitation and snowmelt that does not infiltrate into the soil, including material dissolved or suspended in it, but does not include discharges from undisturbed natural terrain or wastes from combined sewer overflows.

Strategic Highway Network

A network of highways which are important for U.S. strategic defense policy and which provide defense access, continuity and emergency capabilities for defense purposes.

Strategic Highway Safety Plan

Required by federal law (SAFETEA-LU, 2005), An SHSP identifies a State’s key safety needs, whilst guiding investment decisions to achieve significant reductions in highway fatalities and injuries on all public roads. The SHSP facilitates all State highway safety programs to work in concert to align all its resources to collectively address safety challenges on all its public roads.


A public or private Right-of-Way intended primarily for vehicular use, typically required to be built to specific standards (See Arterial Street, Collector Street, Local Street, Alley, and Driveway).

Street Line

The boundary line of a Street that may extend beyond the paved portion of the street (See Right-of-Way Line).


24 VSA 4303 (27) ~ An assembly of materials for occupancy or use, including a building, mobile home or trailer, sign, wall, or fence.

Sub-base (of Road)

The load bearing and distribution layer of a road underneath the pavement and capping layer. The sub-base is often made of an aggregate such as gravel or crushed-concrete, which is spread and compacted in-place during construction. A Sub-base might also be made of a bound concrete slab in the case of a weak subgrade, or when heavy loads are expected upon the roadway.

Subdivision Regulation

A municipal bylaw that may (1) regulate the procedures and requirements for the submission and processing of plats, and (2) establish standards for the design and layout of streets, curbs, gutters, street lights, fire hydrants, shade trees, water sewage and drainage facilities, public utilities and other necessary public improvements. See 24 VSA 4418 and 4463.


The division or re-division of a lot, tract, or parcel of land into two or more lots for the purpose (whether immediate or future) of lease, transfer of ownership, development, or improvement. For the purposes of Act 250, subdivision is defined by 10 VSA 6001 (19).

Subgrade (of Road)

Classically known as the “Formation Level”, the subgrade of a road is the underlying layer beneath the sub-base. The subgrade is at the lowest level of excavation for a road structure and is leveled off to serve as the foundation. A good subgrade should be at least compacted soil that has a low-permeability.

Substantial Regional Impact

In the context of the State of Vermont planning practice, a proposed development has a Substantial Regional Impact (SRI) if a policy of this Regional Plan that is relevant to the determination of an issue in an Act 250 or Section 248 proceeding makes recommendations that are more specific about one or more characteristics, features, standards, or conditions relating to the proposed development than the recommendations of the municipal plan. SRI is an impact of Land Development that triggers the requirements of 24 VSA 4345a (16), (17), and 4348 (h). An SRI is not automatically in conflict with a regional plan. An SRI is not always an Adverse Impact. 24 VSA 4345a (17) requires each RPC to define SRI as the term is to be used with respect to its region in its Regional Plan. This Regional Plan discusses and defines SRI for Chittenden County at pages 1-14 to 1-18.

Substantive Due Process

This form of the constitutional right of Due Process requires that a government’s laws or actions that take or deny a person’s life, liberty, or property must (1) be based on one or more legitimate governmental purposes, (2) employ means to achieve those purposes that are related to achieving that purpose, and (3) employ means that are reasonable. See Taking.


Within context of the architecture of the National Intelligent Transportation Systems (ITS) Architecture, subsystems are individual pieces of the ITS. Subsystems are grouped into four classes: Centers, Field, Vehicles, and Travelers. Example subsystems are the Traffic Management Subsystem, the Vehicle Subsystem, and the Roadway Subsystem. These correspond to the physical world: respectively traffic operations centers, automobiles, and roadside signal controllers. Due to this close correspondence between the physical world and the subsystems, the subsystem interfaces are prime candidates for standardization.

Sufficiency Rating

A measure of road or bridge adequacy. A section of road that is completely adequate in every respect is rated at 100. Any deficiency in the road that affects the structural condition, efficient movement of traffic, or safety reduces the rating as far down as zero.

Sulfur Dioxide

Petroleum fuels contain traces of sulphur compounds and produce Sulfur Dioxide (SO2) during combustion. The majority of the SO2 pollution comes from power generation, which is a significant cause of “Acid Rain”. Except for the shipping mode, transportion is not a major contributing source of SO2.

Super Ultra Low Emission Vehicle

A vehicle producing 90 percent less pollutants than an average gasoline-powered vehicle for the year of manufacture.

Supply Chain Consortium

A private-sector consortium which collects data, develops indicators, advises on “Best Practices” optimizing performance and profitability of a supply chain.

Supply Chain Management

Planning and management of business activities involved in movement of freight. SCM seeks to equalize supply and demand across all tiers of the chain (e.g. Supplier — Primary Manufacturer — Secondary Manufacturer — Regional Warehouse — Distributor — Retailer — Consumer).

Surface Transportation Program

Federal program providing flexible funding for projects on any Federal-aid highway, including the NHS, bridge projects on any public road, transit capital projects, and bus facilities.

Surface Waterbodies

Water bodies where water collects on or flows across the earth’s surface (such as ponds, lakes, reservoirs, rivers, and streams). See Ground Water, Watershed, and Wetland.

Swept Path Width

Amount of roadway covered in negotiating a turn; equals the “offtracking” width (i.e. The difference between the front and rear wheelpaths when a bus or truck is negotiating a turn) plus the tractor unit or bus width.