CMAQ | AQ Maps | AQ Resources | Commute Options
1-87 Ridefind:
1-87 Ridefind Site
A statewide rideshare database managed by the Atlanta Regional Commission under contract with the Georgia DOT. Primarily covers the greater Atlanta Region but is expanding.
Alternative Fuel Vehicles (AFV):
Motorized vehicles that utilize a non-gasoline based fuel. The most common types are electric, natural gas (CNG), and propane. Newer hybrid vehicles do not qualify yet, despite their super efficiency, because they use gasoline as a fuel.
Alternative Work Arrangements:
The use of work design that results in reductions in commute trips, or in spreading the rush hour over a longer time frame. Telecommuting, job sharing, staggered work shifts, compressed work weeks, on-site daycare, and flex-time are common strategies.
Bicycle Lane:
GDOT's Bicycle and Pedestrian Site
A section of a road striped and marked for the exclusive use of bicycles. Must be at least four feet wide to be legally marked as such.
Capacity:
The rate of vehicular or person flow that can be expected to cross a point on a sidewalk, lane or roadway during a specific period.
Carbon Monoxide (CO):
A colorless, tasteless gas that in most cases is produced by the combustion of organic fuels in transportation and industrial-related activities. Considered a mobile source pollutant.
Clean Air Amendments of 1990 (CAAA):
Federal legislation that establishes acceptable levels of certain criteria pollutants.
Clean Air Campaign (CAC):
Serves as a clearinghouse for a multitude of organizations that have programs in place to address traffic congestion and air pollution. Collectively they work with more than 600 employers in the region to mitigate traffic congestion and improve air quality. CAC is unique to the Atlanta region by also providing TDM products and services in areas not serviced by a Transportation Management Association. The CAC also has responsibility for regional advertising and public relations for TDM issues.
Congestion Mitigation and Air Quality Improvement Act (CMAQ):
GDOT CMAQ site
A source of funding for Transportation Demand Management activities, which seek to reduce auto-dependency and encourage the use of options like transit, ridesharing, bicycling, and alternative work arrangements.
Cold Start:
An internal combustion engine generates much higher levels of pollution in the first 5 minutes of a trip, before the engine has warmed and the catalytic converter can work. Avoiding cold starts by linking many trips together can significantly reduce pollution.
Conformity:
A process in which transportation plans and spending programs are reviewed to ensure that they are consistent with federal clean air requirements and the State Implementation Plan (SIP); regional transportation projects collectively must not worsen air quality.
Corridor:
In planning, a broad geographical area of land that follows a general direction/flow or connects major sources of trips. It may contain a number of streets, highways, transit lines and routes. It generally follows a transit line, interstate, freeway or major roadway.
Commuter Rail:
GDOT's Passenger Rail Site
Generally speaking, this mode of transportation utilizes a multi-car system along an existing rail corridor (mainly, freight lines). Commuter Rail usually connects cities and does not have a large amount of stops. Commuter rail runs on or next to existing freight lines. The trains typically reach speeds of 80-90 MPH and can also connect suburban metropolitan areas to an urban core.
Compressed Workweek (CWW):
This means that employees work fewer but longer days, such as four 10-hour days each week (4/40), or 9-hour days with one day off every two weeks (9/80).
Congestion Pricing:
Road pricing that varies with the level of traffic on a congested roadway. Congestion pricing is intended to allocate roadway space efficiently by utilizing a user fee system where the roads cost more during high traffic volume periods.
Diesel Retrofit:
Emission control device(s) with very low levels of sulfur, resulting in a small reduction in particulate matter. These devices work because there is no sulfur in the fuel to poison the catalysts or plug the particulate trap.
Facility:
The means by which a transportation mode is provided. For example, sidewalks, freeways, bicycle lanes, and light rail are all facilities.
Fixed Guideway:
A transit route that is fixed in position, usually by rails, but sometimes by dedicated right of way, restricted access HOV, other technology. An example would be a road to be used only by a trolley or a bus or a rail lane for heavy trail.
Flextime:
This means that employees are allowed some flexibility in their daily work schedules. For example, rather than all employees working 8:00 to 4:30, some might work 7:30 to 4:00, and others 9:00 to 5:30. Generally, employees are allowed to choose their shift, within limits.
Fugitive dust:
Largely wind blown dust from paved and unpaved roads
Greenhouse Gas:
An emission that contributes to the collection of gases in the upper atmosphere that are widely considered by most scientists to be causing the gradual warming of the Earth. Included in these gases are carbon dioxide and natural methane gas. Also known as global warming.
Guaranteed Ride Home (GRH):
Programs provide an occasional subsidized ride to commuters who use alternative modes. For example, if a bus rider must return home in an emergency, or a carpooler must stay at work later than expected. This addresses a common objection to the use of alternative modes. GRH programs may use taxies, company vehicles, or rental cars.
Heavy Rail:
Heavy Rail is the typical subway-like cars MARTA uses in its rail network.
High Occupancy Vehicle Lanes (HOV):
GDOT HOV Site
Lanes dedicated for exclusive use by multi-occupant vehicles such as carpools, buses, and vanpools. In Atlanta, there are over 90 miles of HOV lanes on I-85, I-75, and I-20 east, and currently, motorcycles and alternative fuel vehicles are allowed to use the system.
High Occupancy Toll Lanes (HOT):
State Road and Tollway Authority Site
HOV facilities that allow lower occupancy vehicles, such as solo drivers, to use the facility if they pay a toll. This offers users three options: drive alone on an unpriced but congested general purpose lane, drive alone and pay to use a less congested lane, or rideshare (carpool, vanpool or ride transit) to use a less congested lane without any additional fee.
Hybrid:
Vehicles that use a combination of gasoline and electricity for motive power and thereby increase efficiency and reduce emissions.
Hydro Carbon (HC):
See Volatile Organic Compound
Inspection and Maintenance (I&M):
Refers to legislated requirements for vehicle inspection and maintenance for air quality assurance. Georgia's I&M program was implemented by the Georgia Environmental Protection Division (EPD) in 2000. GA EPD also monitors the Inspection program statewide.
Intermodal Surface Transportation Efficiency Act (ISTEA):
Landmark federal legislation signed into law in 1991. It made broad changes in the way transportation decisions are made by emphasizing diversity and balance of modes as well as the preservation of existing systems and construction of new facilities. The law expired in 1997, but much of the program were carried forward by TEA-21.
Intermodal:
Interconnectivity between various types (modes) of transportation.
Level of Service (LOS):
A qualitative measure describing operational conditions within a traffic stream and motorists' perceptions of those conditions. For example, LOS A is free flow, B: stable flow, C: stable flow but beginnings of congestion, D: high density but stable flow, E: at capacity level, and F: stop and go.
Light Rail:
Light Rail cars are comparable to the traditional trolley cars used in San Francisco, Portland, or on the Green Line in Boston. Light Rail interacts with traffic along major arterials (thoroughfares), but can also run on Fixed Guideways with dedicated right of ways.
Linked Trip:
Travel Demand Modeling term used to describe a trip from its beginning to its end regardless of the mode types (walk, bus, car, etc.) used.
Metropolitan Planning Organization (MPO):
A federally required planning body responsible for transportation planning and project selection in its region; the governor designates an MPO in every urbanized area with a population of over 50,000 people. There are 15 MPOs with responsibilities to Georgia, 3 of which are bi-state: Augusta (GA/SC), Columbus (GA/AL), and Chattanooga (TN/GA).
Mode Split:
The proportion of total person trips using various specified modes of transportation.
Mode:
A particular form of travel - e.g., walking, traveling by automobile, traveling by bus, traveling by train, etc.
Multi-Modal:
Refers to the availability of multiple transportation options, especially within a system or corridor. A concept embraced in ISTEA, a multimodal approach to transportation planning focuses on the most efficient way of getting people or goods from place to place, be it by truck, train, bicycle, automobile, airplane, bus, boat, foot or even computer modem.
Multi-Use Trail:
A paved or semi-paved facility that is separated from the roadway, and allows recreational or transportation activity by walkers, in-line skaters, skateboarders, or bicyclists. If such a trail occupies an abandoned rail bed, it is called a Rail Trail.
National Ambient Air Quality Standards (NAAQS):
Issued by US EPA and determines the amount of total emissions of criteria pollutants that can be produced in a geographic location by transportation facilities.
National Highway System (NHS):
Includes the interstate system, and other routes identified as having strategic defense characteristics as well as routes providing access to major ports, airports, public transportation, intermodal transportation facilities and routes of particular importance to local governments.
National Environmental Policy Act of 1969 (NEPA):
New developments must go through a “NEPA process” to determine the impacts and possible mitigation strategies to minimize negative effects on a region’s ecological support systems.
Network Year:
The year a project appears in the Transportation Conformity Determination model. A project shown in network year 2010 would be "open to traffic" by state fiscal year 2010.
Nitrogen Oxides (NOx) (pronounced "knocks"):
A group of chemicals which come primarily from combustion of fuels in cars and trucks, coal-fired power plants, industrial boilers and gas-powered engines such as lawnmowers and leaf blowers. Ground-level ozone forms during the course of the day as temperatures rise and VOCs and NOx react with each other on hot, sunny days. Ozone and particulate matter are the main components of what is called smog.
Nonattainment Areas:
Geographical areas, as defined by US EPA, whose air quality does not meet federal air quality standards designed to protect public health.
Non-Motorized Travel:
Travel accomplished by cycling or walking
Ozone – Ground Level (O3):
A colorless gas formed when Volatile Organic Compounds (VOCs) and NOx combine in sunlight. This "bad" ozone usually lingers at ground level and can cause respiratory problems especially in children and the elderly, and with adults who exercise outdoors. There is also "good" ozone in the stratosphere, which protects the Earth from the sun's harmful ultraviolet rays. Unfortunately, ground level ozone is not capable of providing the benefits of stratospheric ozone, nor can it migrate to a higher altitude to do so.
Parking Management:
Strategies aimed at making better use of available parking supply. Parking management strategies include preferential parking or price discounts for carpools and/or short-term parkers, and disincentives, prohibitions and price supplements for those contributing more to congestion.
Particulate Matter (PM):
Typically includes aerosols and fine solids, such as dust and pollen. Sources include factory and utility smokestacks, vehicle exhaust, wood burning, construction activity and agriculture. Ozone and particulate matter are the main components of what is called Smog.
PM2.5:
Particulate matter with a diameter less than 2.5 micrometers.
PM10:
Particulate matter with a diameter less than 10 micrometers.
People Mover:
A people mover operates within a major employment, residential or Activity Center area as the first or last leg of a commuter's journey. People movers generally circulate constantly with bus and rail stops.
Program:
A system of funding for implementing transportation projects or policies.
Regional Transportation Plan (RTP):
A 25 year transportation plan generated by input from counties in a Metropolitan Planning Area (MPA), and then compiled and modeled by the MPO.
Right of Way (ROW or R/W):
An area which usually holds the public utilities (both overhead and underground) and acts as a buffer between transportation infrastructure (for example-road or rail) and private property.
Smog:
A term used to describe visable air pollution; a result of the cumulative pollution effects of ground level ozone and particulate matter in the air we breathe.
Single Occupancy Vehicle (SOV):
A vehice on the road containing only one occupant, the driver.
Staggered Shifts:
This means that shifts are staggered to reduce the number of employees arriving and leaving a worksite at one time. For example, some shifts may be 8:00 a.m. to 4:30 p.m., others 8:30 a.m. to 5:00 p.m., and others 9:00 a.m. to 5:30 p.m. This has a similar effect on traffic as flextime, but does not give individual employees as much control over their schedules.
Traffic Calming:
Also called Traffic Management, this refers to various design features and strategies intended to reduce vehicle traffic speeds and volumes on a particular roadway. Examples include speed humps, traffic circles, on-street parking, bicycle lanes, and pinch points.
Transit Oriented Development (TOD):
Refers to residential and commercial areas designed to maximize access by transit and non-motorized transportation, and with other features to encourage transit. A TOD community has a center with a rail or bus station, surrounded by relatively high-density development, with progressively lower-density spreading outwards.
Transportation Control Measure (TCM):
A strategy to reduce driving or smooth traffic flows in order to cut auto emissions and resulting air pollution. Examples of TCM include HOV lanes, new or increased transit service, or a program to promote carpools and vanpools.
Transportation Demand Management (TDM):
A collection of low cost ways to reduce demand by automobiles on the transportation system, such as programs to promote transit, bicycling, flextime and ridesharing. These are often delivered by Transportation Management Associations and rideshare agencies. The acronym also sometimes stands for Travel Demand Management.
Transportation Enhancement (TE):
GDOT TE Site
A funding category created in ISTEA, and continued with TEA-21. Ten percent of STP monies must be set aside for projects that enhance the compatibility of transportation facilities with their surroundings. Generally, this means sidewalks, bike trails, and the hardscape of a road or corridor.
Transportation Equity Act for the 21st Centurty (TEA-21):
The Transportation Equity Act for the 21st Century was enacted June 9, 1998 as Public Law 105-178. TEA-21 authorizes the Federal surface transportation programs for highways, highway safety, and transit for the 6-year period 1998-2003. The TEA 21 Restoration Act, enacted July 22, 1998, provided technical corrections to the original law. The material presented on this web site reflects the combined effect of these two laws and refers to this combination as TEA-21.
Transportation Implementation Plan (TIP):
A three-year plan for regional transportation projects. A specific project must be in the current 25 year RTP in order to be included in a TIP.
Transportation Management Association (TMA):
A business-sponsored nonprofit organization that provides TDM activities in a well-defined business district, usually an activity center. In Atlanta, TMAs are operating in Perimeter, Buckhead, Cumberland, Town Center, Midtown, Downtown, the Airport, and the Clifton Corridor (Emory).
Unlinked Trip:
A point to point trip with no other stops or activities before or after.
Value Pricing:
A synonym for Congestion Pricing that applies when motorists are offered a choice between an unpriced but congested facility, and a Value Priced facility which provides a superior level of service. It emphasizes the extra benefits that users receive in exchange for paying a premium.
Vanpool:
A vanpool is a group of 7 - 15 people who commute together on a regular basis in a van. One of the riders volunteers to be the driver, and usually rides for free; the other riders pay a fee. Riders usually meet at a designated pick-up location like a shopping center parking lot or a park and ride location.
Vehicle Miles Traveled (VMT):
A measurement of the total miles traveled by all vehicles in the area for a specified time period. With TDM, it is usually used a measure of VMT avoided by shifting SOV users into other transportation options.
Volatile Organic Compounds (VOCs):
Vapors that emanate from paint and print shops, gas stations, dry cleaners, lawn chemicals, and from combustion engines, such as those in cars and trucks, boats and diesel locomotives. Trees also emit VOCs. Ground-level ozone forms during the course of the day as temperatures rise and VOCs and NOx react with each other. Ozone and particulate matter are the main components of what is called Smog. VOC emissions are a product of partial fuel combustion, fuel evaporation and refueling losses caused by spillage and vapor leakage. VOCs react with nitrogen oxides and sunlight to form ozone. Some VOCs are toxic and may be carcinogenic.
Acronyms
AFV |
|
Alternative Fuel Vehicle |
APTS |
|
Advanced Public Transportation System |
ARC |
|
Atlanta Regional Commission |
ATIS |
|
Advanced Traveler Information System |
ATMS |
|
Advanced Traffic Management Systems |
CAA |
|
Clean Air Act |
CFR |
|
Code of Federal Regulations |
CMAQ |
|
Congestion Mitigation & Air Quality Improvement Program |
CMS |
|
Congestion Management System |
CNG |
|
Compressed Natural Gas |
CO |
|
Carbon Monoxide |
DPF |
|
Diesel Particulate Filter |
EPA |
|
Environmental Protection Agency |
EPD |
|
Environmental Protection Division (State of Georgia) |
FHWA |
|
Federal Highway Administration |
FTA |
|
Federal Transit Administration |
GDOT |
|
Georgia Department of Transportation |
GEFA |
|
Georgia Environmental Facilities Authority |
GIS |
|
Geographic Information Systems |
GPS |
|
Global Positioning System |
GRTA |
|
Georgia Regional Transportation Authority |
HERO |
|
Highway Emergency Response Operator |
HOT |
|
High Occupancy Toll |
HOV |
|
High Occupancy Vehicle |
ISTEA |
|
Intermodal Surface Transportation Efficiency Act |
IT |
|
Information Technology |
ITS |
|
Intelligent Transportation Systems |
LDT |
|
Light-Duty Truck |
LRTP |
|
Long-Range Transportation Plan (also RTP - Regional Transportation |
MOE |
|
Measure of Effectiveness |
MPO |
|
Metropolitan Planning Organization |
NAAQS |
|
National Ambient Air Quality Standards |
NEPA |
|
National Environmental Policy Act of 1969 |
NOx |
|
Nitrogen Oxides |
RDC |
|
Regional Development Center |
ROW |
|
Right of Way (also R/W) |
SAQP |
|
State Air Quality Partners |
SIP |
|
State Implementation Plan |
SRTA |
|
State Road and Tollway Authority |
STIP |
|
State Transportation Improvement Program |
TCM |
|
Transportation Control Measure |
TIP |
|
Transportation Improvement Program |
TMA |
|
Transportation Management Association |
TMC |
|
Transportation Management Center |
ULSD |
|
Ultra-Low Sulfur Diesel |