|
Glossary of Definitions Glossary
of Acronyms
A B C D E F G H I J
K L M N O P Q R S T U V W
X Y Z
Portions of this glossary can also be found in the Federal
Highway Administration book, A Guide for HOT Lane Development.
Automatic Vehicle Identification
(AVI): A
technology system using transponders on vehicles and outside
sensors to determine
if vehicles on toll lanes are carrying a valid transponder
and what the vehicle’s classification is (truck vs.
passenger car, SOV vs. HOV). This system also processes the
appropriate toll transaction based on the information.
Auxiliary Lanes: Acceleration lanes and deceleration lanes
and other lanes associated with providing better access to
and from interchanges.
Benefit-Cost Ratio (BCR): The ratio of a
project’s
present value benefits to its present value costs. The BCR
is useful for comparing projects of different scale or financial
size since it assesses economic efficiency.
Bicycles/Pedestrian
lanes: Shared use lanes connecting residential,
retail, office and open lands for alternative transportation
usage.
Bus Rapid Transit (BRT): Could operate in a fixed guideway
physically separated from traffic, dedicated right of way,
Express lanes or HOV lanes.
Bus: Operates in general purpose travel lanes, express lanes
or HOV lanes.
Categorical Exclusion (CatX): A NEPA document
prepared for certain actions that are known through past
experience to
have no significant environmental impact and therefore “excluded” from
future NEPA processing.
Closed Circuit Television (CCTV): A video monitoring and
security system used to provide continuous traffic monitoring
by the facility operator along the length of the facility
and particularly at points of entry and tolling locations.
Return to Top Denver Regional Council of Governments
(DRCOG): The Denver
regional planning agency for transportation projects. The
Metropolitan Planning Organization (MPO) for the major metropolitan
area of Denver.
Detector Loops (Loop Detector Amplifiers): An AVC system
component imbedded in the pavement and used to detect and
classify the types of vehicles crossing over them. The loops
are linked to the lane controller and can be used individually
to count traffic or to trigger the violation enforcement
cameras or in tandem to measure vehicle speeds.
Differential Pricing (Variable Pricing): Time-of-day pricing
and tolls that vary by other factors like facility location,
season, day-of-week, or air quality impact.
Dynamic Pricing: Tolls that vary in real time in response
to changing congestion levels, as opposed to variable pricing
that tolls on a fixed schedule.
Economic Rate of Return (ERR): The economic
rate of return (ERR), sometimes referred to as the internal
rate of return,
gives the effective discount rate for which the project’s
benefits would just equal its costs, in present value terms.
In other words, it is the discount rate that yields a BCR
of 1.0.
Electronic Toll Collection (ETC): Systems deploying various
communications and electronic technologies to support the
automated collection of payment at toll booths and other
collection points. Collectively, the application of these
technologies increase system throughput, improve customer
service, enhance safety, and reduce environmental impacts.
Environmental Assessment (EA): An EA is a concise document
summarizing technical analysis to support the discussion
of alternatives and their associated impacts. If there are
no significant impacts, a Finding Of No Significant Impact
(FONSI) is prepared. The FONSI completes the NEPA process.
Environmental Impact Statement (EIS): An
evaluation of all reasonable alternatives that discusses
why other alternatives
were eliminated from the detailed study. The EIS also describes
mitigation measures that are required to be incorporated
into the implementation of the preferred alternative. The
EIS is only conducted if the anticipated impacts of the federal
action are found to be significant. A Record of Decision
(ROD) is prepared as the final decision of the preferred
alternative in the EIS.
Return to Top
Existing Conditions: Current
conditions and trends that include physical, environmental,
cultural
and social features. Basically, what is out there today.
Express Lanes (EL): A lane or set of lanes
physically separated from the general-purpose capacity
provided within major
roadway corridors. Express lane access is managed by
limiting the number entranced and exit points to the facility.
Express
lanes may be operated as reversible flow facilities or
bi-directional facilities. Express
Service: Point to point bus service, often from
a residential area directly to an employment center.
Express Toll Lanes (ETL): Managed express
lanes that every vehicle traveling on must pay a toll.
E-Z Pass: An electronic
toll collection technology deployed by a regional consortium
of transportation agencies
in
Delaware, New Jersey and New York. The technology is
compatible with similar systems used by tolling agencies
in several
northeastern states. Plans call for the deployment of
E-Z Pass on more than 700 toll lanes along 415 miles of
roads, tunnels
and bridges in the Northeast United States.
Fees
for Entering: These are tolls charged to vehicles entering
a particular facility or an area but which do not depend
on the distance traveled on the facility or in the area.
Fixed Pricing: Tolls
that remain the same throughout time; usually based on
distance.
Finding of No Significant Impact
(FONSI): A FONSI is the
decision document which completes the EA process.
General Purpose Lanes: Traffic lanes available for use by
the general public without any restrictions or tolls.
High-Occupancy Toll Lanes (HOT lanes): Managed, limited-access,
and normally barrier-separated highway lanes that provide
free or reduced-cost access to HOVs and also make excess
capacity available to other vehicles not meeting occupancy
requirements at a market price.
High-Occupancy Vehicle (HOV): A passenger vehicle carrying
more than a specified minimum number of passengers, such
as an automobile carrying more than one or more than two
people. HOVs include carpools and vanpools, as well as buses.
HOV Lane: An exclusive traffic lane limited to carrying
HOVs and certain other qualified vehicles.
Inherently Low Emission Vehicles
(ILEV): Alternative fuel,
clean air vehicles. Certain states (e.g. California) have
authorized the use of ILEVs in HOV lanes regardless of occupancy
(Assembly Bill 71). Related terms include Zero-Emission vehicles
(ZEVs), Ultra-Low-Emission (ULEV), and Super-Ultra-Low-Emission
(SULEV) vehicles powered by alternative fuels.
Incident Management: Managing forms of nonrecurring congestion,
such as spills, collisions, immobile vehicles, or any other
impediment to smooth, continuous flow of traffic on freeways.
Infrared Light Curtains: An ETC system component installed
in pairs to sense the separation between two vehicles passing
through a lane, as well as height depending on the number
of beams deployed. The information passed on to the lane
controller is used in conjunction with the loop detectors
to support the correct grouping of axles and to identify
large trucks or vehicles pulling trailers.
Intelligent Transportation Systems
(ITS): A broad range
of diverse technologies such as information processing, communications,
control, and electronics which can help transportation systems
in many ways, including congestion management.
Interoperability: The ability to provide of reciprocal privileges
for users of electronic toll collection systems on other
facilities equipped with ETC systems.
Return to Top Lane Controller: A microprocessor
ETC component that coordinates the activities of all equipment
in a single lane and generates
the transactions assigned to individual customers using that
lane.
Lane Management Tools: -
Access – Limiting
or metering vehicle ingress to the lane or spacing access
so that demand cannot overwhelm
HOT lane capacity. See also Limited Access.
- Eligibility – Limiting lane use to
specific types of users, such as HOVs motorcycles, low
emission vehicles,
or trucks. For most typical HOT lane settings, eligibility
requirements would be used during selected hours or at specific
access ramps.
- Pricing – Imposing a user fee on a
lane that helps regulate demand by time of day or day of
week. The fee increases
during periods of highest demand.
Level-of-Service
(LOS): Also known as “Traffic Service,” LOS
is a qualitative measure describing operational conditions
within a traffic stream. LOS is based on service measures
such as speed and travel time, freedom to maneuver, traffic
interruptions, comfort and convenience. LOS is also affected
by conditions such as number of access points, lane width,
number of lanes, and percentage of large vehicles. Six levels
of service are defined by letter designations from A to F,
with LOS A representing the best operating conditions, and
LOS F the worst.
Limited Access: Access management used to restrict entry
to a facility based upon facility congestion levels or operational
condition, such as the presence of an accident or maintenance
activities. Access may be restricted by 1) meeting signals,
or 2) limiting the number of entrances and exits. Some restricted
access lanes include HOV priority.
Light Rail Transit (LRT): Operates in a fixed guideway,
physically separated from traffic.
Local Service: Local bus service, often provides service
to a regional transit service station.
Managed Lane: A managed lane or lanes are designed and operated
to achieve stated goals by managing access via user group,
pricing, or other criteria. A managed lane facility typically
provides improved travel conditions to eligible users.
Metropolitan Planning Organization
(MPO): Federally mandated
regional organizations responsible for comprehensive transportation
planning and programming for in urbanized areas. Work products
include the Transportation Plan, the Transportation Improvement
Program, and the Unified Planning Work Program.
Mileage-Based Fee: A vehicular toll based on the vehicle
miles traveled (VMT) in the jurisdiction.
Mixed-Flow: Combined flow of HOV vehicles and SOV vehicles.
Mobility Enhancement: Features
or facilities that aid in moving people or goods. Mobility
enhancements are often implemented
in conjunction with capacity improvements.
Motor Vehicle Fuel Tax: Federal and state taxes levied on
gasoline and other fuels.
Return to Top National Environmental Policy Act
(NEPA): A national policy set for the protection of the natural
environment and human
health and welfare by promoting efforts to prevent or eliminate
damage to the environment. From a transportation perspective,
NEPA requires that alternatives be evaluated and decisions
be made in the public’s best interest based on a balanced
consideration of the need for safe and efficient transportation.
No Action: An
alternative that is used as the basis to measure the impacts
and benefits of the preferred alternative(s)
in an Environmental Assessment or other NEPA action. It consists
of the existing conditions on the roadway, plus any safety
or maintenance improvements which have been identified in
the CDOT 5-Year Transportation Improvement Program.
Open Road Tolling: Fully automated electronic tolling in
an open road environment allowing vehicles to travel at normal
speeds when passing though toll collection points.
Price Elasticity of Demand: A measure of the sensitivity
of demand for a commodity to a change in its price. It equals
the percentage change in consumption of the commodity that
results from one-percent change in its price. The greater
the elasticity, the more price-sensitive the demand for the
commodity.
Queue Jump: Elevated ramps or at-grade lanes that can be
used by motorists stopped in traffic to bypass congestion.
Record of Decision (ROD): The decision document in an Environmental
Impact Statement (EIS).
Reversible Flow: Lanes that can be operated in reverse direction
to reduce congestion during certain peak periods.
Revenue Neutral: Revenue-neutral pricing strategies involve
rebating some or all of the revenue generated by pricing
to toll payers, where generating revenue is not an objective
of value pricing.
Road Pricing: An umbrella phase that covers all charges
imposed on those who use roadways. The term includes such
traditional revenue sources as fuel taxes and license fees
as well as charges that vary with time of day, the specific
road used, and vehicle size and weight.
Safety and Maintenance Improvements: Projects
included in CDOT's 5-Year Transportation Improvement Program,
completed regardless of a study's outcome.
Screening
Criteria: Screening
Criteria are used to compare alternatives. Often, there
are two or three levels of screening
that are needed, depending on the complexity of the project
and the range of alternatives under consideration.
Single Occupant Vehicle (SOV): A vehicle occupied by only
one person.
Return to Top Time-of-Day Pricing: Facility tolls that vary by time-of-day
in response to varying congestion levels. Typically, such
tolls are higher during peak periods when the congestion
is most severe. Many sectors of the economy (telephone, electric
utilities, and airlines) use such pricing to manage demand
within the available capacity.
Toll Road: A road or section of road where motorists are
charged a fee (or toll).
Toll Violation Camera: Fixed, short range, still cameras
used to obtain single frame pictures which are deployed in
individual lanes at tolling points. Toll violation cameras
are aimed and focused to obtain images of the license plates
of violating vehicles.
Transponder: An electronic tag mounted on a license plate,
built into a vehicle, or placed on the dashboard. The tag
is read electronically by an electronic tolling device that
automatically assesses the amount of the user fee.
Transportation System Management
(TSM): Strategies to improve
the efficiency of the transportation system through operational
improvements such as bus priority lanes, ramp metering, access
management, Intelligent Transportation Systems, etc. TSM
techniques improve system capacity without physical expansion
or
behavioral changes.
Return to Top
Travel Demand Management (TDM): Strategies
designed to make the most efficient use of existing transportation
facilities
by reducing the actual “demand” placed on these
facilities. These strategies promote alternative modes, increase
vehicle occupancy, reduce travel distances and ease peak-hour
congestion. The TDM efforts can extend the useful life of
transportation facilities and enhance mobility options.
Treadle: A pressure-sensitive device inserted in the pavement
designed for directional counting of vehicle axles passing
over them. These sensors are used as inputs to the lane controller
to provide information on axle count and vehicle direction
of travel, depending on the order in which are stripes are
hit.
User Management: User management defines how and which types
of users can utilize a facility, such as HOV occupancy requirements,
access points, barrier separation, and user fees. Restrictions
may vary by time of day or day of the week.
Value Pricing: Value pricing is a concept that uses monetary
incentives to manage congestion during peak travel periods
on tolled highways and crossing facilities.
Variable Message Signs (VMS): Electronic signage that employs
ITS technology and centralized control systems to change
messages in real-time, providing motorists with timely and
useful information.
Variable Pricing: Fixed
tolls that are based on time of day and used to manage
congestion during peak travel periods.
Vehicle Hours Traveled (VHT): Total vehicle hours expanded
traveling on the roadway network in a specified area during
a specified time period.
Vehicle Miles Traveled (VMT): The measurement of the total
miles traveled by all vehicles in a specified area during
a specified time.
Vehicle Enforcement Systems (VES): Manual and computer systems
used to enforce vehicle and motorist compliance with the
usage guidelines for HOT lanes.
Vehicle Separators/Profilers: An AVI system component located
on a gantry or at the side of a lane. They perform functions
similar to light curtains. The class of vehicles is determined
based on the profile of the passing vehicle.
Video Surveillance: The
use of pan-tilt-zoom, steerable moving picture cameras
to survey a toll plaza, ETC collection
area, or a segment of roadway to monitor for incidents.
Return
to Top |
