Alignment—the movement of a roadway
through the landscape; its curves, straight sections and
Arterial—a roadway providing the
principal high-volume and high-speed linkages within a community
and between communities.
Avenue—a broad urban thoroughfare,
Boulevard—a broad urban thoroughfare,
usually tree-lined and with a broad median.
Clear zone—the recommended area
alongside a roadway clear of all potential hazards (something
an automobile might strike) such as trees, rocks, utility
poles and the like. The recommended width of a clear zone
varies based on the functional classification of the road.
Collector—a roadway providing service
between arterials and local roads.
Designed landscape—a landscape,
or the alteration or modification of the natural landscape,
that has been created specifically to provide a desired
experience (usually aesthetic) to the user or a community.
Designed landscapes are generally created by a landscape
architect, planner, architect or other design professional.
Design speed—the maximum safe speed
at which a vehicle can be expected to operate on a roadway.
The speed for which a roadway is designed—this may
not be the posted speed.
Errant vehicle—a vehicle leaving
the roadway in a reckless or uncontrolled manner.
Expectancy—a theory, based on a
motorist’s “knowledge stores” of driving
experiences, that suggests predictable driver responses
to familiar situations and settings. Routine experiences,
such as sufficient merging space at the end of a freeway
ramp, become unconsciously established in the driver’s
mind—thus creating conflict should the “expectancy”
not be met.
Galvanized steel—a zinc coating
applied to steel to prevent rusting. Galvanized steel has
a flat chalky-gray appearance.
Guardrail—a barrier, usually of
a post-and-beam construction located alongside a roadway,
in medians and in front of hazards to prevent an errant
vehicle from striking an obstacle or encountering a dangerous
slope or drop-off.
Horizontal alignment—the movement
of a roadway to the left or right; its curves.
Integrity—the current quality of
a feature or element when compared to its original quality.
Jersey barrier—a angled concrete
barrier designed to guide an errant vehicle back to the
roadway and guard against hazards.
Lane—a narrow passage (or road)
defined by buildings, hedges or fences.
Liability—an obligation to perform
a specific duty.
Limited access—a concept whereby
the entrances and exits of a roadway are restricted to certain
locations—generally to allow for higher speed traffic
movement due to the absence of cross streets and intersections.
Local road—a roadway serving adjacent
residences and businesses—generally of low-volume
Median—a central space, often planted,
dividing opposite moving travel lanes.
National Register of Historic Places—a
national listing of sites meeting the U.S. Secretary of
the Interior’s standards, maintained by the National
Neat line—an imaginary line representing
the average face of an irregular surface, such as a stone
Park road—a road through a park.
A park road in an element within a park.
Parkway—a roadway contiguous with
or linking park spaces. In its truest definition, a parkway
provides access to recreational, scenic or leisure spaces.
Post and cable guardrail—a guardrail
constructed of regularly spaced posts connected by a flexible
(usually steel) cable.
Posted speed—the speed at which
a roadway is signed. This is usually, thought not always,
lower than the design speed.
Realignment—the repositioning of
a segment of a roadway.
Reinforced concrete—concrete with
a steel reinforcing framework. Reinforcing enables the concrete
to perform in structural situations. Concrete by its nature
resists high compressive loads (the heavy weight of a truck,
for example). Steel reinforcing resists high-tensile loads
(the pull to the left or right one would encounter on a
bridge, for example).
Right-of-way—the land area dedicated
to or associated with a roadway that is owned or managed
by the road management entity—including the roadway,
shoulder and affiliated landscape.
Shoulder—a stabilized level area
adjacent and parallel to the roadway that provides a recovery
space for an errant vehicle or a safe space for a disabled
Sight distance—the length of roadway
ahead that is visible to the motorist.
Standards—the legally adopted policies
and practices directing the design and construction of a
Street—an urban thoroughfare, usually
defined by buildings.
Superelevation—the banking or sloping
of a road curve to enable vehicles to maintain a speed consistant
with the overall speed of the roadway. The banked ends of
racing tracks represent an exaggerated superelevation.
Taking—in legal terms, the direct
acquisition of property, or the implementation of policies
or actions that significantly impact a property.
Tort liability—a situation in which
an injury or harm has occurred, due to a breach of a preexisting
duty or obligation, resulting in potential exposure to an
individual or organization for damages.
Vertical alignment—the movement
of a roadway up and down; its hills.
Volume—the number of vehicles a