GLOSSARY :: www.henryhudsonparkway.org
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
AASHTO. American Association of State Highway and Transportation Officials aka the Green Book. (Available from the Government Printing Office.)
Acceleration and deceleration lanes. Extra lanes created at entrances and exits to allow vehicles to adjust speed.
Alignment. The layout of the road across the landscape. Parkway alignment makes use of curves, dips and rises to provide the motorist with a changing sequence of scenic views as well as to limit speed. Realignment of a historic parkway can seriously degrade its design integrity.
Authority. A quasi-public agency with jurisdiction over a public resource. E.g., the Metropolitan Transportation Authority (Triborough Bridge and Tunnel Authority) has jurisdiction over the Henry Hudson Bridge and its approaches from Kappock St. in the Bronx and Dyckman in Manhattan. The New York Port Authority has jurisdiction over the George Washington Bridge and its approach roads and parkland. The authority was by Robert Moses to
Bicycle Lanes. In NYC, a Class 1 bike lane is physically separated from traffic; Class 2 is a delineated lane in the street; and Class 3 is marked only by signs indicating it is a recommended route for bicycling.
Clear zone. Area alongside a roadway free of potential hazards.
Context. The area surrounding a roadway that helps define its character. It may include destinations and neighborhoods along the route that while not directly visible from the road are easily accessible.
Designed landscape. Area that is either planted or deliberately maintained to create a specific effect.
Design speed. The maximum safe speed at which a vehicle can be expected to operate on a roadway (almost always substantially higher than the posted speed limit).
Guardrails. Barriers along the edge of the roadway to protect something from the impact of an errant vehicle. DOT now prefers to use the word guide rail, because they are now designed to deflect as well as absorb the impact from a collision. While the most common rail on the Henry Hudson Parkway is now galvanized steel W beams, it also preserves original ornamental green steel fencing in Manhattan and rustic wooden rails in the Bronx.
Grade separation. Use of different levels. Grade separation of north and south bound lanes at different levels can eliminate oncoming headlight glare and preserve a scenic view. Grade separation of intersections carries traffic over or under a highway, making it "limited access."
Jersey barrier. Concrete barrier designed to guide errant vehicles back into the roadway.
Jurisdiction. Ownership and ultimate responsibility.
MUCTD. Manual on Uniform Traffic Control Devices for Streets and Highways. Establishes national standards for all traffic control devices (including signs) on any street, highway, or bicycle trail open to public travel. (Available from the Government Printing Office)
National Highway System. Interstate and national primary arterial network. All roads are required to meet Federal Highway Administration standards.
Parapet. The sidewall of the upstairs of a bridge.
Right-of-way. The land area of the corridor proper, including the roadway as well as the green buffers.
Shoulder. Level area adjacent to roadway for disabled vehicles.
Sight distance. The length of road ahead that is visible to a driver.
Standards. The legally adopted policies and practices directing the design and construction of roads.
Stormwater catchment area. Area on which precipitation falls and is either absorbed by soil, where it can irrigate the landscape, or channeled into storm drains and into the river, along with pollutants. Impermeable surfaces, such as pavement, divert water from the landscape to the drainage system.
Tort liability. A situation is which an injury or harm has occurred, due to a breach of a preexisting duty or obligation, resulting in potential exposure for damages.