No, fleet is a common noun.
Proper nouns always start wit a capital letter and are the names of people -- John, Mary or the names of countries and cities -- Paris France or the names of organizations or companies -- Harrod's MacDonald's
The general collective noun for 'vehicles' is a fleet, for example:a fleet of carsa fleet of taxisa fleet of limosa fleet of trucksa fleet of buses
The collective noun is a fleet of luggers.
The noun 'fleet' is a standard collective noun for:a fleet of aircrafta fleet of planesa fleet of shipsa fleet of taxisa fleet of carsa fleet of lorries (trucks)a fleet of printersa fleet of bassa fleet of cootsa fleet of mud-hensa fleet of pigs
The noun 'fleet' is used as a collective noun for planes, ships, and motor vehicles; for example:a fleet of carsa fleet of taxisa fleet of shipsa fleet of planesa fleet of trucks
The collective noun is a fleet of trawlers.
"Underground river" is a common noun that refers to any river that flows beneath the surface of the Earth. It is not a specific or proper noun unless referring to a specific, named underground river such as the Puerto Princesa Underground River in the Philippines.
Depending on how you use it general can be a proper or common noun. Example common noun: That man is the general of his fleet. Example proper noun: General Washington was later made president.
The general collective noun for 'vehicles' is a fleet, for example:a fleet of carsa fleet of taxisa fleet of limosa fleet of trucksa fleet of buses
The collective noun is a fleet of luggers.
The noun 'fleet' is a standard collective noun for:a fleet of aircrafta fleet of planesa fleet of shipsa fleet of taxisa fleet of carsa fleet of lorries (trucks)a fleet of printersa fleet of bassa fleet of cootsa fleet of mud-hensa fleet of pigs
The noun 'fleet' is used as a collective noun for planes, ships, and motor vehicles; for example:a fleet of carsa fleet of taxisa fleet of shipsa fleet of planesa fleet of trucks
The collective noun is a fleet of trawlers.
The collective noun 'fleet' is used for groups of vehicles: a fleet of ambulances.
The collective noun for luxury cars is the same as the collective noun for any type of car, a fleet of luxury cars.
There is no standard collective noun for police cars.The standard collective noun for police is a posse of police.The standard collective noun for cars is a fleet of cars.When there is no specific collective noun, any noun that suits the situation can be used, for example a chase of police cars, a procession of police cars, a swarm of police cars, etc.
The word 'fleet' is a singular, common, concrete noun; a word for a thing.The noun 'fleet' is a collective noun for a group of ships or vehicles that move together or are under one management; a group of warships under one command.The word 'fleet' is also an adjective.
"Park Avenue" is a proper noun, because it is a place. Proper nouns like this should always be capitalized.