Parkings where people forming a carpool can meet and riders may park
their car/motor_cycle/bike, called "carpool parking" hereafter.
I propose to extend the values for tag park_ride by 'hov' (high
occupancy vehicle) to tag such parkings.
Carpool parkings are currently tagged very differently. A specific value
would allow to render such parkings with a proper symbol and use them as
meeting points in intermodal trip planners. In contrast to using a
different tag like carpool, carpool_parking or amenity=car_pool, the
proposed tagging would fit well in the semantics of the park_ride tag:
leaving a car to ride a different transport mode.
Tags like carpool=yes, carpool=designated, hov=yes, hov=designated IMHO
should be used, where (already formed) carpools/hovs are allowed or
required, like workplace parkings reserved for high occupancy vehicles
with 2+ passengers.
Thank you for all of your comments, criticisms and suggestions