The way parkings works in US and in particular in Manhattan is way far from how it does in Europe.
You do not park your self your vehicle, access is often the same for entry and exit, licence plates are not standard (font can be different in each state) etc..
The issues :
Use innovative systems as Licence Plate Recognition, ticketing and modern POS to automate as much as possible the operations in a garage for parking business, reduce fraud and have a real time vision on traffic and incomes.
Integrate same system in each garage that keeps their specific configuration (infrastructures, employees, monthlies, pricing).
The WebApp :
Design and development of a centralised WebApp to manage all operations in 120 garages for more than 10 000 Parking spots.