Japanese cities have numerous small vacant-lot parking areas. In many ways, these are a blot on the landscape and are part of an oversupply of parking in small Japanese cities.

But at least most are priced and open to the public via so-called ‘coin parking’. This refers to self-service (unstaffed) paid parking using ‘flap lock’ systems.

These flap lock parking systems do not require on-site staff and have low enforcement costs, which keeps operating costs very low.

In the areas in Japanese cities that have high market prices for parking, the low cost of coin parking makes such systems feasible on even tiny parking lots with as few as one or two spaces.

Flap lock parking systems involve a flap lock device installed across each parking space. When a car parks on the space, a flap rises after a short delay (such as 2 minutes). This prevents the vehicle from driving off. Upon returning, the motorist makes payment (usually at an on-site kiosk or via digital payment app). This causes the flap to lower again, allowing the vehicle to be driven away.

In the past, only coins were accepted in most coin parking lot kiosks. However, other payment methods, such as payment by digital app, pre-paid contactless cards and credit cards, are increasingly accepted.

Coin parking using flap lock systems arose as a business innovation with no government involvement. However, the system did arise to take advantage of the lack of government regulation over small parking lots in Japan and from Japanese parking policies that made paid parking a viable business in most areas of most Japanese cities. These policies include having parking mandates (minimums) that are set at very low levels and which exempt small and medium-sized buildings and allowing very little on-street parking (and none at all overnight).