Start with households by vehicle tier
A total vehicle count is not enough. Use current management records to count households with two, three, and four or more vehicles.
Record no-car and one-car households separately when they are not charged, and decide how exemptions and operational vehicles are treated.
- Two-car households
- Three-car households
- Four-plus-car households
- Exemption and registration rules
Use the same fee definition for both policies
The calculator treats each entered fee as the total monthly amount paid by one household in that tier, not a price for every vehicle.
Label Policy A as the current plan and Policy B as the proposal, then apply both to the identical household counts.
Example: 180 households at 10,000 won
Charging 180 two-car households 10,000 won produces 1.8 million won per month and 21.6 million won per year from that tier. A 20,000-won alternative produces 3.6 million won per month.
Repeat the calculation for higher tiers and add them to compare total monthly and annual revenue.
- Monthly revenue = households × monthly household charge
- Annual revenue = monthly revenue × 12
- Policy difference = Policy B - Policy A
Revenue is not the same as parking improvement
Higher fees do not create physical spaces. Measure registration and overnight occupancy on the same basis before and after implementation to assess behavior change.
Unregistered vehicles, exemptions, arrears, and ownership changes are excluded. Review bylaws and the required decision process separately.