I set up a popular metro circuit. I received a notification that my ticket prices were too low. I go to the ticket prices window. I see that the Metro monthly ticket price for all zones is deep blue. I raise the price to remove the notification. The monthly price for all zones (bottom-right-most corner) is capped at 500 money units per month. The game still requests that I raise the price, even though I cannot (it is still light blue at 500 money units per month and I occasionally get a "ticket prices are too low" notification).
As a side note, it seems that if the ticket prices are there to notify the player of potential issues with each line, it seems redundant to have both daily and monthly ticket prices to change. It is twice the work without any added benefit since the game apparently calculates the monthly price by multiplying the daily price by 30.
As a side note, it seems that if the ticket prices are there to notify the player of potential issues with each line, it seems redundant to have both daily and monthly ticket prices to change. It is twice the work without any added benefit since the game apparently calculates the monthly price by multiplying the daily price by 30.