A $1 fare grants them unlimited rides throughout the day.

And if you already have a Metrocard good for unlimited rides, the trip is free.

The current base fare is $1.75 for 90 minutes of unlimited rides.

For about $14.80, it offers seven days of unlimited rides within central London on both trains and buses.

They can also purchase passes for unlimited rides for given number of days.

But the stakes could get higher when a 30-day pass for unlimited rides, costing $63, is introduced on July 4.

No transfers are given, but a 24-hour pass good for unlimited rides costs $4.00.

Monthly pass - allows unlimited rides for an entire month.

Your ticket buys unlimited rides all day; ride is free for senior citizens.

Ticket prices eventually increased to allow visitors unlimited rides throughout the day.