Users have to sign up in advance - at a cost of £3, about $4.70 - for an electronic key to unlock the bikes. (Eventually, cyclists won't need to register ahead of time.)
From there, users pay a relatively small membership fee (ranging from £1 for a day to £45 for a year), and a usage fee that rises along with the length of the ride. The first half-hour is free. It's £1 for an hour-long trip, £4 for an hour-and-a-half, £6 for two hours - up to £50 for a 24-hour rental.
Riders can return the bikes to any docking station, which aren't hard to find - little more than a few hundred meters separates them in the busiest parts of central London. The bikes will be monitored every few weeks for any needed maintenance.
The launch was largely successful. Tens of thousands have signed up already. One of the most indelible images after a weekend in London are the blue bikes we saw everywhere.
They're stylish, sturdy and smooth. They weigh a little more than 50 pounds - which, besides softening the ride for inexperienced riders, is meant to help temper the theft problem that plagued bike-sharing in Paris.
That gets at the best part of the program: Boris Bikes aren't built for Lance Armstrong. They're meant for casual riders looking for an easy, cheap way to get around a crowded city.
The notion of bike-sharing in Philly may sound familiar to you. What I didn't appreciate until my return was that there was a feasibility study paid for by the William Penn Foundation and released in February that found that Philadelphia has several key factors - geography, weather and commuting patterns among them - in common with bike-sharing cities like Paris and Barcelona.
