"Ninety-five percent of the time, they don't do it, " said Althea Outten, an MTA agent working at the Bowling Green subway station this week, referring to parents and youths taller than 44 inches who don't swipe.

WSJ: Little Ones, the Subway and the Law

Bowling Green is the only subway station that has one: Near the turnstiles at every subway entrance is a blue sign with a yellow ruler.

WSJ: Little Ones, the Subway and the Law

The city buses are colour-coded to instantly telegraph what type of route they ply: red buses are express, green buses run short routes between subway stations and other points.

BBC: Living in: Great cities for public transport

You can take your bike on any of the MBTA subway lines except the green and silver lines, but you must avoid rush hours (7 am to 10 am and 4 pm to 7 pm weekdays) and always ride on the last train car.

BBC: Boston��s great outdoor adventures

That, it turns out, is where green-tech wonders like the Segway work best--and where the subway works even better.

FORBES: Magazine Article

In green transportation news, LA Metro announced an exciting new program that will harvest energy from subway trains.

ENGADGET: Inhabitat's Week in Green: self-sustaining homes, wooden wind turbines and the world's first solar-powered nation