These "bike trains" have nothing to do with railroads and locomotives. Rather, they are scheduled group rides intended to make it easier for adults to commute to work or for kids to bike to school.
The whole idea behind these "bike trains" is safety in numbers. For example, in England, they organize twice daily “bike trains” for bicycle commuters who have to ride along a very busy stretch of highway between Brighton and Sussex University. The group takes up an entire lane on the highway and the last bike carries a large sign which indicates the existence of the "bike train". This bike-train operation has scheduled departure times and is supported by its own website.
In the States, some schools have started organizing “bike trains” as a way to allow children to safely bicycle to school. Under adult supervision, the group will ride around a neighbourhood picking up kids who want to bicycle to school. It’s a great way for kids to get to school on their own and it encourages them to be more physically active.
Click here for a news report about the "bike train" for commuters in England.
Click here for the "bike train" website in England.
Click here for more about using "bike trains" to get kids to school in the US.