Bike Trailers
Trailer Bikes
On Demand Tandem

One-Wheeled Trailer Bike: fun for the child and peace-of-mind for the parent (Photo: chicagobikeblog.com)
As an infant grows into a young child, a trailer bike like that illustrated above can be used in place of a child trailer by the parent or guardian to safely cycle with the child in tow.
One-Wheeled
Most trailer bikes are one-wheeled children's bikes that attach to the seatpost or rear luggage rack of a full-sized upright bicycle turning the bike into a tandem on demand. and can be used by children as young as four years of age whether they pedal along or not.

One-Wheeled Double Trailer Bike: can provide a family with car-free mobility (Photo: carfreedays on flickr)
Two-Wheeled

Two-Wheeled Trailer Bike: more fun for the child and flexibility for the parent (Photo: via nihola.de)
Some models use a bracket (not unlike on single-wheel touring trailers) that attach to the bicycle's rear stays (as shown above) to enable a child's standard upright bicycle with 16 and/or 20 inch wheels to be towed. The benefit of this being that a parent or guardian can guide the child through city traffic with the bike attached until reaching a park where the child's bike can then be unhitched, allowing the child to cycle along the park's paths free of motorized traffic.
Special Needs

Caboose: two-wheeled trailer bikes provide benefits for people with special needs
(Photo: 5minutesformom.com)
Two-wheeled trailer bikes have been developed for those with special needs and are ideally suited to persons -young or old- with balance problems.
Keywords
trailer bike, parent, guardian, child, youth, special needs, adult, bicycle, towing,
