The Greenspeed range of HPVs is built in Melbourne, Australia, by Ian Sims, Unit 5/31 Rushdale Street, Knoxfield Victoria 3180.
Basic layout of the trike is similar to that of the UK Windcheetah and Trice: single rear driving wheel and two front, steering, wheels. Frame is of Reynolds 531 or 4130 CroMo, and the steering is based on the Ackermann principle. Braking is by Sachs drum brakes on the front wheels — very effective.
There are now mny versions, including tandems. Prices vary according to equipment — a range of componentry is available.
Mine is one of the early versions (1991), with 26″ rear wheel, and seat frame separate from the main frame. It sometimes has a front fairing in place. It’s worth a couple of km/h on the straight and level, but does add weight and makes getting on and off a bit awkward. Object over the rear wheel in the picture above is a board with shock cords for carrying a backpack as a pannier.
The fairing is of balsa/glass fibre sandwich construction (what did you expect from a canoe and kayak builder?) and is supported by the main strut of L section aluminium strapped to the frame, and three smaller struts. Weak link is the strap around the central tube: the original aluminium strap quickly fatigued — the stainless steel one took a little longer to fail.
Riding a recumbent trike is, well, different. The seating position is comfortable and relaxed, but the pedalling action is sufficiently different to require acclimatisation. Stopped, you can keep your feet on the pedals (clipless (e.g. SPD) are essential) without falling. On slippery surfaces you are unlikely to go over, but it’s not hard to lift a wheel if you take roundabouts too fast. Riding in the wet is like sitting between two sprinklers.
Climbing hills is a bit slow, because it is a somewhat heavy machine. Downhill...
As for other traffic, most motorists haven’t a clue what it is and give it a wide berth.
For more details, take a look at the Greenspeed Web page.
My other HPVs have two wheels.