J. Balwin, tech editor for Whole Earth, says that it takes 3 tries to get to something you want to use. The first prototype illustrates the big flaws, and the third one is getting close to what you originally intended, after some practise making the bits. I like to take big bites in design work too, but that just gets me to some new features for the 3rd version.
Car Cycle includes details on a front suspension geometry that uses offset for trail instead of caster angle, which turned out fine, despite no prior art. The integrated suspension was fine, too. It was only intended as a test bed, but would have gone a lot farther except for not being planned for easy maintenance. I saved a lot of weight on a similar body for another chassis, though, probably less than half the original's weight.
Tippy delta trikes are much safer where they are common, and traffic patterns meet their limitations, although road safety in those areas is appalling by North American standards. Have a look at the astronomical insurance rates for Harley trikes over here.
Re: freeway shoulders. In "Zen and the Art of Motorcycle Maintenance," Robert Persig reveals his way to plan a cross-country trip. On a map, squiggles are good. That means hills and scenery. The best riding is on a road that goes from nowhere to nowhere, with an alternate route that gets there faster. The kids wave at you, and the adults have time to chat. Always plan on answering questions for five minutes on your way into a store.