Downtown, traffic is often congested, parking is always expensive or problematic, and the Vespa is a very effective solution to both.
On holiday trips, I started to realize it is actually one of the best vehicles to discover the world :
* riding on a motorcycle (or bike) allows to experience the landscape and scenery in a more intense way (compared to car, bus, train,..)
* it's speed is slow enough to be able to experience everything, yet fast enough to make some progress through the day
* it's not too expensive
The only disadvantage or problem is that you can't really take a lot of luggage with you : there is a small rack at the back, but it only accomodates a small bag. In front of the driver is a hook, which will hold a small rucksack.
I really needed more storage, either for equipment on profesisonal jobs, or for camping gear during the holidays.
After seeing some examples of single-wheel trailers for bikes and scooters, I decided to make a multipurpose-trailer for my Vespa
Given the complexity of this project, and the safety (and road-legal) requirements, this was going to be a project which would take several months. Your needs and capabilities are likely to be different, and so you probably won't be able to build one yourself simply following this instructable. Still I hope that this story may help and inspire you to build one, some day.
Good luck & Hope to meet you on one of my trips one day !