Vogon Contructor Fleets are large, yellow, ugly, and generally reviled across the galaxy.
Despite their name, the Vogon Constructor Fleets are more likely to deconstruct whatever they come across, rather than actually construct anything. They do this not out of any kind of malice, but rather from the sheer beaurocratic bloodymindedness of it.
Also, the sheer ugliness of these fleets lowers realestate prices in their vicinity considerably. Vogon Constructor Fleets can make a considerable profit by being paid to not be in certain areas of the galaxy...
Recommendation: Do not attempt to HitchHike on any Vogon Fleet. Especially Constructor Fleets.