Trajectories are for ballistics

The path taken when an unpowered object is thrown, resulting from the physics of gravity. It can be extended metaphorically to other upward progressions (such as a career), but shouldn’t be used as a generic, high-falutin’ synonym for a route or pathway.

Many other languages have a similar word with a similar meaning to the Dutch traject (pretty much any route or non-physical pathway) and as a result it’s a common Eurospeak term. In English, you should stick to alternatives such as route, path or pathway.

• a bus or train can’t have a trajectory, unless it’s fallen off a bridge
• a patient can’t have a trajectory through the healthcare system
• a computer package can’t have a development trajectory

It’s got the same root as Utrecht and Maastricht, by the way: trajectum or river crossing – supposedly originally a spot where you could throw a spear across.

Prevalence: moderate. The Dutch word traject is quite a popular buzzword.
Frequency: high. Dutch writers will rarely put anything other than trajectory for traject.
Native: sometimes. It sounds nice, doesn’t it? The Eurospeak use is gaining currency.