Spent the days chilling at my local game store working on Traveller thoughts. Took the 1e and 2e Vehicle Handbooks to study. First, I found the Grav Utility Vehicle and I'd say that is a very close representation of a grav based upgrade for the ATV. Quite a few other useful g-craft designs to covert.
My biggest exercise was the idea of a mass transit or freight grav vehicle, a grav train/subway/etc.. I originally proposed a train like design with modular 'cars' that could be added or subtracted as needed. I listen to my techno rave and decided to focus on mass transit, the whys and hows. I thought about why would you need such a thing in an environment of grav vehicles whizzing everywhere and realized they won't be. I thought about sci-fi examples and you frequently see lines of slow but orderly streams of vehicles in three dimensional tight lanes. Even the Jetsons' world did that. Your grav craft might be inherently quick but you do not open it up full unless you're a jedi chasing assassins. Within city limits, grav vehicles are highly restricted in speed and location. More than likely, high density populations will normally demand control. You probably will move no faster than Slow band, will be guided into traffic flow and automatically guided to a destination where you regain control. There are some of the issues. First, not everyone can have access to personal grav vehicles and second it can take a lot of time to get around. This is where high density people movers come in.
I poured through both vehicle handbooks and rediscovered 1e had rules for 'rail' designing including grav rail systems riding on repulsor rails similar to maglevs. Took some time to understand what I needed but I decided the optimal rail is akin to Light Rail Vehicle. Each car is an independent unit that can be linked together to handle as many passengers as needed. The most important qualities are they move at high speeds up to 500 km/hr compared to local traffic, use external power (no range limit) and are fully automated. The rail system is monitored and relay information to the train. Trains have minimal crew cabs for emergencies or necessary manual control and an autopilot is back up in emergencies to bring the train to safety. The cabs are enclosed and sealed against the elements and even high altitude.
Light Grav Automated Transport System
TL 11
Skill Flyer (Grav)
Agility -1
Speed (Cruise) Fast( - )
Range ( - )
Crew 0 (1 emergency)
Passengers 36
Cargo 1
Hull 160
Shipping 40
Cost Cr.6,617,700
Traits: None
Equipment: Control system (Basic), Autopilot (Flyer +2), External power (Grav vehicle),
Communication system (Basic, encrypted), Sensors (Basic), Life support (Short term), Robot brain (Advanced)