Some notes on technology.

I'm used to technology levels in GURPS, which are a bit different to those in Traveller, so I've clarified things here for my own use, for what a typical culture of a given tech level would be like.

Note that I assume that a Tech Level is pretty much what a world can produce or at least maintain itself, not necessarily what is available. A world on a major trade route will tend to have easy access to whatever technology is available on neighbouring worlds, at least for small scale commercial items.

TL 0-2 are pre-industrial revolution. The only technology available will be what comes in from outside.

Civilisation will be tribal, warring kingdoms and the start of massive urbanisation.

Industrial revolution, 19th century Earth. Horse and steam power.

Mechanisation and basic chemistry and medicine, early 20th century. Basic cars, common (but expensive) international travel, air craft and big cities. Telecommunications will be widespread, but not ubiquitous.

Nuclear power, early mechanical computers. Big cities and common air and sea travel. 1950s Earth.

Basic computer technology, heavy urbanisation and the growth of cities. Late 20th century Earth.

Early 21st century Earth. Mobile communications are ubiquitous, air travel is cheap. Glass and concrete cities.

Beginning of interplanetary travel with gravitics, industry beginning to move into orbit.

Cities are very much like early 21st century, but air cars are beginning to become available, with affordable space travel. Colonisation of asteroid belts and other worlds greatly expands access to resources.

The first jump drives become available. Small holographic displays are possible, so street signs might be holographic.

Phasing out of fossil power almost complete as fusion becomes available and practical on a large scale. Most vehicles and machines run off electric, with direct connection to the grid or battery power.

Cities are power hungry, climate engineering or terraforming becomes common. Space travel is easy, travel across the planet is trivial even in private transport.

Anti-gravity technology is commonplace, replaces most wheeled vehicles.

Cybernetics is becoming common and good quality, though still mostly limited to medical reasons.

Larger freestanding holographic images are possible, models in shop window or full 3D vids.

Availability of cheap power is commonplace, so is rarely a limiting factor. Flying buildings are frequent, if not common.

Cybernetics is commonplace, even for basic enhancement. Augmented limbs or mood enhancement chips are possible.

Large building-sized free standing holograms are possible. Streets are full of holographic advertising, building fronts will tend to display whatever they desire, though they are obviously holographic in nature.