Anti-gravity propulsion has been under development for almost a century now.* Initially seen in military applications, it eventually found its way to the consumer market. Here, it began showing up in various luxury items and devices, such as hoverboards and floating recliners.
Further refinement of this technology - together with advances in AI, microjets and collision avoidance systems - has led to the dawn of a new era in personal transportation. In the late 2070s, it is not uncommon to see what citizens of earlier decades might describe as "flying cars" moving through cities.
In fact, these are light-duty vehicles based on earlier military VTOL (Vertical Take-Off and Landing) craft, but with slimmed down functionality and costs. They come in a variety of models and sizes, but are typically around 4 metres wide, and limited to a maximum of one or two passengers. By the end of this decade, they are becoming cheap, safe and numerous enough to be regarded as a mainstream form of transport.
The craft have a number of advantages over established forms of mobility. Since they float above the ground, they can access terrain and environments that would easily defeat traditional automobiles. This makes them popular with adventurers and explorers. They are also substantially faster than normal cars, able to reach several hundred kilometres per hour if necessary. They are more versatile and manoeuvrable than aeroplanes and can utilise a much greater volume of airspace. Since the traffic they generate is decentralised and there is so much available airspace, this makes them safer than both cars and aeroplanes, too. Collisions are almost unheard of, in any case, due to the onboard software and AI.
In addition, they use considerably less fuel than earlier forms of transport and require less maintenance.
Some of the more expensive models are capable of reaching low Earth orbit for short periods. Others feature striking designs, often personalised by their owner - such as holographic decals and other accessories. These craft are being used by many businesses too (especially for rapid delivery of goods), as well as police and ambulance crews.
Further developments in anti-gravity will lead to bigger, more sophisticated versions - including recreational vehicles serving as truly mobile homes. Many previously inaccessible parts of Earth will become inhabited thanks to this, such as mountains and remote islands.