  Since the development of transport systems, humans have exploited
ground-level, below-ground, and high-altitude spaces for transportation
purposes. However, with the increasing burden of expanding populations and
rapid urbanization in recent decades, public transportation systems and freight
traffic are suffering huge pressure, plaguing local governments and straining
economies. Engineers and researchers have started to re-examine, propose, and
develop the underused near-ground spaces (NGS) for transportation purposes. For
instance, flying cars, which are not a totally novel idea, aim at solving the
traffic congestion problem and releasing the strains on existing city transport
networks by utilizing unoccupied NGS. Flying cars differ from traditional
grounded transportation systems that are entirely limited by their physical
space, such as trains on tracks or automobiles on roads. Flying cars do not
occupy or compete for high-altitude spaces used by air traffic for
long-distance transfer. However, there is a clear lack of specific literature
on flying cars and flying car transportation systems (FCTS), which this paper
aims to address by describing modern advances, techniques, and challenges of
FCTS. We explore the inherent nature of NGS transportation and devise useful
proposals to facilitate the construction and commercialization of FCTS. We
begin with an introduction to the increasing need for NGS transportation and we
address the advantages of using flying cars. Next, we present a brief overview
of the history of the development of flying cars in terms of the historic
timeline and technique development. Then, we discuss and compare the state of
the art in the design of flying cars, including the take-off \& landing (TOL)
modes, pilot modes, operation modes, and power types, ...
