Autonomous cars rely heavily on a GPS signal to get around, but as many streets become densely populated by tall buildings on both sides, the signal at ground level can be lost or degraded. This is because satellite signals are obscured, or because radio waves bounce off surroundings and form multiple signal paths.
According to the Council on Tall Buildings and Urban Habitat (CTBUH), the number of tall buildings (above 200 metres) has risen by 650% in the last five years. This is set to increase again by up to 20% in 2020.
These tall buildings are not the only issue with GPS dependency. Sunspots formed during the sun’s 11-year magnetic field cycle cause marked changes in the solar wind. This subsequently impacts the upper atmosphere which can in turn interfere with GPS satellites.