Highway 20, more commonly known as the Ayalon Highway, or simply Ayalon, is a major inter city freeway in Gush Dan, Israel. The road runs along the eastern border of central Tel Aviv from north to south and connects all of the major highways leading to the city—such as Highway 4 from Ashdod and the Southern regions, Highway 2 from Haifa and the Northern regions, Highway 5 from the East, and Highway 1 from Jerusalem and the Southeast. The Ayalon Highway is heavily used; on an average day, almost 600,000 vehicles enter the freeway. It consists of a multi-lane highway with a multi-track railway located between the opposite travel lanes. Some of the highway's route is along the Ayalon River, hence its name. It is made of primarily asphalt.

Gush Dan or Tel Aviv metropolitan area is a conurbation in Israel, located along the country's Mediterranean coastline. There is no single formal definition of Gush Dan, though the term is in frequent use by both governmental bodies and the general public. It ranges from combining Tel Aviv with cities that form an urban continuum with it, to the entire areas from both the Tel Aviv District and the Central District, or sometimes the whole Metropolitan Area of Tel Aviv, which includes a small part of the Southern District as well. Gush Dan is the largest conurbation and metropolitan area in Israel, with the metropolitan area having an estimated population of 4,156,900 residents, 89% of whom are Israeli Jews.