Law enforcement say the trucks are being used to form a barrier to minimize an attack with explosive devices. The trucks are parked outside Trump Tower and the Hilton Hotel, where Donald Trump is expected to host his election after party. The sand-filled trucks are also being used in a similar manner in front of Hillary Clintons designated locations, including the Peninsula Hotel the and Javits Center. This tactic has been used before, including in 1983 when the Reagans were dealing with a bomb scare during Thanksgiving.”]
Source: https://gizmodo.com/heavy-dump-trucks-are-protecting-clinton-and-trump-from-1788720581