President Trump took an entire motorcade from the White House to Blair House:
President Trump traversed a wide political chasm Tuesday evening when he personally welcomed George W. Bush, his occasional foil, to Blair House, the presidential guest quarters across Pennsylvania Avenue from the White House.
But the actual distance was just 250 yards — a route Trump and his wife Melania traveled in the presidential parade limousine, with a motorcade of at least seven other vehicles.
White House aides declined to comment when asked why the Trumps chose to take a motorcade and whether it was related to security.
In her autobiography “Becoming,” former first lady Michelle Obama wrote that the Secret Service sometimes requested she or her husband “take the motorcade instead of walking in the fresh air” to Blair House for security reasons.
A search of Internet archives found at least six occasions when President Obama walked from the White House to Blair House. The search did not immediately find any times he took a motorcade, other than when he and Michelle left Blair House after spending the night on Inauguration Day in January 2009 and traveled to St. John’s Church for a prayer service.
Here's a satellite photo of the vast distance between the two buildings:
I can totally understand why he needed to drive.