That's because current and former presidents and vice presidents are not allowed to operate motor vehicles on the open road.
For security reasons, high profile government officials and former officials, like Barack Obama and Joe Biden, as well as both Bill and Hillary Clinton, have to rely on their appointed secret service teams, who are trained in "evasive and defensive driving maneuvers."
The assassination of John F. Kennedy in 1963 was a turning point in this lifetime security requirement. Lyndon Johnson was the last president to drive on public roads.
Though the rule is not law, it's highly enforced by the secret service and all parties seem to adhere.
Ronald Reagan famously cherished joyrides in his beloved Jeep on his own ranch but was forbidden from claiming the driver's seat for highway drives.
And then-President Barack Obama told NBC's "The Tonight Show" in 2012 that he's only gone as far as a few circles around the South Lawn behind the wheel of a Chevy Volt.