A vehicle braking system includes a primary system including at least one pneumatic brake pipe control valve, and a secondary back-up system configured to facilitate vehicle braking without human intervention. The secondary back-up system includes a first air reservoir coupled to supply pressurized air to the at least one pneumatic brake pipe control valve, a second air reservoir, a choke adapted to allow airflow at a specified airflow rate, and a solenoid valve adapted to selectively couple and decouple the first air reservoir and the second air reservoir via the choke, according to an energization state of the solenoid valve.