The Del Ray ramp and Belanger Park ramp both close up for the night.
The Ecorse and Wyandotte ramp used to stay open. Ecorse would leave the exit Gate un-locked but I have heard they are closing it at night. As for Wyandotte he has been known to string the chain across the ramp at night. They say it is under the orders of the U.S. Border Patrol, don't know if it is true or not.