Not just a man hole size, but an entire 'bridge'. The area in front of a house I'm designing is meant to be in the air (picture a bridge running 20 feet, 2 lanes wide from the street to the house garage).
The site is a steep slope.
I'm envisioning this 4" thick, grated metal that would be able to carry a car, but not trap someones foot when they get out the car.
Thanks in Advance.