My brother's 1906 house has that, along with the original curb and brick gutter. No idea what the exact purpose is, but, I suspect it would have made sense for curbside carriage or early automobile to have an access across the parkway (easement with trees between the curb and sidewalk). The house does not have a front facing driveway; the garage is off an alley in the back and isn't even original to the house.