Two Rod, Three Rod, Four Rod roads
First, understand that a rod in this context is a unit of measure equal to 5-1/2 yards, 16-1/2 feet.
In 1826 a strip of land three and one-half miles long north-to-south and one mile wide east-to-west was purchased from the Indians in the Buffalo Creek Reservation.
Soon after the land sale of 1826 two roads were surveyed. One ran from Portersville to the Village of Marilla, and from there to Alden, and touched the territory still occupied by the Indians. It had been expected that the latter would voluntarily surrender half of the land to be used for road purposes, or that it would be bought, and for that reason the town officials had surveyed only two rods wide. From that fact it got the name of "Two Rod Road", which it still bears, although it has been widened long ago. The other road ran parallel to the first one, and was called the "Four Rod Road."In other words, they surveyed a road two rods wide - thirty-three feet - along the boundary of the newly purchased land, figuring that the other half of the road would be acquired from the Indians. That did not happen immediately, so the road was only two rods wide for a time.
The other road mentioned was surveyed at its full width of four rods, sixty-six feet.
There is no mention of it in the book, but presumably Three Rod Road was, well, three rods wide.